Reservoir engineering functions include determining hydrocarbon reserves and production rates. A reservoir engineer's role includes reserves estimation, development planning, and production optimization. Reserves are classified as proven or unproven. Reservoir properties like porosity and permeability control production potential. Porosity is measured from logs or cores, and permeability is measured from cores, well tests, or logs. Relative permeability curves describe fluid flow at partial saturations. Wettability and capillary pressure also impact fluid distribution and flow.
This document discusses reservoir characteristics, rock and fluid properties, and drive mechanisms. It provides information on:
1) Techniques like seismic data, well logging, core analysis, and well testing that are used to understand the reservoir and develop an accurate reservoir model.
2) Reservoir characteristics including rock type, porosity, permeability, and factors that allow hydrocarbon accumulation like sufficient pore space and traps.
3) Rock properties such as porosity, permeability, and how they impact fluid flow.
4) Fluid properties including phase behavior under varying pressures and temperatures, properties of different fluid types, and sampling techniques.
5) Common experiments done to analyze reservoir fluids using pressure-volume-temperature cells
That is my presentation for my grad research about reservoir geomechanics, hope you find it useful, and my source book was reservoir geomechanics for prof Mark Zoback, soon the PDF copy will be available as well.
This document discusses well testing and well test analysis software programs. It provides information on:
- The objectives of well testing including identifying fluid types and reservoir parameters
- Types of well tests including productivity tests for development wells and descriptive tests for exploration wells
- Popular well test software programs for analytical and numerical analysis including Saphir, PanSystem, Interpret 2000, and Weltest 200
- An overview of the Weltest 200 program which links analytical and numerical well test analysis through different modules
- Using an example of liquid productivity or IPR testing to demonstrate how well test data is incorporated and analyzed in the software
This document provides information about reservoir engineering. It discusses how reservoir engineers use tools like subsurface geology, mathematics, and physics/chemistry to understand fluid behavior in reservoirs. It also describes different well classes used for injection/extraction, environmental impacts of enhanced oil recovery, and various reservoir engineering techniques like simulation modeling, production surveillance, and evaluating volumetric sweep efficiency. Thermal and chemical enhanced oil recovery methods are explained, including gas, steam, polymer, surfactant, microbial and in-situ combustion injection.
The reservoir (rock porosity and permeability)salahudintanoli
Reservoir rock is the one of the important component in petroleum system i.e without it petroleum system is impossible. This presentation contain all necessary information regarding reservoir rock.
Team M Reservoir simulation-an extract from original pptMukesh Mathew
This document summarizes reservoir simulation work for an oil field. Static and dynamic reservoir models were created using well logs, core data, and production data. Multiple development scenarios were simulated including natural depletion, water flooding, gas injection, and EOR methods. The optimum scenario involved 13 producer wells and 8 water injector wells, achieving a recovery factor of 55% over 25 years. Alternate scenarios like gas injection and polymer flooding were also considered.
This document discusses reservoir characteristics, rock and fluid properties, and drive mechanisms. It provides information on:
1) Techniques like seismic data, well logging, core analysis, and well testing that are used to understand the reservoir and develop an accurate reservoir model.
2) Reservoir characteristics including rock type, porosity, permeability, and factors that allow hydrocarbon accumulation like sufficient pore space and traps.
3) Rock properties such as porosity, permeability, and how they impact fluid flow.
4) Fluid properties including phase behavior under varying pressures and temperatures, properties of different fluid types, and sampling techniques.
5) Common experiments done to analyze reservoir fluids using pressure-volume-temperature cells
That is my presentation for my grad research about reservoir geomechanics, hope you find it useful, and my source book was reservoir geomechanics for prof Mark Zoback, soon the PDF copy will be available as well.
This document discusses well testing and well test analysis software programs. It provides information on:
- The objectives of well testing including identifying fluid types and reservoir parameters
- Types of well tests including productivity tests for development wells and descriptive tests for exploration wells
- Popular well test software programs for analytical and numerical analysis including Saphir, PanSystem, Interpret 2000, and Weltest 200
- An overview of the Weltest 200 program which links analytical and numerical well test analysis through different modules
- Using an example of liquid productivity or IPR testing to demonstrate how well test data is incorporated and analyzed in the software
This document provides information about reservoir engineering. It discusses how reservoir engineers use tools like subsurface geology, mathematics, and physics/chemistry to understand fluid behavior in reservoirs. It also describes different well classes used for injection/extraction, environmental impacts of enhanced oil recovery, and various reservoir engineering techniques like simulation modeling, production surveillance, and evaluating volumetric sweep efficiency. Thermal and chemical enhanced oil recovery methods are explained, including gas, steam, polymer, surfactant, microbial and in-situ combustion injection.
The reservoir (rock porosity and permeability)salahudintanoli
Reservoir rock is the one of the important component in petroleum system i.e without it petroleum system is impossible. This presentation contain all necessary information regarding reservoir rock.
Team M Reservoir simulation-an extract from original pptMukesh Mathew
This document summarizes reservoir simulation work for an oil field. Static and dynamic reservoir models were created using well logs, core data, and production data. Multiple development scenarios were simulated including natural depletion, water flooding, gas injection, and EOR methods. The optimum scenario involved 13 producer wells and 8 water injector wells, achieving a recovery factor of 55% over 25 years. Alternate scenarios like gas injection and polymer flooding were also considered.
- The document discusses reservoir characteristics including rock and fluid properties that are important to understand for optimal hydrocarbon recovery. Techniques like seismic data, well logging, and testing provide valuable data to build reservoir models.
- Key rock properties that impact hydrocarbon storage and flow include porosity, permeability, and wettability. Core analysis in the lab and well logs provide data on these properties.
- Understanding fluid properties like phase behavior under reservoir conditions of pressure and temperature is also important for predicting production performance and fluid composition.
This document discusses using the Ensemble Kalman Filter (EnKF) for history matching and production forecasts of oil reservoirs. It presents the EnKF algorithm and applies it to a synthetic 3D reservoir model. The EnKF allows updating reservoir properties like porosity and permeability from production data. Results show the EnKF ensemble matches observations better than without updating. Further work is needed to study the impact of observation availability and representativeness of the ensemble.
This document discusses formation damage, which is a reduction in permeability near the wellbore caused by drilling or treatment fluids. It outlines various causes of formation damage including clay swelling, fluid invasion, and fines migration. The effects are reduced well performance and sub-optimal oil production. Control methods include improved drilling fluids, acid stimulation to dissolve mineral deposits, and hydraulic fracturing. Acidization specifically involves spotting acid to restore permeability by dissolving damaged materials and allowing reservoir fluids to flow freely again.
The document discusses various natural reservoir drive mechanisms that provide energy for hydrocarbon production including:
1) Solution gas drive where dissolved gas expands due to pressure drop, providing 5-25% oil recovery.
2) Gas cap drive where free gas expansion drives production, providing 20-40% oil recovery.
3) Water drive where aquifer water influx provides pressure to displace oil, providing 35-75% oil recovery.
4) Gravity drainage where gas migrates updip and oil downdip in high dip reservoirs.
This document discusses methods for calculating hydrocarbon volumes in reservoirs, including volumetric and material balance methods. It provides details on calculating oil, gas, and total hydrocarbon volumes based on parameters like porosity, net thickness, and saturation. It also covers reservoir drive mechanisms that can provide energy for hydrocarbon production, such as solution gas drive, gas cap drive, water drive, compaction drive, and combination drives. Reservoir performance data like pressure trends and gas-oil ratios can help identify the active drive mechanism.
Introduction to Reservoir Rock & Fluid PropertiesM.T.H Group
This document discusses reservoir rock properties and how core samples are used to characterize reservoirs. Reservoir rocks must have porosity and permeability to store and transmit fluids. Core samples provide information on lithology, porosity, permeability and other properties essential for evaluating a reservoir's fluid storage and flow capabilities. Whole core samples are most representative but sidewall cores provide additional data points. Both core types are analyzed to understand factors like relative permeability needed for reservoir modeling and production forecasting.
The acidizing is pumping of the acids into the wellbore to remove near well formation damage and other damaging substances, matrix acidizing is applied primarily to remove skin damage that caused by drilling, completion, work over, well killing or injection fluids.
This project is concerned with carbonate reservoirs that exceeded in Kurdistan subsurface formations.
Conduct a case study using real industrial data of Arab-D formation (Ghawar oil field – Saudi Arabia) which has five water wells were treated with 50 gallon of HCl acid The treatment acid was placed with coiled tubing and foam was used as diverter. The foam was made from nitrogen, water and surfactants.
Water injection pressure, injection rate and injection flow meter profiles prior to and after the treatment for the five wells show optimistic results to an acceptable extent
In coiled tubing acid placement, the coiled tubing/borehole annulus is usually filled with acid which allow the acid to be in contact with the entire zone at bottom hole temperature condition. This reduces the degree of diversion effectiveness.
Recommend people who work in carbonate reservoirs they should done their work on petrophysical analysis and the porosity should not have exceeded by the acids
This document summarizes the process of reservoir modeling and simulation for the Saldanadi Gas Field in Bangladesh using Petrel 2009.1.1 and FrontSim software. The workflow includes collecting seismic, well, and production data; interpreting horizons and faults from seismic lines; developing structural and stratigraphic models; modeling properties; simulating initial conditions and production; and history matching simulation results to field data. The objectives are to better understand reservoir characteristics, locate new wells, and forecast production and investment needs to further develop the field.
Performance prediction in gas condensate reservoirGowtham Dada
This document discusses performance prediction in gas condensate reservoirs. It describes key characteristics of gas condensate reservoirs including the production of both gas and condensate liquids. Condensate formation occurs near the wellbore as pressure drops, which can impair well productivity over time due to liquid dropout. The document outlines factors that influence multiphase flow behavior in the reservoir such as interfacial tension, gravity effects, relative permeability, and non-Darcy flow near the wellbore. It also reviews methods that can be used to reduce condensate banking issues like hydraulic fracturing, solvent injection, and wettability alteration.
1. The document discusses various well logging tools and concepts used in petrophysical interpretation. It describes tools such as the spontaneous potential (SP) log, gamma ray (GR) log, resistivity logs including induction and lateral logs, and porosity logs.
2. Key concepts covered include the logging environment and factors that impact tool measurements like borehole conditions and mud properties. Interpretation techniques for evaluating permeable zones, formation resistivity, water saturation, and porosity are also summarized.
3. The document provides examples of using tools and concepts like the Archie formula to calculate water resistivity, determine hydrocarbon presence, and evaluate clean versus shaly formations. It also discusses corrections that must be applied to well log
- Reservoirs are classified based on the composition of hydrocarbons present, initial reservoir pressure and temperature, and the pressure and temperature of produced fluids.
- A pressure-temperature diagram is used to classify reservoirs and describe the phase behavior of reservoir fluids, delineating the liquid, gas, and two-phase regions.
- Based on the diagram, reservoirs are classified as oil reservoirs if the temperature is below the critical temperature, and gas reservoirs if above the critical temperature.
Reservoir engineering functions include estimating oil and gas reserves, developing field development plans, and optimizing production operations. Key activities are reserves estimation using volumetric and material balance methods, developing static and dynamic reservoir models for planning, and history matching production data to simulate and predict future performance. Reservoir traps that contain hydrocarbons include structural traps from folding and faulting of rock layers, stratigraphic traps due to permeability changes within layers, and combination traps involving salt dome intrusions.
This document provides guidance for a quick log analysis by a petrophysicist. It outlines the key sections to include such as well summary, regional geology, strathigraphy, hydrocarbon and pressure analyses. For each test or analysis, it recommends displaying the relevant well logs and providing interpretations to justify conclusions. It also provides examples of how to summarize key information like hydrocarbon shows, test profiles, and pressure analyses. Pressure data can be used to determine reservoir fluid contacts while sonic logs can identify regional overpressure zones. Drilling data is discussed though noted to be more relevant for drilling engineers than geologists.
1) Sedimentary basins are regions where thick layers of sediment have accumulated, up to 20 km deep in some cases. They form primarily through the extension of tectonic plates.
2) Most sedimentary basins contain source rocks rich in organic matter that generate hydrocarbons like oil and gas during burial and heating over geological time.
3) If the right combination of source, reservoir, seal and timing conditions exist within a sedimentary basin, significant accumulations of oil and gas can be discovered and produced from conventional reservoirs.
This document provides an overview of a reservoir engineering course focused on fundamental rock properties. It discusses key topics like porosity, saturation, wettability, capillary pressure, and how they are determined through laboratory core analysis. Porosity refers to the pore space available to hold fluids and is classified as absolute or effective porosity. Saturation represents the fraction of pore space occupied by a fluid. Capillary pressure describes the pressure differential between immiscible fluids based on interface curvature. Laboratory tests on core samples are used to characterize these important rock properties.
This document discusses water injection techniques for secondary oil recovery including:
- Water injection maintains reservoir pressure and improves sweep efficiency. Calculations of IVC and CVC are used to evaluate injection schemes.
- Performance plots show increased oil rates and water cuts rising after starting injection.
- A profile modification job using polymers controlled injection into specific intervals of a well and reduced water cuts in offset producers.
- Low salinity water flooding can improve oil recovery through wettability alteration and is a potential enhanced oil recovery method.
This document provides information on estimating oil and gas reserves. It defines various classifications of reserves from proven to unproven, and how reserves are estimated using volumetric, material balance, and production performance methods. The key classifications discussed are proven and probable reserves, with proven reserves having a 90% certainty of recovery and probable having 50% certainty. Volumetric estimation calculates initial hydrocarbon volumes using parameters like rock volume, porosity, fluid properties, and recovery factors.
The document discusses various oil recovery techniques, focusing on waterflooding. It summarizes that waterflooding involves injecting water into reservoirs to increase pressure and displace oil towards production wells, potentially recovering up to 50% of oil originally in place. The document discusses factors in choosing between peripheral and pattern water injection schemes and describes various pattern designs, noting 5-spot and 7-spot patterns are commonly used.
This document provides an overview of the design process for a new diversion dam project on the Tarbela Dam in Pakistan. It discusses selecting the site, conducting site studies to understand the geology and foundation conditions, determining the appropriate dam type is an earth-fill dam, designing the embankment, investigating the reservoir area, conducting test fills, studying causes of dam failure, developing the flood hydrograph, and collecting basic hydrologic and meteorological data. The project will require detailed exploration of the foundation and subsurface conditions to support the earth-fill dam design and ensure the stability and safety of the new diversion dam.
This presentation covers an imaginary design of diversion dam in Tarbela dam Pakistan. The design covers all the prospects of dam engineering, from basics dam planning to construction.
- The document discusses reservoir characteristics including rock and fluid properties that are important to understand for optimal hydrocarbon recovery. Techniques like seismic data, well logging, and testing provide valuable data to build reservoir models.
- Key rock properties that impact hydrocarbon storage and flow include porosity, permeability, and wettability. Core analysis in the lab and well logs provide data on these properties.
- Understanding fluid properties like phase behavior under reservoir conditions of pressure and temperature is also important for predicting production performance and fluid composition.
This document discusses using the Ensemble Kalman Filter (EnKF) for history matching and production forecasts of oil reservoirs. It presents the EnKF algorithm and applies it to a synthetic 3D reservoir model. The EnKF allows updating reservoir properties like porosity and permeability from production data. Results show the EnKF ensemble matches observations better than without updating. Further work is needed to study the impact of observation availability and representativeness of the ensemble.
This document discusses formation damage, which is a reduction in permeability near the wellbore caused by drilling or treatment fluids. It outlines various causes of formation damage including clay swelling, fluid invasion, and fines migration. The effects are reduced well performance and sub-optimal oil production. Control methods include improved drilling fluids, acid stimulation to dissolve mineral deposits, and hydraulic fracturing. Acidization specifically involves spotting acid to restore permeability by dissolving damaged materials and allowing reservoir fluids to flow freely again.
The document discusses various natural reservoir drive mechanisms that provide energy for hydrocarbon production including:
1) Solution gas drive where dissolved gas expands due to pressure drop, providing 5-25% oil recovery.
2) Gas cap drive where free gas expansion drives production, providing 20-40% oil recovery.
3) Water drive where aquifer water influx provides pressure to displace oil, providing 35-75% oil recovery.
4) Gravity drainage where gas migrates updip and oil downdip in high dip reservoirs.
This document discusses methods for calculating hydrocarbon volumes in reservoirs, including volumetric and material balance methods. It provides details on calculating oil, gas, and total hydrocarbon volumes based on parameters like porosity, net thickness, and saturation. It also covers reservoir drive mechanisms that can provide energy for hydrocarbon production, such as solution gas drive, gas cap drive, water drive, compaction drive, and combination drives. Reservoir performance data like pressure trends and gas-oil ratios can help identify the active drive mechanism.
Introduction to Reservoir Rock & Fluid PropertiesM.T.H Group
This document discusses reservoir rock properties and how core samples are used to characterize reservoirs. Reservoir rocks must have porosity and permeability to store and transmit fluids. Core samples provide information on lithology, porosity, permeability and other properties essential for evaluating a reservoir's fluid storage and flow capabilities. Whole core samples are most representative but sidewall cores provide additional data points. Both core types are analyzed to understand factors like relative permeability needed for reservoir modeling and production forecasting.
The acidizing is pumping of the acids into the wellbore to remove near well formation damage and other damaging substances, matrix acidizing is applied primarily to remove skin damage that caused by drilling, completion, work over, well killing or injection fluids.
This project is concerned with carbonate reservoirs that exceeded in Kurdistan subsurface formations.
Conduct a case study using real industrial data of Arab-D formation (Ghawar oil field – Saudi Arabia) which has five water wells were treated with 50 gallon of HCl acid The treatment acid was placed with coiled tubing and foam was used as diverter. The foam was made from nitrogen, water and surfactants.
Water injection pressure, injection rate and injection flow meter profiles prior to and after the treatment for the five wells show optimistic results to an acceptable extent
In coiled tubing acid placement, the coiled tubing/borehole annulus is usually filled with acid which allow the acid to be in contact with the entire zone at bottom hole temperature condition. This reduces the degree of diversion effectiveness.
Recommend people who work in carbonate reservoirs they should done their work on petrophysical analysis and the porosity should not have exceeded by the acids
This document summarizes the process of reservoir modeling and simulation for the Saldanadi Gas Field in Bangladesh using Petrel 2009.1.1 and FrontSim software. The workflow includes collecting seismic, well, and production data; interpreting horizons and faults from seismic lines; developing structural and stratigraphic models; modeling properties; simulating initial conditions and production; and history matching simulation results to field data. The objectives are to better understand reservoir characteristics, locate new wells, and forecast production and investment needs to further develop the field.
Performance prediction in gas condensate reservoirGowtham Dada
This document discusses performance prediction in gas condensate reservoirs. It describes key characteristics of gas condensate reservoirs including the production of both gas and condensate liquids. Condensate formation occurs near the wellbore as pressure drops, which can impair well productivity over time due to liquid dropout. The document outlines factors that influence multiphase flow behavior in the reservoir such as interfacial tension, gravity effects, relative permeability, and non-Darcy flow near the wellbore. It also reviews methods that can be used to reduce condensate banking issues like hydraulic fracturing, solvent injection, and wettability alteration.
1. The document discusses various well logging tools and concepts used in petrophysical interpretation. It describes tools such as the spontaneous potential (SP) log, gamma ray (GR) log, resistivity logs including induction and lateral logs, and porosity logs.
2. Key concepts covered include the logging environment and factors that impact tool measurements like borehole conditions and mud properties. Interpretation techniques for evaluating permeable zones, formation resistivity, water saturation, and porosity are also summarized.
3. The document provides examples of using tools and concepts like the Archie formula to calculate water resistivity, determine hydrocarbon presence, and evaluate clean versus shaly formations. It also discusses corrections that must be applied to well log
- Reservoirs are classified based on the composition of hydrocarbons present, initial reservoir pressure and temperature, and the pressure and temperature of produced fluids.
- A pressure-temperature diagram is used to classify reservoirs and describe the phase behavior of reservoir fluids, delineating the liquid, gas, and two-phase regions.
- Based on the diagram, reservoirs are classified as oil reservoirs if the temperature is below the critical temperature, and gas reservoirs if above the critical temperature.
Reservoir engineering functions include estimating oil and gas reserves, developing field development plans, and optimizing production operations. Key activities are reserves estimation using volumetric and material balance methods, developing static and dynamic reservoir models for planning, and history matching production data to simulate and predict future performance. Reservoir traps that contain hydrocarbons include structural traps from folding and faulting of rock layers, stratigraphic traps due to permeability changes within layers, and combination traps involving salt dome intrusions.
This document provides guidance for a quick log analysis by a petrophysicist. It outlines the key sections to include such as well summary, regional geology, strathigraphy, hydrocarbon and pressure analyses. For each test or analysis, it recommends displaying the relevant well logs and providing interpretations to justify conclusions. It also provides examples of how to summarize key information like hydrocarbon shows, test profiles, and pressure analyses. Pressure data can be used to determine reservoir fluid contacts while sonic logs can identify regional overpressure zones. Drilling data is discussed though noted to be more relevant for drilling engineers than geologists.
1) Sedimentary basins are regions where thick layers of sediment have accumulated, up to 20 km deep in some cases. They form primarily through the extension of tectonic plates.
2) Most sedimentary basins contain source rocks rich in organic matter that generate hydrocarbons like oil and gas during burial and heating over geological time.
3) If the right combination of source, reservoir, seal and timing conditions exist within a sedimentary basin, significant accumulations of oil and gas can be discovered and produced from conventional reservoirs.
This document provides an overview of a reservoir engineering course focused on fundamental rock properties. It discusses key topics like porosity, saturation, wettability, capillary pressure, and how they are determined through laboratory core analysis. Porosity refers to the pore space available to hold fluids and is classified as absolute or effective porosity. Saturation represents the fraction of pore space occupied by a fluid. Capillary pressure describes the pressure differential between immiscible fluids based on interface curvature. Laboratory tests on core samples are used to characterize these important rock properties.
This document discusses water injection techniques for secondary oil recovery including:
- Water injection maintains reservoir pressure and improves sweep efficiency. Calculations of IVC and CVC are used to evaluate injection schemes.
- Performance plots show increased oil rates and water cuts rising after starting injection.
- A profile modification job using polymers controlled injection into specific intervals of a well and reduced water cuts in offset producers.
- Low salinity water flooding can improve oil recovery through wettability alteration and is a potential enhanced oil recovery method.
This document provides information on estimating oil and gas reserves. It defines various classifications of reserves from proven to unproven, and how reserves are estimated using volumetric, material balance, and production performance methods. The key classifications discussed are proven and probable reserves, with proven reserves having a 90% certainty of recovery and probable having 50% certainty. Volumetric estimation calculates initial hydrocarbon volumes using parameters like rock volume, porosity, fluid properties, and recovery factors.
The document discusses various oil recovery techniques, focusing on waterflooding. It summarizes that waterflooding involves injecting water into reservoirs to increase pressure and displace oil towards production wells, potentially recovering up to 50% of oil originally in place. The document discusses factors in choosing between peripheral and pattern water injection schemes and describes various pattern designs, noting 5-spot and 7-spot patterns are commonly used.
This document provides an overview of the design process for a new diversion dam project on the Tarbela Dam in Pakistan. It discusses selecting the site, conducting site studies to understand the geology and foundation conditions, determining the appropriate dam type is an earth-fill dam, designing the embankment, investigating the reservoir area, conducting test fills, studying causes of dam failure, developing the flood hydrograph, and collecting basic hydrologic and meteorological data. The project will require detailed exploration of the foundation and subsurface conditions to support the earth-fill dam design and ensure the stability and safety of the new diversion dam.
This presentation covers an imaginary design of diversion dam in Tarbela dam Pakistan. The design covers all the prospects of dam engineering, from basics dam planning to construction.
The document discusses reservoir petrophysics, which is the study of rock properties and interactions with fluids. It describes a course on reservoir petrophysics that systematically studies physical rock properties including porosity, permeability, fluid saturation, and fluid-rock interactions. The course objectives are to define key concepts and demonstrate techniques for determining properties like porosity, permeability, and fluid saturation through experiments and calculations.
The document provides details on the design of a new diversion dam project at the Tarbela Dam in Pakistan. It discusses selecting the site, conducting site studies and subsurface explorations, selecting an earth-fill dam type, and considerations for the embankment, foundation geology, reservoir investigations, test fills, flood hydrology, engineering design aspects like capacity and power calculations, penstock selection and construction details. Foundation conditions, causes of dam failures, and administrative requirements are also outlined.
This document provides information on various topics related to well planning and design, including:
- Well data requirements such as detailed lithology, formation fluids, reservoir data, and pressure data.
- Global basin screening, basin analysis, play analysis, prospect analysis, rock types, and reactive formations.
- Exploration strategy, including global basin analysis, basin analysis, play analysis, prospect analysis, and prospect volume estimation.
- Pore pressure and fracture pressure determination, including leakage tests to estimate the fracture gradient at casing seats.
Reservoir engineering involves estimating oil and gas reserves within underground formations. Reservoir engineers determine the volume of hydrocarbons originally in place and the fraction that can be recovered using production methods over time. Estimating reserves requires understanding properties like porosity, which is the proportion of void space within a rock that can contain fluids. Porosity values are measured through lab analysis of core samples and well logs, and can range widely between reservoir types and impact recoverable volumes.
Abstract This case study examines the formation damage that occurred i.pdfatozbazar
Abstract This case study examines the formation damage that occurred in an oil field located in
the Casanare region of Colombia. The oil field had been producing oil for several years, but the
operators noticed a significant decline in production rates. The investigation revealed that the
well was suffering from severe formation damage, which was caused by the accumulation of
drilling fluids and other contaminants in the reservoir. To address the formation damage, the
operators implemented a variety of remediation techniques, including acid stimulation, matrix
acidizing, and hydraulic fracturing. These techniques were designed to dissolve the contaminants
in the reservoir and increase the permeability of the formation, allowing oil to flow more easily
to the wellbore and to the understanding of formation damage mechanisms. The Ruba field is
one of the largest oil fields in Colombia and has been in production since the 1980 s. The oil
extracted from the Ruba field is a heavy crude oil, which requires more advanced refining
techniques to produce high-quality fuels. The Ruba field is operated by several major oil
companies, including Ecopetrol, the national oil company of Colombia. The concept of skin and
formation damage play a vital role in productivity of an oil well. The effect of formation damage
zone on the well flowing pressure was introduced to the original solution of diffusivity equation.
Formation damage reduces the well production. Skin defines as the area of reduced permeability
near the wellbore due to the invasion of drilling fluid into the reservoir rock. Classifying damage
requires a lot of work to determine correctly the main reason of it. In general, fluids can interact
with reservoir rock and cause formation damage that impedes hydrocarbon production. Tight
sandstone reservoir with well-developed natural fractures has a complex pore structure where
pores and pore throats have a wide range of diameters; formation damage in such type of
reservoir can be complicated and severe. Reservoir rock samples with a wide range of fracture
widths are tested through a several step core flood platform, where formation damage caused by
the drilling or fracturing fluid, where any unintentional fluid impedance in or out of a wellbore is
referred to as damage to formation. This general definition includes the flow restriction caused
by reduced permeability in the near wellbore region. Formation damage Description and
classification: The history of damage removal is a process that begins with the identification of
the issue. This usually involves looking through the various sources of information related to the
well, such as drilling records, completion designs, and operator experiments. The desired
purpose is to identify the causes of the formation damage and how it could be fixed. Where the
types of formation damage location of damage extent and screening of damage, and effect of
damage on well production or injection. Well development and res.
Reservoirs are constructed by building dams across rivers and streams to form artificial lakes. They require careful planning and design based on investigations of the site geology, hydrology, and topography. Reservoirs can serve multiple purposes including flood control, irrigation, water supply, hydroelectric power, navigation, and recreation. Depending on their primary purpose, reservoirs are classified as storage, flood control, distribution, or multipurpose. Key considerations for reservoir planning and design include selecting a suitable dam site, determining the required storage capacity based on water demand and inflows, and investigating the geology of the foundation and basin.
This document discusses unconventional reservoirs and shale gas. It begins with defining unconventional resources as hydrocarbon reservoirs with low permeability and porosity that are difficult to produce. Shale gas is then introduced as natural gas trapped in shale formations. The document outlines a roadmap for identifying and developing shale plays, including geological, geophysical, geochemical, and geomechanical approaches. Key factors like total organic carbon content, thermal maturity, and brittleness are examined. The concept of a "sweet spot" is introduced as the most prospective volumes within a shale play, characterized by properties like thickness and permeability. The document concludes with thanking the audience.
The document provides an overview of reservoir engineering functions and concepts. It discusses (1) estimating oil and gas reserves using volumetric and material balance methods, (2) development planning including static and dynamic reservoir modeling, and (3) production optimization such as history matching and primary/secondary/tertiary recovery. It also covers reservoir rock and fluid properties measurement including porosity, permeability, and relative permeability from core analysis. Reservoir traps are categorized as structural, stratigraphic, and combination types.
The document outlines the key steps for designing and managing an effective core analysis program, including appointing a program focal point, reviewing existing core data, designing the testing program with laboratory assistance, selecting a laboratory contractor, and preparing final reports. It also provides examples of specialized core analysis programs for different reservoir lithologies and examples of recommended routine and special core analysis tests for gas and oil reservoirs.
This document discusses reservoir characteristics including rock and fluid properties as well as drive mechanisms. It provides information on classifying rocks, characteristics needed for hydrocarbon reservoirs such as porosity and permeability, and how properties like grain size and wettability affect permeability. It also discusses fluid properties, phase behavior of hydrocarbon systems, and analysis techniques like coring and core analysis that provide data to understand the reservoir.
This document compares the design differences between water dams and tailings dams. Some key differences discussed include:
- Tailings dams must safely contain mine tailings and process water in perpetuity after closure, unlike water dams which typically have a 100 year design life.
- Seepage control is more critical for tailings dams due to environmental regulations around containment of contaminants from tailings.
- Tailings properties, such as higher specific gravity, can increase loading stresses on the dam compared to water.
- Tailings can be used advantageously in the design to reduce hydraulic gradients and piping risk, allow use of geosynthetic filters, and provide a seepage barrier, whereas water dams rely
This document provides an overview of reservoir petrophysics, including:
1) Petrophysics is the study of rock properties and interactions with fluids.
2) The course covers physical properties of reservoir rocks like porosity, permeability, fluid saturations, and their relationships.
3) The course objectives are to understand concepts like porosity, permeability, fluid saturations, and their measurement methods.
Here are brief responses to your questions:
A dam is a barrier built across a watercourse for retaining water.
We build dams for water supply, irrigation, hydroelectric power generation, flood control, recreation etc.
The main forces exerted on dams are water pressure, earth pressure, temperature stresses. Proper design is needed to withstand these forces.
Common dam types are gravity dams, arch dams, buttress dams, embankment dams based on construction material and design.
Key site conditions are impermeable foundation, adequate drainage, stable abutments, sufficient storage capacity.
Geological parameters include type and
This technical memorandum summarizes additional groundwater modeling analyses conducted for the Fort Lewis Department of the Army Public Works regarding the North Sequalitchew Creek project. The modeling analyses focused on updating inputs and incorporating new data from the last 4 years of monitoring in the Sequalitchew Creek basin. An updated model incorporated recent wetland water levels and flow data from the diversion canal. A second model explicitly included Sequalitchew Lake and conducted sensitivity analyses looking at dry year conditions and changing boundary conditions near Sequalitchew Springs. The revisions refined predictions of surface and groundwater interactions and results from both the updated and lake models continued to indicate drawdown at Sequalitchew Springs would be immeasurable.
This document discusses the role of water in calcium carbonate fillers used in moisture-sensitive adhesives and sealants. It explains that calcium carbonate readily absorbs water from the environment due to the rearrangement of ions on its surface. This absorbed water can cause issues in moisture-curing formulations. The document recommends treating calcium carbonate with fatty acids to hydrophobize its surface and minimize water absorption. It provides details on the mechanism of fatty acid treatment and its effectiveness at improving water resistance of calcium carbonate over a range of humidity levels.
The document discusses key concepts in oil and gas reservoir description and production geology. It lists various data sources used by production geologists to build static models of reservoirs, including mud logging, core, and well test data. Both static geological models and dynamic simulation are used to maximize production from oil and gas fields. The document also covers topics like reservoir rock types and porosity, permeability factors, fluid contacts, drive mechanisms, and volumetric and performance-based evaluation methods.
This document summarizes key issues in the design and construction of embankment dams. It discusses common causes of embankment dam failures such as sliding due to high pore water pressure, seepage failures from hydraulic fracturing, and differential settlement causing cracks. It also outlines investigation, design, and construction processes for embankment dams and analyzes total and effective stress for stability evaluations.
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6. The reservoir engineer in the multi-disciplinary perspective of modern oil and
gas
field management is located at the heart of many of the activities acting as a central
co-ordinating role in relation to receiving information processing it and passing it on
to others.
2-Introduction to Reservoir Engineering
6
7. The activities of reservoir engineering fall into the following three general
categories: Activities
of
Reservoir
Engineering
(A) Reserves Estimation
(B) Development Planning
(C) Production Operations Optimization
7
2-Introduction to Reservoir Engineering
8. (A) Reserves Estimation
The Society of Petroleum Engineers SPE and World Petroleum Congress
WPO1987
agreed classification of reserves3 provides a valuable standard by which to define
reserves, the section below is based on this classification document. :
8
9. (A) Reserves Estimation
9
Reserves :
are those quantities of petroleum which are anticipated to be commercially
recovered from known accumulations from a given date forward.
(A) Proven Reserves
Proven reserves are those quantities of petroleum which, by analysis of
geological
and engineering data, can be estimated with reasonable certainty to be
commercially
recoverable, from a given date forward, from known reservoirs and under current
economic conditions, operating methods, and government regulations.
There should be at least a 90 percent probability (P90) that the quantities actually
recovered will equal or exceed the estimate.
10. (A) Reserves Estimation
10
(B) Unproved Reserves
Unproved reserves are based on geologic and/or engineering data similar to that
used in estimates of proved reserves; but technical, contractual, economic, or
regulatory uncertainties preclude such reserves being classified as proved.
Unproved reserves may be further classified as probable reserves and possible
reserves.
1-Probable Reserves
•Those additional reserves that analysis of geoscience and engineering data
indicate are less likely to be recovered than proved reserves but more certain to be
recovered than possible reserves.
•There should be at least a 50 percent probability (P50) that the quantities actually
recovered will equal or exceed the estimate...
2-Possible Reserves
•Those additional reserves that analysis of geoscience and engineering data suggest
are less likely to be recoverable than probable reserves.
•There should be at least a 10 percent probability (P10) that the quantities actually
recovered will equal or exceed the estimate.
11. Relationships between parameters related with OOIP , RF and Reserve
RESERVES : Reserves are simply the oil or gas in place times the RF.
for an oil reservoir:
for a gas reservoir:
Recovery Factor ( RF)
11
12. Relationships between parameters related with OOIP , RF and Reserve
OOIP
RF
12
Reserves = OOIP X RF
OOIP : Original Oil in place
RF : Recovery factor
14. (B) Development Planning
1. Static model
2. Dynamic Model
3. Techno-economics
4. Uncertainty
The following list summarises some of the principal uncertainties
associated with the performance of the overall reservoir model.The
type of data can for example be subdivided into two aspects “static”
and “dynamic” data .
Static Properties
• Reservoir structure
• Reservoir properties
• Reservoir sand connectivity
• Impact of faults
• “thief” sands
Dynamic Properties
• Relative permeability etc
• Fluid properties
• Aquifer behavior
• Well productivity (fractures, well-type, condensate drop outetc.)
14
15. (C) Production Operations Optimization
1-History Matching
The purpose of history matching is to calibrate the numerical simulation model
so that it can be used to reasonably predict the future performance of the
reservoir(s) under various development and operating scenarios
15
16. (C) Production Operations Optimization
16
2-Phases of Development
During the development there are a number of phases. Not all of these phases
may be part of the plan. There is the initial production build up to the capacity
of the facility
There is the plateau phase where the reservoir is produced at a capacity
limited by the associated production and processing facilities. Different
companies work with different lengths of the plateau phase and each project
will have its own duration. There comes a point when the reservoir is no longer
able to deliver fluids at this capacity and the reservoir goes into the decline
phase. The
decline phase can be delayed by assisting the reservoir to produce the fluids
by the use of for example ‘lifting’ techniques such as down-hole pumps and
gas lift. The decline phase is often a difficult period to model and yet it can
represent a significant amount of the reserves
21. Structural Traps
Structural Traps
Structural traps are created by the deformation of rock strata within the earth’s crust. This
deformation can be caused by horizontal compression or tension, vertical movement and
differential compaction, which results in the folding, tilting and faulting within sedimentary
rock formations
Fault Trap
The faulting of
stratified rock occurs as a result of
vertical and horizontal stress. At
some point the rock layers break,
resulting in the rock faces alongthe
fracture moving or slipping past
each other into an offsetposition.
A fault trap is formed when the
faulted formations are tiltedtoward
the vertical. When a non-porous
rock face is moved into a position
above and opposite a porous rock
face, it seals off the natural flow of
the hydrocarbons allowing them to
accumulate.
21
22. Structural Traps
Fold (Anticlinal) and Dome Trap
The rock layers
in an anticlinal trapwere
originally laid down
horizontally then folded
upward into an arch or
dome. Later,
hydrocarbons migrate
into the porous and
permeable reservoir
rock. A cap or seal
(impermeable layer of
rock) is required to
permit the accumulation
of the hydrocarbon
22
23. Stratigraphic Traps
23
Stratigraphic traps
are formed as a
result of differences or variations
between or within stratified rock
layers, creating a change or lossof
permeability from one area to
another. These traps do not occur
as
a result of movement of the strata.
24. Combination Traps
Salt Dome or Salt Plug Trap
A trap created by piercement or
intrusion of stratified rock layers from
below by ductile nonporous salt. The
intrusion causes the lower formations
nearest the intrusion to be upliftedand
truncated along the sides of the
intrusion, while layers above are
uplifted creating a dome or anticlinal
folding. Hydrocarbons migrate into
the porous and permeable beds onthe
sides of the column of salt.
Hydrocarbons accumulate in the traps
around the outside of the salt plug if a
seal or cap rock is present.
24
27. (4) Basic Rock and Fluid Properties
27
There are four fundamental types of properties of a hydrocarbon reservoir
that control its initial contents, behavior, production potential, and hence
its reserves.
1. The rock properties of porosity, permeability, and compressibility, which
are all dependent on solid grain/particle arrangements and packing.
2.The wettability properties, capillary pressure, phase saturation, and relative
permeability, which are dependent on interfacial forces between the
solid and the water and hydrocarbon phases.
3.The initial ingress of hydrocarbons into the reservoir trap and the
thermodynamics of the resulting reservoir mixture composition.
4. Reservoir fluid properties, phase compositions, behavior of the phases
with pressure, phase density, and viscosity.
29. Generally can estimate rock properties from core Analysis , logs , see the
SCAL and RCAL
Routine Core Analysis Special CoreAnalysis
29
Basic Rock Properties
30. 1-Porosity:
is defined as the ratio of pore volume to total rock volume:
Where :
Vp = pore space volume
Vb = bulk volume
Porosity Measurements :Porosity is measured in two ways :
1. from wire line logs
2. Laboratory measurement on core
1-Porosity from wire line logging :
Porosity can be estimated from interpretation of wire line logs, in particular
Acoustic ( sonic) , neutron, Density & NMR logs.
30
Basic Rock Properties
31. 2-Porosity Laboratory measurement on core:
Porosity is calculated using the following equation:
Where :
Vp : pore space volume
Vm : matrix (solid rock) volume
Vb : bulk volume (Vp + Vm)
Bulk volume (Vb) can be determined directly from core dimensions
if we have a fluid-saturated regularly shaped core (normally cylindrical),
or by fluid displacement methods by weight where the density of the
solid matrix and the displacing fluid is known, or directly by volume
displacement.
Matrix volume (Vm) can be calculated from the mass of a dry sample
divided by the matrix density. It is also possible to crush the dry solid and
measure its volume by displacement, but this will give total porosity rather
than effective (interconnected) porosity.
31
Basic Rock Properties
32. Boyle’s law : used to calculate the
matrix volume present in the
second
cell using Boyle’s law .This method
can be very accurate, especially
for low-porosity rock.
Boyle’s law: P1V1 = P2V2
(assuming gas deviation factor Z
can be
ignored at relatively low pressures)
can now be used.
Pore space volume (Vp) can also
be determined using gas
expansion
methods.
Basic Rock Properties
32
33. 2-Permeability :
Permeability: Is the property a rock has to transmit fluids. It is related to
porosity but is not always dependent upon it. Permeability is controlled by the
size of the connecting passages (pore throats or capillaries) between pores. It
is measured in darcies or milli-darcies
absolute permeability : the ability of a rock to transmit a single fluid when it is
100% saturated with that fluid
Effective permeability : refers to the presence of two fluids in a rock, and is the
ability of the rock to transmit a fluid in the presence of another fluid when the
two fluids are immiscible
Relative permeability : is the ratio between effective permeability of fluid at
partial saturation, and the permeability at 100% saturation (absolute
permeability).
33
Basic Rock Properties
34. relative permeability
To account for the effect of multiple fluids,
relative permeability's are defined as follows:
Water oil relative permeability
Typical relative permeability curves for oil
and water are shown in Figure Oil
permeability decreases monotically from its
maximum at the irreducible water saturation,
krowe, to zero at the residual oil saturation to
water. Water permeability increases
monotonically from zero at the irreducible
water saturation to a maximum at the
residual oil saturation, krwe.
Typical water- oil relative permeability curves.
34
Basic Rock Properties
35. relative permeability
Gas-oil relative permeability
Gas-oil permeabilities are usually
measured in samples presaturated
with water so that irreducible water
is present in the sample as it would
be in the reservoir. The relative
permeabilities of oil and gas are
plotted against either liquid (oil plus
water)
Typical Gas- oil relative permeability curves.
Basic Rock Properties
35
36. Measurement of Relative Permeability
There are two ways of measuring relative permeabilities in the laboratory.
1. Steady-state methods.
2. Unsteady-state methods.
Steady-state methods involve the simultaneous injection of two or more
phases into a core of porous material. The flow ratio is fixed, and the test
proceeds until an equilibrium is reached such that the pressure drop across
the core has stabilized. The data obtained are used with Darcy’s law to
calculate the relative permeabilities of each phase. The flow ratio is changed
to give relative permeabilities over the full range of saturations.
The advantage of steady-state methods is that it is simple to interpret
resulting data. It is, however, time-consuming since a steady state can take
many hours to achieve.
Unsteady-state methods are an indirect technique in which the relative
permeabilities are determined from the results of a simple displacement test.
Flow-rate data for each phase are obtained from the point at which the
injected phase breaks through and we have two-phase flow
36
Basic Rock Properties
37. Measurement of Permeability :
1. From Core (Laboratory Determination of Permeability)
2. Well test
3. Darcy’s Law in Field Units
4. Formation tester
5. From log and NMR log
37
Vertical and Horizontal Permeability :
It is normally (but not always) assumed that horizontal permeability is the
same in each direction; but vertical permeability is often, and particularly in
clastics, significantly smaller than horizontal permeability when sediments
are frequently poorly sorted, angular, and irregular. Vertical/horizontal
(kv/kh) values are typically in the range 0.01- 0.1.
Basic Rock Properties
38. Measurement of Permeability :
1. From Core (Laboratory Determination of Permeability)
Laboratory Determination of Permeability Single-phase absolute permeability is
measured on core in a steel cylinder where pressures P1 and P2 are measured
for a given gas flow rate Q.
For a gas: from Darcy’s law for
horizontal flow,
For an incompressible liquid: for
horizontal flow
Where : Q : volumetric flow rate (cm3/s); A : area (cm2); m : viscosity of
the gas or liquid; P : pressure (atmospheres); x : length of core (cm). This
gives the value for permeability k in Darcy’s equation.
38
Basic Rock Properties
39. For a constant production flow rate Q,
permeability can be estimated from
average formation thickness h, fluid
viscosity m, bottom hole pressure Pw,
initial reservoir pressure Pe at an
assumed undisturbed (still at initial
conditions) distance re from the well
and wellbore radius rw using the
equations.
Measurement of Permeability :
2-Permeability From Well-Test
Analysis
Basic Rock Properties
39
40. Where :
k is in milli-Darcies (mD);
u is in RB/day/ft2;
dx dp is in psi/ft;
m is in centipoise (cP);
Y is specific gravity (dimensionless)
Measurement of Permeability :
3- from Darcy’s Law in Field Units
In field units the Darcy equation will be
Basic Rock Properties
40
41. interfacial energy between oil and solid (dyne/cm)
interfacial energy between water and solid (dyne/cm)
interfacial energy, or IFT, between oil and water (dyne/cm)
contact angle at oil–water–solid interface measured through the water phase(degrees)
3-Wettability
Wettability is the ability of a fluid phase to wet a solid surface preferentially in the
presence of a second immiscible phase. The wetting, or wettability, condition in a
rock–fluid system depends on IFT. Changing the type of rock or fluid can change
IFT and hence the wettability of the system. Adding a chemical such as
surfactant,
polymer, corrosion inhibitor, or scale inhibitor can alter wettability.
Wettability is measured by contact angle, which is always measured through the
denser phase and is related to interfacial energies by
Basic Rock Properties
41
42. Wettability
Contact angles for oil-wet and water-wet examples are illustrated in Figure
(A)
Wettability is usually measured in the laboratory. Table (--) presents
examples
of contact angles for different wetting conditions. Several factors can affect
laboratory measurements of wettability. Wettability can be changed by
contact of the core during coring with drilling fluids or fluids on the rig floor,
and by contact of the core during core handling with oxygen or water from the
atmosphere. Laboratory fluids should also be at reservoir conditions to obtain
the most reliable measurements of wettability.
Basic Rock Properties
Figure (A)
Table ( --)
42
43. Special Core Analysis
Core measurements include
imbibition and centrifuge
capillary pressure measurements
An Amott imbibition test
compares the spontaneous
imbibition of oil and water to the
total saturation change obtained
by flooding. We will also see later
pressure and
permeability
give an idea of
that capillary
relative
measurements
rock wettability
Measuring Wettability
Several methods are available to
measure a reservoir’s wetting
preference.
Basic Rock Properties
43
44. Where:
Sw : water saturation
So : oil saturation
Sg : gas saturation
4-Saturation
Saturation is the proportion of
interconnected pore space
occupied by a given phase. For
a gas –oil-water system
Routine Core Analysis
Basic Rock Properties
44
45. Where :
Pc : capillary pressure (psi)
Pnw : pressure in non-wetting phase (psi)
Pw : pressure in wetting phase (psi)
5-Capillary Pressure
Capillary pressure is the pressure difference across the curved interface
formed by two immiscible fluids in a small capillary tube. The pressure
difference is
Basic Rock Properties
45
46. Where :
Po :pressure in the oil phase (psia)
Pw : pressure in the water phase (psia)
Capillary pressure increases with height above the oil–water contact (OWC)
as
water saturation decreases.
Oil–Water Capillary Pressure
Oil is the non-wetting phase in a water-wet oil–water reservoir. Capillary
pressure
for an oil–water system is
Basic Rock Properties
46
47. Where :
Pg : pressure in the gas phase (psia)
Po : pressure in the oil phase (psia)
Capillary pressure increases with height above the gas–oil contact (GOC) as
the
wetting phase saturation decreases.
Gas–Oil Capillary Pressure
In gas–oil systems, gas usually behaves as the non-wetting phase, and oil is
the
wetting phase. Capillary pressure between oil and gas in such a system is
Basic Rock Properties
47
48. Capillary Pressure measurement
Can estimate the Capillary
pressure from special core
analysis ,
Capillary pressure is usually
determined in the laboratory by
centrifuge experiments
that provide a relationship
between capillary pressure Pc
and water saturation Sw. A typical
Pc versus Sw curve has the
following features
Basic Rock Properties
48
49. Reservoir Fluid Properties can Estimated from PVT sample
• Oil Compressibility
• Saturation Pressure
• Live Oil Viscosity
• Live Oil Density
• Oil Formation Volume Factor
• Gas-Oil Ratio
• Liberated Gas Formation Volume factor
• Incremental Liberated Gas-Gravity
• Cumulative liberated Gas-Gravity
49
Basic Fluid Properties
50. • Types of fluid Sampling
(1)Sub-surface sampling (Down-hole sampling)
1-DST strings
2 Wireline sample ( MDT – in open hole )
3 Slickline ( cased hole )
(2)Surface sampling
1-Wellhead samples
2-Separator samples
Sub-surface sampling for Oil Reservoirs Subsurface
samples are generally taken with the well shut-in.
The sample should be taken under single-phase
conditions, Pres > Pb The well should be fully
cleaned up A static pressure gradient survey should
be performed either prior to or during sampling to
check for the presence of water at the bottom of the
well
Basic Fluid Properties
50
51. Surface sampling for Oil/gas Reservoirs Sampling at the wellhead Valid
fluid samples are only likely to be obtained if the fluid is single-phase at
the wellhead Poses safety hazards (high-pressure fluid...) Sampling at
the separator Easier, safer, cheaper Only reliable surface method if fluid
is two-phase at the wellhead
Wellhead sampling Sample point should be as near wellhead as possible
Separator sampling The most important factor in separator sampling is
stability of conditions Stabilized gas and oil flow rates (and therefore
GOR) Stabilized temperature Stabilized wellhead pressure Gas and
liquid samples should be taken simultaneously, as they are a matched
pair Oil and gas rates must be measured carefully Sample points must
be as close to the separator as possible
51
Basic Fluid Properties
53. The following terms are defined for the black oil model:
Bo :oil formation volume factor (rb/stb or m3/scm)
= the ratio of oil volume at reservoir conditions to the oil volumeat
surface conditions
Rs : solution gas-oil ratio ratio (SCF=stb or scm=scm)
= the ratio of the standard volume of solution gas dissolved inthe
oil at a given pressure to the oil volume at surfaceconditions
Bg : gas formation volume factor (rb=SCF or m3/scm)
= the ratio of gas volume at a reservoir conditions to thegas
volume at surface conditions
Bw : water formation volume factor (rb=stb or m3/scm)
= the ratio of water volume at reservoir conditions to thewater
volume at surface conditions
Basic Fluid Properties
53
54. Bubble point pressure (pb)
Bubble point pressure (pb) is the Pressure at which first bubble of gas is released from
reservoir oils
Gas oil ratio (GOR)
Gas oil ratio (GOR)=total associated gas (SCF) / total crude production (STB) @ 60 f, 14.7
psi
Shrinkage factor (SF)
Shrinkage factor (SF) = Stock tank barrel (STB) / reservoir fluid barrel
Fluid Viscosity (µo,g,w)
Is a measure of a fluid's internal resistance to flow
Fluid viscosity depends on pressure, temperature, and fluid composition.
Typical values:
Oil: 0.2 to 30 cp
Gas: 0.01 to 0.05 cp
Water: 0.5 to 1.05 cp
54
Basic Fluid Properties
58. (5) Reservoir Classifications
1. Clastic Reservoir
2. Carbonate Reservoir
According to fluid properties
According to Rock type
According to phase behavior
According to drive mechanism
1. Black oil
2. Volatile Oil
3. Retrograde condensate gas
4. Wet gas
5. Dry gas
1. Single phase gas
2. Gas condensate
3. Under saturated oil
4. saturated oil
1. Solution gas drive
2. Gas Cup drive
3. Water drive
4. Gravity drainage drive
5. Combination drive
58
59. •The Five Reservoir Fluids
1-According to fluid properties
According to fluid properties
1. Black oil
2. Volatile Oil
3. Retrograde condensate gas
4. Wet gas
5. Dry gas
59
60. Black Oil Reservoirs:
•GOR < 1,000 SCF/STB
•Density less than 45° API
•Reservoir temperatures < 250°F
•Oil FVF < 2.00 (low shrinkage
oils)
•Dark green to black in color
•C7+ composition > 30%
60
Black Oil Reservoirs:
61. Volatile Oil Reservoirs:
•1,000 < GOR < 8,000 SCF/STB
•Density between 45-60° API
•Oil FVF > 2.00 (high shrinkage
oils)
•Light brown to green in color
•C7+ composition > 12.5%
Volatile Oil Reservoirs:
61
62. Gas Condensate Reservoirs:
•70,000 < GOR < 100,000
SCF/STB
•Density greater than 60° API
•Light in colour
•C7+ composition < 12.5%
Gas Condensate Reservoirs:
62
63. Wet Gas Reservoirs:
•GOR > 100,000 SCF/STB
•No liquid is formed in the reservoir.
•Separator conditions lie within
phase envelope and liquid is
produced at surface.
Wet Gas Reservoirs:
63
64. Dry Gas Reservoirs:
•GOR > 100,000 SCF/STB
•No liquid produced at surface
Dry Gas Reservoirs:
64
66. 2-According to Rock type
66
Reservoir must be ( porous , permeable & Trapped )
Any reservoir and formation should know the petro-physical
properties :
1. Porosity
2. Permeability
3. Wettability
4. Saturation
5. Capillary Pressure
petro-physical properties can calculated from :
1. Well logging
2. Core
3. Well test
67. 1. Clastic Reservoir
2. Carbonate Reservoir
According to Rock type
2-According to Rock type
67
1-Clastic Reservoir
• Consist primarily of Silicate Mineral ( Quartz SiO2)
• Sandstone porosity ( 10-30 )%
2-Carbonate Reservoir
• Mean limestone and dolomite
• Limestone is better than dolomite for ( porosity and permeability )
69. According to phase behavior
1. Single phase gas
2. Gas condensate
3. Under saturatedoil
4. saturated oil
3-According to phase behavior
69
70. Pressure-temperature phase diagram
for
multicomponent hydrocarbon reservoir
fluid mixture. For
isothermal production in the reservoir:
position Aindicates
reservoir fluid found as an under
saturated oil;
position B
indicates reservoir fluid found as a gas
condensate;
position C indicates reservoir fluid
found as a dry gas
70
Pressure-temperature phase diagram
71. 4-According to drive mechanism
According to drive mechanism
1. Solution gas drive
2. Gas Cup drive
3. Water drive
4. Gravity drainage drive
5. Combination drive
Drive Mechanism
The natural energy of the reservoir used to transport hydrocarbons towards and out of the
production wells
.
There are five important drive mechanisms (or combinations).
1. Solution Gas Drive.
2. Gas Cap Drive.
3. Water Drive.
4. Gravity Drainage.
5. Combination or Mixed Drive
A combination or mixed drive occurs when any of the first three drives operate together
or when any of the first three drives operate with the aid of gravity drainage.
71
72. 1- Solution Gas Drive
Solution Gas Drive:
Gas breaks out of solution and
expanding gas maintains pressure
in reservoir somewhat over time
72
Characteristics Trend
Reservoir Pressure Declines rapidly and continuously
Gas/Oil Ratio First low then rises to a maximum and then drops
Production Rate continues to decline First high, then decreases rapidlyand
Water Production None
Well Behavior Requires artificial lift at early stages
Expected Oil Recovery 5-30% of original oil-in-place
73. Gas Cap Drive:
Gas in gas cap is expanding as pressure
depletes, maintaining pressure somewhat
overtime (later stages of solution gas drive)
73
2.Gas cap Drive.
Characteristics Trend
Reservoir Pressure Falls slowly and continuously
Gas/Oil Ratio Rises continuously
Production Rate First high, then declines gradually
Water Production Absent or negligible
Well Behavior Cap Long flowing life depending on size of gas cap
Expected Oil
Recovery
20 to 40% of original oil-in-place
74. .
Water Drive
Large aquifer volume expands
providing pressure for relatively
small oil volume. Can be
supplemented with water injection
Over time:
3.Water Drive.
Characteristics Trend
Reservoir Pressure Remains high
Gas/Oil Ratio Remains steady
Water Production tarts early and increases to appreciable amounts
Well Behavior Cap Flow until water production gets excessive
Expected Oil
Recovery
up to 60% original oil-in-place.
74
75. Gravity Drainage Drive
Usually for heavy oils with very little or no
gas.
Oil literally is produced as the density of the
oil drops and oil moves under force of
gravity.
Normally accompanied by artificial lift.
Can also be supplemented with water
injection.
Over Time:
Reservoir pressure remains low.
GORvery low if at all.
75
4.Gravity Drainage.
76. 5.Combination or Mixed Drive
76
5.Combination or Mixed Drive
combination drives : we have a gas cap
with the oil accumulation underlain
by water providing potential water drive
.So both free gas and water are in
contact with the oil.
In such a reservoir some of the energy
will come from the expansion of the gas
and some from the energy within the
massive supporting aquifer and it is
associated compressibility.
77. Reservoir Drive Indexes from the Material Balance Equation (MBE)
A general Material Balance Equation that can be applied to all reservoir types was
first developed in 1936. Although it is a tank model equation, it can provide great
insight for the practicing reservoir engineer.
Reservoir Drive Indexes from the Material Balance Equation (MBE)
77
79. (6) Determined hydrocarbon in place
79
Five methods to Determined hydrocarbon in place :
1. Analogy Method
2. Volumetric method
3. Material Balance Method
4. Decline curve analysis Method
5. Reservoir simulation Method
80. (6) Determined hydrocarbon in place
1 Analogy method
The analogy method is applied by comparing factors for the analogous and
current fields or wells. A close-to-abandonment analogous field is taken as
an approximate to the current field. This method is most useful when running
the economics on the current field; which is supposed to be an exploratory
field.
2 Volumetric method
The volumetric method, on the other hand, entails determining the areal
extent
of the reservoir, the rock pore volume, and the fluid content within the pore
volume. This provides an estimate of the amount of hydrocarbons-in-place.
The
ultimate recovery, then, can be estimated by using an appropriate recovery
factor.
Each of the factors used in the calculation above have inherent
uncertainties that, when combined, cause significant uncertainties in the
reserves estimate. 80
81. Volume of Oil Initially In Place (OIIP)
To estimate oil initially volume in place, the following formula is a
volumetric calculation for oil.
Where;
STOIIP = stock tank oil in place, stb
A= area, acre
h = reservoir thickness, ft
ɸ
= rock porosity, %
Swc =connate water saturation, %
Boi = oil formation volume factor, rb/stb
Note: the stock tank condition is a standard surface condition of oil and
gas at 60F and 14.7 psia.
(6) Determined hydrocarbon in place
81
82. Volume of Gas Initially In Place (GIIP)
The formula to determine gas in place is listed below;
Where;
G = gas oil in place at standard condition, scf
A= area, acre
h = reservoir thickness, ft
ɸ
= rock porosity, %
Swc =connate water saturation, %
Bgi = gas formation volume factor, rcf/scf
Note: This is the same formula as the oil in place but only constant is
different because of volume of gas is reported in cu-ft.
(6) Determined hydrocarbon in place
82
83. (6) Determined hydrocarbon in place
3-Material balance calculation
is an excellent tool for estimating
gas reserves. If a reservoir
comprises a closed system and
contains single-phase gas, the
pressure in the reservoir will
decline proportionately to the
amount of gas produced.
Unfortunately, sometimes bottom
water drive in gas reservoirs
contributes to the depletion
mechanism, altering the
performance of the non-ideal gas
law in the reservoir. Under these
conditions, optimistic reserves
estimates can result.
83
84. (6) Determined hydrocarbon in place
84
4-decline analysis and material balance
As production and pressure data from a field become available, decline analysis
and material balance calculations, become the predominant methods of calculating
reserves. These methods greatly reduce the uncertainty in reserves estimates.
Decline curve relationships are empirical, and rely on uniform, lengthy production
periods. It is more suited to oil wells, which are usually produced against fixed bottom-
hole pressures. In gas wells, however, wellhead back-pressures usually fluctuate,
causing varying production trends and therefore, not as reliable .
The most common decline curve relationship is the constant percentage decline
(exponential). With more and more low productivity wells coming on stream, there
is currently a swing toward decline rates proportional to production rates
(hyperbolic and harmonic). Although some wells exhibit these trends, hyperbolic or
harmonic decline extrapolations should only be used for these specific cases. Overe-
xuberance in the use of hyperbolic or harmonic relationships can result in
excessive reserves estimates
.
87. EOR methods : used to improve reservoir recovery efficiency, and explain
their differences For each method, state whether it can improve
displacement, vertical or areal sweep efficiency and explain how it works.
1 Primary recovery
Primary recovery, using ( the natural energy of reservoirs and artificial lift ) ,
typically recovers up to 50% of OOIP (average 19%).
2 Secondary recovery
Secondary recovery involves adding energy to the natural system by
injecting water to maintain pressure and displace oil (also known as water
flood). Typical recoveries are 30-50% of OIP after primary recovery (average
32%).
3 Tertiary recovery
Tertiary recovery includes all other methods used to increase the amount of
oil recovered ( thermal , gas injection , chemical injection , others ) . Typical
recoveries are more than 50% of OIP .
87
What is the (EOR) ?
88. The goal of any enhanced oil recovery process is to mobilize "remaining" oil.
This is achieved by enhancing oil displacement and volumetric sweep
efficiencies.
Oil displacement efficiency is improved by reducing oil viscosity (e.g.,
thermal floods) or by reducing capillary forces or interfacial tension (e.g.,
miscible floods).
Volumetric sweep efficiency is improved by developing a more favorable
mobility ratio between the injection and the remaining oil-in-place (e.g.,
polymer floods, water alternating- gas processes).
It is important to identify remaining oil and the mechanisms that are
necessary to improve recovery prior to implementing an EOR process.
88
Objective of EOR
89. Water-flooding : use water
Thermal methods: steam stimulation, steam-flooding, hot water drive, and
in- situ combustion
Chemical methods: polymer, surfactant, caustic, and micellar/polymer
flooding
Miscible methods: hydrocarbon gas, CO2, and nitrogen (flue gas and
partial miscible/immiscible gas injection may also be considered)
EOR methods
89
90. Description
Water-flooding consists of injecting water into the reservoir. Most widely used
post-primary recovery method. Water is injected in patterns or along the
periphery of the reservoir.
Mechanisms that Improve Recovery Efficiency
• Water drive
• Increased pressure
Limitations
• High oil viscosities result in higher mobility ratios.
• Some heterogeneity is acceptable but avoid extensive fractures.
Challenges
• Poor compatibility between the injected water and reservoir may cause
formation damage
Water-flooding
90
92. To increase ultimate oil production beyond that achievable with primary and
secondary methods, there are a few steps to undertake.
1. First, an improvement of the sweep efficiency must ensue.
2. This is then followed by a reduction of the amount of residual oil in the
swept zone.
3. Thirdly, there must be an increase in the displacement efficiency.
4. And finally, there must be a reduction in the viscosity of thick oils.
Here will explain :
1. Surfactant / Polymer Flooding
2. Polymer Flooding
92
Chemical oil recovery methods
93. Surfactant / Polymer Flooding
93
Description
Surfactant / polymer flooding consists of injecting slug that contains water,
surfactant, electrolyte (salt), usually a co-solvent (alcohol), followed by
polymer-thickened water.
Mechanisms that Improve Recovery Efficiency
• Interfacial tension reduction (improves displacement sweep efficiency).
• Mobility control (improves volumetric sweep efficiency).
Limitations
• An areal sweep of more than 50% for water-flood is desired.
• Relatively homogeneous formation.
• High amounts of anhydrite, gypsum, or clays are undesirable.
94. Challenges
• Complex and expensive system.
• Possibility of chromatographic
separation of chemicals.
• High adsorption of surfactant.
• Interactions between surfactant
and polymer.
• Degradation of chemicals at high
temperature.
Surfactant / Polymer Flooding
94
95. Polymer Flooding
95
Description
Polymer augmented waterflooding consists of adding water soluble polymers
to the water before it is injected into the reservoir.
Mechanisms that Improve Recovery Efficiency
• Mobility control (improves volumetric sweep efficiency).
Limitations
• High oil viscosities require a higher polymer concentration.
• Results are normally better if the polymer flood is started before the water-
oil ratio becomes excessively high.
• Clays increase polymer adsorption.
• Some heterogeneity is acceptable, but avoid extensive fractures.
96. Challenges
• Lower injectivity than with water
can adversely affect oil
production rates in the early
stages of the polymer flood.
• Xanthan gum polymers cost
more, are subject to microbial
degradation, and have a greater
potential for wellbore plugging.
Polymer Flooding
96
97. Miscible Gas Flooding ( CO2 injection )
97
Description
CO2 flooding consists of injecting large quantities of CO2 (15% or more
hydrocarbon pore volumes) in the reservoir to form a miscible flood.
Mechanisms that Improve Recovery Efficiency
• Components from the oil, and, if the pressure is high enough, develops
miscibility to displace oil from the reservoir.
• Viscosity reduction / oil swelling.
Limitations
• Very low viscosity of CO2 results in poor mobility control.
• Availability of CO2
• Surface facilities
98. Challenges
• Early breakthrough of CO2
causes problems.
• Corrosion in the producing wells.
• The necessity of separating CO2
from saleable hydrocarbons.
Repressuring of CO2 for
recycling.
• A large requirement of CO2 per
incremental barrel produced.
Miscible Gas Flooding ( CO2 injection )
98
99. Miscible Gas Flooding (Hydrocarbon Injection)
99
Description
Hydrocarbon gas flooding consists of injecting light hydrocarbons through the
reservoir to form a miscible flood.
Mechanisms that Improve Recovery Efficiency
• Viscosity reduction / oil swelling / condensing or vaporizing gas drive.
Limitations
• Minimum depth is set by the pressure needed to maintain the generated
miscibility. The required pressure ranges from about 1,200-5000 psi for the
high pressure Gas Drive, depending on the oil.
• A steeply dipping formation is very desirable- permits gravity stabilization of
the displacement that normally has an unfavorable mobility ratio.
100. Challenges
• Viscous fingering results in poor
vertical and horizontal sweep
efficiency.
• Large quantities of expensive
products are required.
• Solvent may be trapped and not
recovered
Miscible Gas Flooding (Hydrocarbon Injection)
100
101. Nitrogen / Flue Gas Flooding
101
Description
Nitrogen or flue gas injection consists of injecting large quantities of gas that
may be miscible or immiscible depending on the pressure and oil composition.
Large volumes may be injected, because of the low cost.
Nitrogen or flue gas are also considered use as chase gases in the
hydrocarbon-miscible and CO2 floods.
Mechanisms that Improve Recovery Efficiency
• Vaporizes the lighter components of the crude oil and generates miscibility
if the pressure is high enough.
• Provides a gas drive where a significant portion of the reservoir volume is
filled with low-cost gases.
Limitations
• Miscibility can only be achieved with light oils at high pressures; therefore,
deep reservoirs are needed.
• A steeply dipping reservoir is desired to permit gravity stabilization of the
displacement, which has a very unfavorable mobility ratio.
102. Challenges
• Viscous fingering results in poor
vertical and horizontal sweep
efficiency.
• Flue gas injection can cause
corrosion.
• Non hydrocarbon gases must be
separated from saleable gas
Nitrogen / Flue Gas Flooding
102
103. Thermal (Steam-flooding)
103
Description
Steam-flooding consists of injecting about 80% quality steam to displace oil.
Normal practice is to precede and accompany the steam drive by a cyclic
steam simulation of the producing wells (called Huff and Puff).
Mechanisms that Improve Recovery Efficiency
• Viscosity reduction / steam distillation.
• Thermal expansion.
• Supplies pressure to drive oil to the producing well.
Limitations
• Application to viscous oil in massive, high permeability sandstones or
unconsolidated sands.
• Oil saturations must be high, and pay zones should be > 20 feet thick to
minimize heat losses to adjacent formations.
• Steam-flooded reservoirs should be as shallow as possible, because of
excessive wellbore heat losses.
104. Thermal (Steam-flooding)
More Limitations
• Steam-flooding is not normally done in
carbonate reservoirs.
• Since about 1/3 of the additional oil
recovered is consumed to generate the
required steam, the cost per
incremental barrel of oil is high.
• A low percentage of water-sensitive
clays is desired for good injectivity
Challenges
Adverse mobility ratio and channeling of
steam.
104
105. Thermal (In SITU COMBUSTION) or "Fire-flooding")
Description
This method is sometimes applied to reservoirs containing oil too viscous or
"heavy" to be produced by conventional means. Burning some of the oil in situ
(in place), creates a combustion zone that moves through the formation toward
production wells, providing a steam drive and an intense gas drive for the
recovery of oil.
105
108. (8) Reservoir Surveillance
108
A definition of surveillance
A definition of surveillance that is more suitable for managing hydrocarbon
assets is the : ( continuous process of generating opportunities for improving
reservoir performance )
History of Reservoir Surveillance
Surveillance techniques were first discussed in the SPE literature in the early
1960s . Since then, reference to surveillance has been made, but mostly in the
context of episodic data gathering to monitor performance, primarily in flooding
situations
The four stages of value creation using measurements, in order of increasing
benefits, are
1. Data
2. Information
3. Knowledge
4. Intelligence
109. (8) Reservoir Surveillance
these stages along with the
characteristics pertaining to each
stage. Significant increase in
effort is required for large gains in
value as the information is
converted to knowledge and then
into intelligence. Intelligence is
gained when we possess the
ability to predict the future for a
parameter, property, or system.
The rapidity with which
companies gain system
intelligence differentiates and
distinguishes them from their
competitors
109
112. Example 1 : plan to identify thief zones and remediate:
112
Example 1 : plan to identify thief zones and remediate:
Steps :
1. Develop areal distribution maps of movable oil in place.
2. Based on production/injection data, prepare well connectivity maps.
3. Run injection and production profile surveys.
4. Use petrophysical data, injection surveys, and connectivity maps to identify
correlatable thief zones.
5. Plan appropriate data gathering.
6. Evaluate alternatives for shutoff including production curtailment,
debottlenecking, pattern realignment, and facilities upgrade.
113. Uncertainty management plans (UMP)
the uncertainty about the reservoir, its performance, our ability to forecast, and
new opportunities to improve recovery that makes surveillance so challenging.
During early phases of field development, there are significant uncertainties that
lead to project risks.This Fig. show how uncertainty-management plan sresult in
the definition of technology and surveillance plans for an asset.
Uncertainty management plans (UMP) drive surveillance and technologyplans
113
114. Performance expectations
114
Performance expectations must be established for all major components of
an asset. This includes wells, reservoirs, fields, equipment, and facility
installations. Defining performance goals and expectations for the assets
provides a valuable basis for future comparison and analysis. Minimum
expectations for asset management include compilation and active
management of the following data streams:
1. Geological maps for the fields including structure maps, isopach maps,
and well-record maps.
2. Mechanical well sketch for each of the wells including tubing and casing
detail as well as wellhead data and other tubing equipment (packers,
liners, nipples, plug back total depth, subsurface safety valves, gas-lift
valve depths, pump depths, etc.).
3. A petrophysical summary for each well that includes formation tops, pay
intervals, net feet of pay, and sand-identification information.
115. Performance expectations
4. An evaluated open-hole log over the entire logged interval.
5. Raw and allocated production data and allocation factors.
6. Rock property data, core data and core-study data, and rock failure data.
7.Fluid properties and pressure-volume-temperature analyses for the wells
and reservoirs.
8. Pressure data—static and buildup from all surveys taken in the field.
9. Authority for expenditure (containing detailed justifications) for each well.
10. Well summary sheet with well histories.
11.Copy of field studies, petrophysical studies, reservoir and geological
studies.
12. Reserve report data.
115
13. Facility, plant, process flow diagram (PFD), flowline data and drawings.
116. data types, roles, and primary responsibilities
shows an example of a table that may be used to assign data ownership and
responsibility for different sources of information. Such tables are valuable in
the dynamic personnel situation in most companies.
116
117. parameter for Static and Dynamic Reservoir Information
simple matrix chart that allows one to identify which measurements provide
information for a given parameter for Static Reservoir Information and Dynamic
Reservoir Information
117
118. This table shows how the
state of knowledge for a
given parameter will
change as a result of using
a particular measurement
technique . This tells us
which method will reduce
the uncertainty in a given
parameter the most
118
119. This table is constructed with
categorical variables (low,
medium, high). However,
numerical values can
be assigned and then
vertically summed by
columns to establish the
highest value in terms of
uncertainty resolution by a specific tool. Although the table looks relatively
innocuous, a number of considerations are required to populate the low, mid,
high nature of a particular measurement . The consideration should include
• Resolution
•Accuracy
•Repeatability
•Interpretability
•Environment variables that impact tool fidelity 119
134. (9) Tracer Techniques used for Reservoir surveillance.
134
The technologies have existed for over 50 years.
Tracers provide a powerful surveillance technique for understanding reservoir
connectivity and determining remaining oil saturation. Success of secondary and
tertiary oil recovery projects targeting remaining oil in mature or partially
depleted reservoirs strongly depends on appropriate description of reservoir
heterogeneity and remaining oil distribution. Tracers have been used in
groundwater hydrology and chemical industry for a very long time. Applications
in the oil industry have been mixed.
Two types of tracer tests are generally conducted:
1. Single-well tracer tests
2. Inter-well tracer tests
135. 1-Single-well tracer tests
Use of single-well tracer tests is widespread. Tracers can be used for estimation
of oil saturation in the vicinity of the wells, determining injection profiles of fluids,
tagged tracer for cement and proppants can be run in a well to determine the
effectiveness of fracture proppant placement or cement quality behind pipe. With
increased use of single-trip, multistage fracturing operations both in
unconventional reservoirs and thick deep water reservoirs, tagged tracers are
being used more often for understanding the quality of completion, proppant
placement, and cement isolation. A more recent development is the use of tracer
cartridges that can be placed in between flowing intervals in production wells.
The tracers are soluble only in water phase and can help determine which
intervals are producing water without the introduction of wireline tools to run
PLTs.
135
(9) Tracer Techniques used for Reservoir surveillance.
136. 2-Inter-well tracer tests
Inter-well tracer tests, if designed and conducted well, can be a powerful tool for
describing a reservoir, investigating unexpected anomalies in flow, verifying
suspected flow barriers, and determining reservoir heterogeneity including
layering. Tracers are also used for determining connectivity between wells,
determining remaining oil saturation and estimating performance of a water-
flood, solvent injection, or steam injection
Common Use of tracers in reservoir managements
1. Determine remaining/residual oil saturation
2. Define well-to-well connectivities
3. Determine the presence of flow barriers
4. Characterize reservoir heterogeneity and layering
5. Compute swept pore volume
6. Assess cement integrity in wellbores
7. Evaluate completion quality and proppant placement
8. Calculate phase dispersivities
136
(9) Tracer Techniques used for Reservoir surveillance.
137. Tracer Characteristics
A perfect tracer for subsurface reservoir application should have the following
characteristics:
1. Soluble and move at the same speed as the tracer carrier
2. Stable except for radioactive tracer that decay according to their half lives
3. Not absorbed significantly or broken down by chemicals in target formation
4. Should be at negligible or low concentrations in the reservoir (background)
5. Detectable and measurable at low concentrations
6. Cost efficient
7. Safe to inject, produce, and handle
8. Repeatable and standardized analytical equipment for measurement
137
(9) Tracer Techniques used for Reservoir surveillance.
138. For radioactive tracers, operational safety is the most critical component of
running a tracer program and appropriate attention needs to be paid. From an
operational perspective, overall cost and detectability are important. The
success of a tracer test and its quantitative use is determined by maintaining
material balance in the reservoir. To achieve this, measures should be taken
during tracer selection to make appropriate trade-offs in terms of chemical types,
their dynamic characteristics, and interactions with rocks and fluids.
Tracer Types
(9) Tracer Techniques used for Reservoir surveillance.
138
139. Commonly Used Tracers in the oilfields
(9) Tracer Techniques used for Reservoir surveillance.
139
140. Design Considerations.
The generic questions that should be answered are:
1. What are the objectives of the test (reservoir characterization, proppant
placement determination, injection distribution in a well, residual oil saturation
determination, barrier confirmation, sweep efficiency characterization,
breakthrough characteristics, etc.)?
2. Is it a single or a mult-iwell tracer test?
3. What is the impacted reservoir volume (pattern-size, single-well
drainage/injection volume)?
4. What are the feasible tracer types and volumes based on objectives?
5. What are the detectability limits of the selected tracer?
6. What is the maximum permissible tracer concentration?
7. Is the test being designed to answer qualitative connectivity questions or is
quantitative evaluation needed?
8. What is the volume of tracer injection?
140
(9) Tracer Techniques used for Reservoir surveillance.
141. Design Considerations.
9 What are the analytical techniques used to estimate tracer eluent concentration?
10 What would be the sampling frequency and resulting cost?
11Is in-line sampling and analysis practical? What is the trade-off between in-line
sampling installation cost vs. lab measurement?
12Do lab tests need to be conducted to confirm compatibility with reservoir rock,
fluids, and water?
13Do we understand the adsorption behavior of the tracer in question and the link
to design concentration for detectability?
14 What are the measurement methods and stability of partitioning tracers?
15 Is the partition coefficient constant or do we know the partition coefficient
function for
the tracer?
16What would be the soak and backflow time for single-well partitioning tracer
tests?
17 What are the field equipment requirements for mixing, injection, and sampling
procedures as well as field procedures for handling?
(9) Tracer Techniques used for Reservoir surveillance.
141
144. Reservoir Management
144
Definition of Reservoir Management:
Reservoir Management relies on the use of human, technological and financial
resources to capitalize on profits from a reservoir by optimizing the hydrocarbon
recovery while minimizing both the capital investments and the operating costs.
Main objectives of the reservoir management :
1. Decreasing of the risk
2. Increasing of the oil and gas production
3. Increasing of the oil and gas reserves
4. Minimization of the capital expenditures
5. Minimization of the operating costs
6. Maximizing of the final hydrocarbon recovery
146. Reservoir Management
146
The reservoir management process must be designed and implemented to
individual fields on the basis of:
1. Logistics and size of the field/reservoirs
2. Geological complexity of the field/reservoirs
3. Reservoir rock and fluid properties
4. Depletion state
5. Regulatory controls
The modelling process is based on the following main steps:
1-reconstruction of a reservoir geological model
(geological characterization and fluid properties definition)
2-selection of a reservoir mathematical model
(up-scaling and initialization)
3 calibration of the reservoir geological model
(past history matching)
4 prediction of the reservoir future performance
( production forecasts)
149. Data Acquisition and Characterization
1-Data acquisition :
Data acquisition, involving the gathering of raw data from various sources, i.e.
1. Seismic surveys
2. Well logs
3. Conventional and special core analyses
4. Fluid analyses
5. Static and flowing pressure measurements
6. Pressure-transient tests
7. Periodic well production tests
8. Records of the monthly produced volumes of fluids (oil, gas, and water)
9. Records of the monthly injected volumes of IOR/EOR fluids (water, gas,
CO2, steam, chemicals,…).
149
150. Data Acquisition and Characterization
150
2-Data processing:
Data processing based upon:
1. Seismic time maps
2. Seismic conversion of time-to-depth maps
3. Seismic attribute maps
4. Log analyses
5. Structural maps
6. Cross sections
7. Geologic models
8. Reservoir fluids modeling
9. Simulation models
151. 3-Data integration and Reservoir Characterization
The characterization of a reservoir aims at producing the best detailed
geological reconstruction both of its geometry and of its internal
structure. The overall process is, therefore, the first basic step in the
development of a reservoir model, and it must consider all the available
data, processed and interpreted with the best technologies always
caring to be consistent with the observed historical reservoir
performance.
Geophysical, geological, and engineering characterization provides
also information on the initial distribution of the fluids, as well as on the
hydraulic connectivity between different zones of the reservoir rocks.
151
Data Acquisition and Characterization
152. Data Acquisition and Characterization
The following activities are
normally performed for the
acquisition of the data required by
the reservoir characterization.
1. Seismic
2. Well Logging
3. Core Analysis
4. Fluid Properties
5. Well Testing
152
153. 1-Seismic
Seismic allows reconstructing the
reservoir geological setting through
different level observations:
1. On large scale: reservoir geometry,
identification of main structural
features (e.g. faults), , etc
2. On small scale: detailed structural
and stratigraphycal features, fluid
contacts, etc.
Seismic response of a reservoir
depends on petro-acoustic properties of
the volume of rock investigated; such
properties can be obtained by the
interpretation of specific field data.
153
155. Generally can estimate rock properties from core Analysis
Routine Core Analysis Special CoreAnalysis
155
3- Core analysis
156. Reservoir Fluid Properties can Estimated from PVT sample
• Oil Compressibility
• Saturation Pressure
• Live Oil Viscosity
• Live Oil Density
• Oil Formation Volume Factor
• Gas-Oil Ratio
• Liberated Gas Formation Volume factor
• Incremental Liberated Gas-Gravity
• Cumulative liberated Gas-Gravity
156
4- Fluid Properties
157. Type of well test :
1. Static pressure test
2. Drawdown test
3. Build-up test
4. Injection test / fall-off test
5. Interference test and pulse test
6. Gas well test
7. Flow after flow test,
8. Isochronal test,
9. Modified isochronal test
10. DST
157
5- well test
159. reservoir modeling
Integrated Reservoir Modeling
Static Model
1. Structural modeling
2. Stratigraphic modeling
3. Lithological modeling
4. Petrophysical modeling
159
Dynamic model
1. Up-scaling
2. simulation
3. History matching
160. Static Model
1. Structural modeling
Reconstruction of the geometrical and
structural properties of the reservoir, by
defining a map of its structural top and
the set of faults running through it. This
stage of the work is carried out by
integrating interpretations of the
geophysical surveys with the available
well data.
(I) Static Model
160
161. Static Model
2. Stratigraphic modeling
Definition of a stratigraphic scheme
using well data, which form the basis
for well to well correlations. The data
consist of electrical, acoustic and
radioactive wireline logs, and of results
of core analysis, integrated where
possible with information from
specialist studies and production data.
(I) Static Model
161
162. Static Model
3. Lithological modeling
Definition of the lithological types
(basic facies ), which are characterized
on the basis of lithology,
sedimentology, and petrophysics. This
classification into facies is a
convenient way of representing the
geological characteristics of a
reservoir, especially for the purposes of
subsequent three-dimensional
modeling.
(I) Static Model
162
163. Static Model
4. Petrophysical modeling
A quantitative interpretation of well logs
to determine some of the main
petrophysical characteristics of the
reservoir rock, (porosity, water
saturation, and permeability). Core
data represent the essential basis for
the calibration of interpretative
processes.
(I) Static Model
163
164. Build a Petrel project of the field assembling all the data available :
1-Seismic Interpretation & Inversion
– Horizons and Fault Interpretation
2-Core Description:
– Conceptual depositional model
3- Petrophysical Interpretation
– Data review and QC
– Cementation factor (m), and Saturation exponent (n)
– Permeability-Porosity Transform
– Rock Typing (MICP, RCA, Log Data, Lithofacies)
– Free Water Level and Saturation Height Function
164
(I) Static Model
165. Continue Build a Petrel project of the field assembling all the data
available :
4-Structural modeling
– Fault model, Pillar gridding, Horizon model, Zonation and Layering
5 Facies Modeling
–Population of lithofacies and depositional facies in the 3D Grid
6 Petrophysical Property Modeling
–Realistic property model reflecting the reservoir geological and production
characteristics.
– Stochastic porosity and permeability modeling
– Water saturation modeling
7-Volumetrics Estimation
165
(I) Static Model
170. (II) Dynamic Model
Fully Integrated Petrel Framework
1-Entire model will be based on Petrel
– PVT, SCAL, VFP,Aquifers, Development
Strategies
2Petrel workflows and macros will be used to
ensure a portable and maintainable history
matched model.
3Grid block-independent multipliers will be used:
Zones, Segments, polygones, …This enables a
smooth transition from one grid size to another in
thehistory matching process
170
172. 1-Upscaling
1-Honoring reservoirs heterogeneity
– Retain as much geological details as possible
2-Two Upscaled models:
– High Resolution: Targeted studies (infill drilling, EOR, …)
– Low Resolution: Multi-scenario production forecasts.
– History Matching will take place on the low resolution model first
– Results will then feed into the HM of the high resolution model
3 Understand the continuity of the reservoir properties both areally and vertically
(facies)
4 Preserve vertical barriers
5HCPV maps per zone and porosity cross-sections were made. The final
proposed layering scheme is selected giving priority to zones with high HCPV
and
high vertical contrast of porosity.
(II) Dynamic Model
172
173. Up scaling – QC
1. Check Volumetrics (see separate slide)
2. For all wells compare synthetic porosity, permeability and saturation logs
(fine scale and upscaled models).
3. Perform visual checks on the upscaled porosity and permeability by
comparing 2D map views, 2D cross-sections for the upscaled model and
the static model for all relevant zones.
4. Compare histograms and k-phi cross-plots before and after upscaling for
all the relevant horizons and facies
5. Compare dynamic behavior on a sector model between fine scale and
upscaled models
173
(II) Dynamic Model
174. 2-Reservoir simulation
Reservoir simulation is a branch of petroleum engineering developed for
predicting reservoir performance using computer programs that through
sophisticated algorithms numerically solve the equations governing the complex
physical processes occurring during the production of an oil/gas reservoir.
Basically, a reservoir simulation study involves five steps:
1. Setting objectives
2. Selecting the model and approach
3. Gathering, collecting and preparing the input data
4. Planning the computer runs, in terms of history matching and/or performance
prediction
5. Analyzing, interpreting and reporting the results.
174
(II) Dynamic Model
175. 3-History Matching
1. Uncertainty Analysis: Identify the set of reservoirs parameters with high
uncertainty and their corresponding
2. ranges of uncertainty.
3. Run a sensitivity analysis to investigate the impact of different parameters on
the flow performance (rates, water breakthrough, WCT, GOR, pressure).
4. Narrow down the set of uncertainty parameters to be carried on to be used in
the history matching process.
5. Field, Group & Well level.
6. Production data analysis helps on setting the HM criteria.
7. Calibrate model to well test data.
8. Check quality of the HM using the RST/PNL Data.
9. Potential usage of assisted history matching as applicable (Petrel HM &
Optimization or MEPO).
10. History match the Low Resolution model followed my HM of the High
Resolution model.
(II) Dynamic Model
175
176. Breaks Down Barriers between Disciplines.
Bring the Engineering Models Closer to the Operational World.
Feasibility Validation of Field Development Plans.
Evaluation of any Possible Production System Bottleneck.
Optimizing CAPEX and OPEX
(III) Integrated Asset Model – Surface/Subsurface
176
177. Network Modeling including :
Well/Network Modeling
Well Design and Analysis
Nodal Analysis
Network Debottlenecking
Pipeline & Equipment Sizing
Gas Lift / ESP Optimization
Flow Assurance
Erosion & Corrosion Modeling
Slug flow prediction / Slug
catcher sizing
Field Network Development
Planning
(V) Network Modeling
177
178. Reference
178
1. Reservoir Engineering Handbook, (Tarek Ahmed, 5thedition)
2. integrated Reservoir Asset Management. Principles and Best Practices(John R. Fanchi)
3. Basic of reservoir engineering (ReneCosse)
4. Fundamentals of Applied Reservoir Engineering-Appraisal, Economics-and Optimization
(RICHARD WHEATON)
5. Fundamentals of Reservoir Engineering (L.P. Dake)
6. Reservoir Engineering (Heriot-Watt University)
7. Reservoir Surveillance-(Jitendra Kikani)
8. Reservoir Engineering- the fundamental -simulation and management (Abdus Satter & GhulamM.
Iqbal)
9. Basic Petroleum Geology and Log Analysis – (Hallibuton)
10. Basic Rock and Fluid Properties
11. Larry W . Lake -Petroleum engineering handbook - reservoir engineering andpetro-physics
volume V
12. Reservoir Engineering (Kaiser A. Jasim 2019)
13. method OOIP calculation( paper)
14. Reservoir Management (Dr. Jawad R. RustumAl-Assal)
15. static and dynamic model – work-folw (Kassem Ghorayeb) fromSLB
179. Name: Abbas RadhiAbbas
Position: Chief Engineer / petroleum Engineer
Nationality: Iraq- Missan
Date of Birth: 1978
Gender: Male
Education Background:
Period Education description
1996-2001 University of Bagdad – college of Engineering – petroleum engineering department- (BSc)
Certificates of Appreciation
15 Certificates of Appreciation from difrent international companies such as (Schlumberger- waetherford , CNOOC , COSL ,
BHDC )
Work Experience : in Missan Oil Company ( MOC)
Period Work description
(2004-2006) reservoir engineer
(2006-2010 ) water injection engineer
during (2011) drilling and workover engineer
(2011 to 2020 ) petrophysics manager in Reservoir department
Language:
Mother language:
Arabic
Second
language/level: English/Fluent oral and written in English.
179
About Authorized