Formation evaluation is the process of interpreting measurements taken inside a wellbore to detect and quantify oil and gas reserves. It involves mud logging during drilling, coring to obtain formation samples, open-hole logging before casing, logging while drilling for real-time data, formation testing to obtain fluid samples and pressure measurements, and cased-hole logging after well completion. The data are used to evaluate reservoirs and predict fluid flow for optimal hydrocarbon recovery.
Measurement while drilling (MWD) uses downhole sensors and telemetry systems to provide real-time drilling data. MWD tools use either positive pulse, negative pulse, or continuous wave systems to transmit sensor readings like gamma ray, resistivity, temperature, weight on bit, torque, and turbine RPM to the surface. These sensors help evaluate formation properties, monitor drilling parameters, and conduct directional surveying to steer the well.
This document discusses caliper logs, which measure the size and shape of a borehole. It describes different types of caliper tools, including multi-finger, dual caliper, and ultrasonic caliper tools. The document explains that caliper logs provide information about borehole shape and volume, mud cake buildup, lithology, and cement volume. More arms on a caliper tool provide more accurate measurements of borehole cross-section and shape. Caliper logs are often run with acoustic or neutron-density logs.
The objective of this project is to investigate the measurement methods while drilling a well and perform a general assessment and comparison on the methods.
well logging tools and exercise_dileep p allavarapuknigh7
Logging is a process that provides comprehensive formation information through continuously recording parameter measurements with depth. It plays an important role in exploration and production by obtaining resistivity, porosity, and lithology logs to identify hydrocarbon-bearing zones. Different disciplines like drilling, logging, core analysis, and reservoir modeling are interrelated and provide both open and cased hole data. Logs are interpreted to calculate parameters like water saturation, hydrocarbon saturation, and effective porosity, with the goal of determining hydrocarbon saturation multiplied by effective porosity in reservoir units. Accurate interpretation requires integration of log data with core analysis and rock physics studies.
Well logs can be states as “a recording against depth of any of the characteristics of the rock formations traversed by a measuring apparatus in the well-bore.”
Formation evaluation and well logging are processes used to determine the properties of subsurface reservoirs and identify commercially viable oil and gas fields. Key logging tools developed over time include resistivity logs in the 1920s, dipmeters in the 1940s, gamma ray and neutron logs in the 1940s, sonic logs in the 1950s, density logs in the 1960s, and logging while drilling was introduced, allowing real-time data acquisition. The document provides a historical overview of the development of various openhole well logging tools and techniques.
Gamma rays are high-energy electromagnetic waves emitted spontaneously by radioactive elements like potassium, uranium, and thorium found in rocks. A gamma ray log measures this natural radioactivity to indicate the presence of shale and clay in formations. The log uses a scintillation counter detector in the tool to measure gamma radiation from the formation. Radioactive elements tend to concentrate in shale and clay. Therefore, higher gamma ray readings indicate more shale, while clean formations like sandstone have lower readings. The log can be used to correlate between wells and evaluate shale content.
Measurement while drilling (MWD) uses downhole sensors and telemetry systems to provide real-time drilling data. MWD tools use either positive pulse, negative pulse, or continuous wave systems to transmit sensor readings like gamma ray, resistivity, temperature, weight on bit, torque, and turbine RPM to the surface. These sensors help evaluate formation properties, monitor drilling parameters, and conduct directional surveying to steer the well.
This document discusses caliper logs, which measure the size and shape of a borehole. It describes different types of caliper tools, including multi-finger, dual caliper, and ultrasonic caliper tools. The document explains that caliper logs provide information about borehole shape and volume, mud cake buildup, lithology, and cement volume. More arms on a caliper tool provide more accurate measurements of borehole cross-section and shape. Caliper logs are often run with acoustic or neutron-density logs.
The objective of this project is to investigate the measurement methods while drilling a well and perform a general assessment and comparison on the methods.
well logging tools and exercise_dileep p allavarapuknigh7
Logging is a process that provides comprehensive formation information through continuously recording parameter measurements with depth. It plays an important role in exploration and production by obtaining resistivity, porosity, and lithology logs to identify hydrocarbon-bearing zones. Different disciplines like drilling, logging, core analysis, and reservoir modeling are interrelated and provide both open and cased hole data. Logs are interpreted to calculate parameters like water saturation, hydrocarbon saturation, and effective porosity, with the goal of determining hydrocarbon saturation multiplied by effective porosity in reservoir units. Accurate interpretation requires integration of log data with core analysis and rock physics studies.
Well logs can be states as “a recording against depth of any of the characteristics of the rock formations traversed by a measuring apparatus in the well-bore.”
Formation evaluation and well logging are processes used to determine the properties of subsurface reservoirs and identify commercially viable oil and gas fields. Key logging tools developed over time include resistivity logs in the 1920s, dipmeters in the 1940s, gamma ray and neutron logs in the 1940s, sonic logs in the 1950s, density logs in the 1960s, and logging while drilling was introduced, allowing real-time data acquisition. The document provides a historical overview of the development of various openhole well logging tools and techniques.
Gamma rays are high-energy electromagnetic waves emitted spontaneously by radioactive elements like potassium, uranium, and thorium found in rocks. A gamma ray log measures this natural radioactivity to indicate the presence of shale and clay in formations. The log uses a scintillation counter detector in the tool to measure gamma radiation from the formation. Radioactive elements tend to concentrate in shale and clay. Therefore, higher gamma ray readings indicate more shale, while clean formations like sandstone have lower readings. The log can be used to correlate between wells and evaluate shale content.
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. 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
The document provides information about resistivity logs including:
1. It discusses factors that affect resistivity like salinity, porosity, lithology, and clay content. It also explains the principles and theoretical considerations of resistivity logs.
2. It describes different resistivity tools like focused devices (Laterolog, Dual Laterolog, Spherically Focused Log) and unfocused devices (Normal Log, Lateral Log). It also discusses micro-resistivity devices.
3. The document discusses log characteristics including depth of investigation, bed resolution, and different scales used in resistivity logs. It explains how resistivity logs can be used for lithology identification, correlation, and permeability determination.
Mud logging involves collecting and analyzing drill cuttings and mud properties to interpret lithology and detect hydrocarbon shows. It relies on mud circulation from the mud pump through the drill string and annulus to the shale shaker where cuttings are examined. The mud logger monitors and records drilling parameters and cuttings data to help assess the producibility of formations. However, mud logging becomes less accurate at depths over 3000m where cuttings are mixed and it takes longer for mud to return to the surface.
- 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.
Directional drilling is the process of directing a wellbore along a non-vertical trajectory towards a predetermined target. It involves techniques like whipstocks, jet bits, and downhole motors to gradually build angle in the wellbore. There are three main types of directional well paths: Type I involves continuously building angle to a maximum and then holding; Type II involves building, holding, and dropping the angle; Type III only involves continuously building angle. Survey calculation methods like the average angle method are used to determine the wellbore position between survey points by calculating average inclination and azimuth angles.
This document provides an overview of drilling fluids and their role in drilling operations. It discusses the components and properties of drilling fluids, including continuous and dispersed phases as well as additives. The types of drilling fluids are described, including water-based muds, oil-based muds, gases, and gas-liquid mixtures. The key functions of drilling fluids to support drilling operations are also outlined. The document concludes with discussions of pressure terminologies and examples of calculations related to drilling fluid properties and components.
Core analysis provides direct measurements of reservoir rock properties that determine hydrocarbon production. Properly engineered core analysis is essential for formation evaluation, reservoir modeling, and production engineering. While fundamental measurements are unchanged, advances allow testing cores under reservoir conditions and acquiring simultaneous measurements of multiple properties. Cores are obtained using conventional, wireline-retrievable, or diamond-set coring bits and core barrels to cut and retain reservoir samples for analysis.
This document discusses principles of well logging. It describes how well logging aims to evaluate subsurface hydrocarbon accumulations through measuring properties in boreholes. It outlines different types of hydrocarbon traps and elements in a petroleum system. It then explains what a well log is and different types of logs used, including gamma ray, resistivity, sonic, and neutron logs. Gamma ray logs specifically measure natural radioactivity to distinguish between lithologies like sandstone and shale. The document provides details on interpreting gamma ray logs and calculating shale volume from gamma ray readings.
The document discusses well logging techniques. It begins by defining a well log as a continuous record of measurements made in a borehole that respond to variations in physical rock properties. It then discusses the concept of borehole invasion, where drilling mud contaminates the formation near the borehole. Key logging tools are described, including gamma ray, spontaneous potential, resistivity, density, neutron, and sonic logs. Porosity calculations using various logs are also presented. In particular, it focuses on how well logs can be used to determine lithology, porosity, fluid content and hydrocarbon saturation in geological formations.
This document discusses various cased hole logging tools and their applications. It provides information on tools for evaluating fluid type, casing and cement inspection, formation evaluation, and detecting problems like crossflow behind the pipe. Key tools mentioned include temperature logs for detecting fluid entry points, ultrasonic and electromagnetic tools for casing inspection, resistivity and neutron logs for water saturation, and tracer logs for measuring flow rates and identifying flow paths. The document provides detailed descriptions of how different tools can be used to obtain specific information needed to evaluate conditions in cased wellbores.
This document provides an overview of measurement while drilling (MWD), logging while drilling (LWD), rotary steerable systems (RSS), AutoTrak, and VertiTrak systems. It describes the components, operating principles, and objectives of MWD, LWD, and RSS. Key components of MWD include sensors, transmitters, telemetry systems, and surface systems. Mud pulse telemetry is highlighted as the commercially successful method to transmit downhole data to the surface. RSS systems allow continuous rotation while steering and are more complex than conventional systems but enable better penetration rates. The AutoTrak system uses a hybrid push-the-bit and point-the-bit approach in a closed-loop system to optimize well
The document provides an overview of spontaneous potential (SP) logging. It discusses that SP logging measures natural electrical potentials between the borehole and surface. Positive deflections indicate fresher formation water than mud filtrate, while negative deflections mean saltier formation water. SP can be used to determine formation water resistivity and estimate shale volume. Key applications include detecting permeable zones, correlating formations, and determining facies.
Drill stem test (DST) is one of the most famous on-site well testing that is used to unveil critical reservoir and fluid properties such as reservoir pressure, average permeability, skin factor and well potential productivity index. It is relatively cheap on-site test that is done prior to well completion. Upon the DST results, usually, the decision of the well completion is taken.
production engineering 2 topic.
which includes the production logging tools, its application, categories of application and also some uses of the log with example in the practical life and physics.
Well Log Interpretation and Petrophysical Analisis in [Autosaved]Ridho Nanda Pratama
PT. Halliburton Logging Service is a branch of Halliburton that provides completion and production services, drilling, and reservoir evaluation to oil companies in Sumatra, Indonesia. Dery Marsan and Ridho Nanda Pratama completed an on-job training program at Halliburton from August to September 2015. Their project involved well log analysis to determine water saturation and the most suitable water resistivity parameters in two formations, with the objectives of identifying water zones, evaluating challenges around determining petrophysical parameters, and analyzing well data. Their analysis identified both water-bearing and possible oil-bearing zones through evaluation of gamma ray, resistivity, neutron-density crossplots, and other well logs.
Drilling fluids are absolutely essential during the drilling process and considered the primary well control.
Know more now about such a very important component of the drilling process.
THE GOAL of research topic to explore the MUD LOGGING as bellow:
Primary objective is delineating hydrocarbon (shows & gas), necessary service also that to introduce high qualitatively and quantitatively obtains data from drilling as reference guide, and makes observations of drilled rocks, drilling fluids and drilling parameters in order to formulate and display concepts of the optional, the mud logging unit is the information data base on the rig site to serve both exploration and drilling program.
formation evaluation for reservoir engineeringmohammedsaaed1
Formation evaluation involves using tools to measure properties of rock and fluid in a wellbore to analyze hydrocarbon reservoirs. Key techniques include mud logging to monitor drilling, coring to obtain samples, open-hole wireline logging to characterize formations, logging while drilling for real-time data, formation testing to obtain pressure and fluid samples, and cased-hole logging for monitoring producing wells. The data is used to evaluate potential fluid flow and recovery from reservoirs.
Fundamentals of Petroleum Engineering Module 5Aijaz Ali Mooro
This document provides an overview of formation evaluation techniques including: mud logging to analyze drill cuttings; coring to obtain formation samples; open-hole logging using tools to measure electrical, acoustic, and radioactive properties; logging while drilling to obtain logs in real-time; formation testing to obtain pressure and fluid samples; and cased-hole logging for production monitoring and reservoir analysis. The goal of formation evaluation is to interpret measurements taken inside the wellbore to characterize reservoirs and quantify hydrocarbon reserves in the surrounding rock.
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. 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
The document provides information about resistivity logs including:
1. It discusses factors that affect resistivity like salinity, porosity, lithology, and clay content. It also explains the principles and theoretical considerations of resistivity logs.
2. It describes different resistivity tools like focused devices (Laterolog, Dual Laterolog, Spherically Focused Log) and unfocused devices (Normal Log, Lateral Log). It also discusses micro-resistivity devices.
3. The document discusses log characteristics including depth of investigation, bed resolution, and different scales used in resistivity logs. It explains how resistivity logs can be used for lithology identification, correlation, and permeability determination.
Mud logging involves collecting and analyzing drill cuttings and mud properties to interpret lithology and detect hydrocarbon shows. It relies on mud circulation from the mud pump through the drill string and annulus to the shale shaker where cuttings are examined. The mud logger monitors and records drilling parameters and cuttings data to help assess the producibility of formations. However, mud logging becomes less accurate at depths over 3000m where cuttings are mixed and it takes longer for mud to return to the surface.
- 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.
Directional drilling is the process of directing a wellbore along a non-vertical trajectory towards a predetermined target. It involves techniques like whipstocks, jet bits, and downhole motors to gradually build angle in the wellbore. There are three main types of directional well paths: Type I involves continuously building angle to a maximum and then holding; Type II involves building, holding, and dropping the angle; Type III only involves continuously building angle. Survey calculation methods like the average angle method are used to determine the wellbore position between survey points by calculating average inclination and azimuth angles.
This document provides an overview of drilling fluids and their role in drilling operations. It discusses the components and properties of drilling fluids, including continuous and dispersed phases as well as additives. The types of drilling fluids are described, including water-based muds, oil-based muds, gases, and gas-liquid mixtures. The key functions of drilling fluids to support drilling operations are also outlined. The document concludes with discussions of pressure terminologies and examples of calculations related to drilling fluid properties and components.
Core analysis provides direct measurements of reservoir rock properties that determine hydrocarbon production. Properly engineered core analysis is essential for formation evaluation, reservoir modeling, and production engineering. While fundamental measurements are unchanged, advances allow testing cores under reservoir conditions and acquiring simultaneous measurements of multiple properties. Cores are obtained using conventional, wireline-retrievable, or diamond-set coring bits and core barrels to cut and retain reservoir samples for analysis.
This document discusses principles of well logging. It describes how well logging aims to evaluate subsurface hydrocarbon accumulations through measuring properties in boreholes. It outlines different types of hydrocarbon traps and elements in a petroleum system. It then explains what a well log is and different types of logs used, including gamma ray, resistivity, sonic, and neutron logs. Gamma ray logs specifically measure natural radioactivity to distinguish between lithologies like sandstone and shale. The document provides details on interpreting gamma ray logs and calculating shale volume from gamma ray readings.
The document discusses well logging techniques. It begins by defining a well log as a continuous record of measurements made in a borehole that respond to variations in physical rock properties. It then discusses the concept of borehole invasion, where drilling mud contaminates the formation near the borehole. Key logging tools are described, including gamma ray, spontaneous potential, resistivity, density, neutron, and sonic logs. Porosity calculations using various logs are also presented. In particular, it focuses on how well logs can be used to determine lithology, porosity, fluid content and hydrocarbon saturation in geological formations.
This document discusses various cased hole logging tools and their applications. It provides information on tools for evaluating fluid type, casing and cement inspection, formation evaluation, and detecting problems like crossflow behind the pipe. Key tools mentioned include temperature logs for detecting fluid entry points, ultrasonic and electromagnetic tools for casing inspection, resistivity and neutron logs for water saturation, and tracer logs for measuring flow rates and identifying flow paths. The document provides detailed descriptions of how different tools can be used to obtain specific information needed to evaluate conditions in cased wellbores.
This document provides an overview of measurement while drilling (MWD), logging while drilling (LWD), rotary steerable systems (RSS), AutoTrak, and VertiTrak systems. It describes the components, operating principles, and objectives of MWD, LWD, and RSS. Key components of MWD include sensors, transmitters, telemetry systems, and surface systems. Mud pulse telemetry is highlighted as the commercially successful method to transmit downhole data to the surface. RSS systems allow continuous rotation while steering and are more complex than conventional systems but enable better penetration rates. The AutoTrak system uses a hybrid push-the-bit and point-the-bit approach in a closed-loop system to optimize well
The document provides an overview of spontaneous potential (SP) logging. It discusses that SP logging measures natural electrical potentials between the borehole and surface. Positive deflections indicate fresher formation water than mud filtrate, while negative deflections mean saltier formation water. SP can be used to determine formation water resistivity and estimate shale volume. Key applications include detecting permeable zones, correlating formations, and determining facies.
Drill stem test (DST) is one of the most famous on-site well testing that is used to unveil critical reservoir and fluid properties such as reservoir pressure, average permeability, skin factor and well potential productivity index. It is relatively cheap on-site test that is done prior to well completion. Upon the DST results, usually, the decision of the well completion is taken.
production engineering 2 topic.
which includes the production logging tools, its application, categories of application and also some uses of the log with example in the practical life and physics.
Well Log Interpretation and Petrophysical Analisis in [Autosaved]Ridho Nanda Pratama
PT. Halliburton Logging Service is a branch of Halliburton that provides completion and production services, drilling, and reservoir evaluation to oil companies in Sumatra, Indonesia. Dery Marsan and Ridho Nanda Pratama completed an on-job training program at Halliburton from August to September 2015. Their project involved well log analysis to determine water saturation and the most suitable water resistivity parameters in two formations, with the objectives of identifying water zones, evaluating challenges around determining petrophysical parameters, and analyzing well data. Their analysis identified both water-bearing and possible oil-bearing zones through evaluation of gamma ray, resistivity, neutron-density crossplots, and other well logs.
Drilling fluids are absolutely essential during the drilling process and considered the primary well control.
Know more now about such a very important component of the drilling process.
THE GOAL of research topic to explore the MUD LOGGING as bellow:
Primary objective is delineating hydrocarbon (shows & gas), necessary service also that to introduce high qualitatively and quantitatively obtains data from drilling as reference guide, and makes observations of drilled rocks, drilling fluids and drilling parameters in order to formulate and display concepts of the optional, the mud logging unit is the information data base on the rig site to serve both exploration and drilling program.
formation evaluation for reservoir engineeringmohammedsaaed1
Formation evaluation involves using tools to measure properties of rock and fluid in a wellbore to analyze hydrocarbon reservoirs. Key techniques include mud logging to monitor drilling, coring to obtain samples, open-hole wireline logging to characterize formations, logging while drilling for real-time data, formation testing to obtain pressure and fluid samples, and cased-hole logging for monitoring producing wells. The data is used to evaluate potential fluid flow and recovery from reservoirs.
Fundamentals of Petroleum Engineering Module 5Aijaz Ali Mooro
This document provides an overview of formation evaluation techniques including: mud logging to analyze drill cuttings; coring to obtain formation samples; open-hole logging using tools to measure electrical, acoustic, and radioactive properties; logging while drilling to obtain logs in real-time; formation testing to obtain pressure and fluid samples; and cased-hole logging for production monitoring and reservoir analysis. The goal of formation evaluation is to interpret measurements taken inside the wellbore to characterize reservoirs and quantify hydrocarbon reserves in the surrounding rock.
This document provides an overview of formation evaluation techniques used in petroleum exploration and development. It discusses various logging methods like mud logging, coring, open-hole logging using electrical, nuclear and acoustic tools, logging while drilling, formation testing including wireline formation testing and drill stem testing, and cased-hole logging techniques. The goal of formation evaluation is to detect and quantify oil and gas reserves using measurements taken inside the wellbore and interpret physical properties of rocks and contained fluids.
The document discusses the role of a Formation Evaluation Specialist. A Formation Evaluation Specialist must have general knowledge in several areas including: fundamental measurement theory for logging devices, log quality control, basic log interpretation principles, fundamentals of geophysics and petroleum geology, and fundamental principles of petroleum engineering. They are responsible for analyzing well log data, analyzing physical rock properties and how they relate to measurable properties from logs, and having a general knowledge across various formation evaluation disciplines. The document also provides background on well logs, the history of well logging, different types of well logging tools and methods, and important information to include in log headers.
This document discusses various geophysical well logging methods used to delineate aquifers and estimate water quality, including resistivity, spontaneous potential, radioactivity, neutron, temperature, and fluid resistivity logging. Resistivity logging measures the resistivity of formations and can help determine lithology, porosity, and fluid salinity. Spontaneous potential logging indicates bed boundaries and distinguishes shale from permeable rocks. Radioactivity logging uses natural gamma rays or gamma-gamma techniques to identify lithology and determine porosity. Neutron logging measures hydrogen content to estimate porosity and moisture levels. Temperature and fluid resistivity logging provide additional information about groundwater. These geophysical logs provide critical subsurface data for groundwater exploration and management.
WELL LOG : Types of Logs, The Bore Hole Image, Interpreting Geophysical Well Logs, applications, Production logs, Well Log Classification and Cataloging
This document discusses well logging techniques used to determine rock properties. It describes how porosity, permeability, and fluid content can be measured through different logging methods, including gamma ray, resistivity, density, and sonic logs. Well logs provide critical information on lithology, stratigraphy, porosity, fluid saturation, and other properties important for reservoir modeling and structural analysis. The document provides details on various logging tools and techniques and how they are used to evaluate properties like shale content, fluid type, and hydrocarbon presence.
This document provides an overview of key concepts in petroleum engineering, including permeability, geophysics techniques for oil and gas exploration like seismic surveys, and reservoir engineering essentials. It discusses permeability measurement methods, factors that affect permeability, and types of permeability. It also summarizes different geophysics techniques like seismic surveys, gravity surveys, electromagnetic surveys, and magnetic surveys. Finally, it outlines the essential elements and processes for hydrocarbon accumulation, including the need for a trap, reservoir, source rock, and seal.
The document discusses the classification of well logs. It explains that logs can be classified based on their technology (open hole vs cased hole logs) or their function (lithology, electrical, porosity, nuclear logs). Open hole logs are run before casing while cased hole logs are done after casing through the metal piping. Various logging tools are described, including gamma ray, resistivity, density, neutron, and sonic logs which provide data on formation properties like lithology, porosity, and fluid content. Nuclear logs using gamma rays and neutrons can evaluate formations through casing as well.
Data acquisition and Log Evaluation in a High-Density Cesium Formate Fluid John Downs
1) The document discusses evaluating well logs in high density cesium formate drilling mud. Cesium formate mud poses challenges for log evaluation due to its high density, electrical conductivity, and nuclear properties.
2) A novel method is presented to correct density logs measured in cesium formate mud. It uses the linear relationship between measured density and photoelectric effect to calculate the invaded zone saturation and true formation density.
3) The method involves using photoelectric measurements to correct the measured density log and calculate saturation of the invaded zone, then applying density-porosity relationships to obtain the final porosity measurement.
Introduction
Petrophysic of the rocks
It is the study of the physical and chemical properties of the rocks related to the pores and fluid distribution
Porosity, is ratio between volume of void to the total voids of the rock.
Permeability, is ability of a porous material to allow fluids to pass through it.
Electric, most of the sedimentary rocks don’t have conductivity.
Radiation, clay rocks have 40K, radiate alpha ray.
Hardness, it depends on the cementing material and thickness of the sediments.
WELL LOGGING
The systematic recording of rock properties and it’s fluid contents in wells being drilled or produced to obtain various petrophysical parameters and characteristics of down hole sequences (G.E Archie 1950).
The measurement versus depth or time, or both, of one or more physical properties in a well.
These methods are particularly good when surface outcrops are not available, but a direct sample of the rock is needed to be sure of the lithology.
A wide range of physical parameters can be measured.
In some cases, the measurements are not direct, it require interpretation by analogy or by correlating values between two or more logs run in the same hole.
Provide information on lithology, boundaries of formations and stratigraphic correlation.
Determine Porosity, Permeability, water, oil and gas saturation.
Reservoir modeling and Structural studies… etc.
Types of Well Logging
Logs can be classified into several types under different category
Permeability and lithology Logs
Gamma Ray log
Self Potential [SP] log
Caliber log
Porosity Logs
Density log
Sonic log
Neutron log
Electrical Logs
Resistivity Log
For contact : omerupto3@gmail.com
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.
Deterministic Petrophysic by Senergy.pptRickySitinjak
The document discusses the workflow for evaluating well logs to determine lithology and clay volume. It describes how gamma ray, resistivity, neutron-density crossplots and other logs can be used to identify lithology and estimate clay volume. It emphasizes comparing log interpretations to core data and selecting appropriate parameters that may vary with zone or formation properties. Integrating different data types is important for a robust evaluation.
This document describes an experiment to prepare core plugs from rock core samples. The objectives are to determine physical properties of the rock like porosity and permeability. The procedure involves slabbing the core, drilling plugs from the core using a core plugging machine, and analyzing the plugs through routine and special core analysis. Routine analysis provides properties for reservoir evaluation while special analysis gives information on multiphase flow and wettability. The results of core analysis are used to improve hydrocarbon recovery and production predictions.
Well logs are obtained by lowering measuring tools into wells to record properties of rock formations. They provide a signature of physical characteristics like porosity, lithology, and fluid saturation. Common logs measure resistivity, spontaneous potential, gamma radiation, neutrons, sonic velocity, and nuclear magnetic resonance to interpret rock and fluid properties. Logs can be open or cased hole and employ natural or induced phenomena to characterize formations.
Well logging involves lowering instruments into boreholes to record properties of rock formations. It provides critical information for oil and gas, groundwater, and mineral exploration. Key logs measure natural gamma radiation, electrical resistivity, acoustic properties, and nuclear properties like neutron count. Together these logs characterize porosity, lithology, fluid content and other formation features. Well logging has evolved significantly since the first electric log in 1927, with new tools, digital acquisition, and measurement-while-drilling capabilities. It remains a core technology for understanding subsurface geology.
Well lod ,well Testing and mud logging Ghulam Abbas AbbasiUniversity of Sindh
Well logging records measurements made in boreholes to characterize underground formations. Key logs described include gamma ray, which measures natural radioactivity to identify shale; spontaneous potential, which indicates lithology; caliper, which measures borehole size; resistivity, which distinguishes water and hydrocarbon zones; and neutron, which determines porosity. Mud logging continuously monitors drilling mud and cuttings for gas readings. Well testing evaluates reservoir properties through daily tests and drill stem tests to determine flow rates and commercial potential.
Coures-Formation Evalution for petroleum Engineering -heriot watt university.pdfAdnanAhmadJadoon
The document provides information on formation evaluation for petroleum engineering. It discusses the history of well logging, beginning with the first well log created in 1927 in France. It describes various well logging tools and techniques, including wireline logging, logging while drilling (LWD), and measurement while drilling (MWD). The document also covers log data acquisition and transmission methods. Additionally, it discusses key concepts in formation evaluation like reservoir and geological modeling, porosity, permeability, saturation, and fluid properties. The objectives of formation evaluation are outlined as understanding rock properties, principles of wireline logging tools, log interpretation, and quantifying parameters like porosity, lithology, fluid saturation and permeability.
The document describes an experiment to plug core samples taken from a reservoir rock. Core plugging involves cutting cylindrical plugs from core samples using a specialized plugging machine. This is done to prepare the samples for further reservoir tests and measurements in the lab. Standard plugs are used to determine properties like porosity, permeability and fluid saturation. The procedure involves securing the core sample in the plugging machine, drilling cylindrical plugs using lubricants, and trimming the plugs to the required dimensions for testing. Core plugging is an important step in analyzing core samples to evaluate reservoirs.
Prospecting by radioactivity logging methodsPramoda Raj
This document discusses various well logging methods used in geophysical exploration, specifically focusing on radioactivity logging. It describes four main types of radioactivity logs: gamma ray logs, neutron-gamma ray logs, pulsed neutron logs, and formation density logs. Gamma ray logs measure natural radioactivity to characterize rock formations. Neutron-gamma ray logs measure induced radioactivity to evaluate porosity. Pulsed neutron logs can distinguish between oil, water, and gas, and are not influenced by borehole conditions. Formation density logs measure gamma ray energy loss to determine formation density and porosity. The document provides details on the principles and applications of each method.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Introducing Milvus Lite: Easy-to-Install, Easy-to-Use vector database for you...Zilliz
Join us to introduce Milvus Lite, a vector database that can run on notebooks and laptops, share the same API with Milvus, and integrate with every popular GenAI framework. This webinar is perfect for developers seeking easy-to-use, well-integrated vector databases for their GenAI apps.
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
20 Comprehensive Checklist of Designing and Developing a WebsitePixlogix Infotech
Dive into the world of Website Designing and Developing with Pixlogix! Looking to create a stunning online presence? Look no further! Our comprehensive checklist covers everything you need to know to craft a website that stands out. From user-friendly design to seamless functionality, we've got you covered. Don't miss out on this invaluable resource! Check out our checklist now at Pixlogix and start your journey towards a captivating online presence today.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Goodbye Windows 11: Make Way for Nitrux Linux 3.5.0!SOFTTECHHUB
As the digital landscape continually evolves, operating systems play a critical role in shaping user experiences and productivity. The launch of Nitrux Linux 3.5.0 marks a significant milestone, offering a robust alternative to traditional systems such as Windows 11. This article delves into the essence of Nitrux Linux 3.5.0, exploring its unique features, advantages, and how it stands as a compelling choice for both casual users and tech enthusiasts.
3. Formation Evaluation
▪ What is Formation Evaluation?
▪ Formation Evaluation (FE) is the process of
interpreting a combination of measurements taken
inside a wellbore to detect and quantify oil and
gas reserves in the rock adjacent to the well. FE
data can be gathered with wireline logging
instruments or logging-while-drilling tools .
▪ Study of the physical properties of rocks and the
fluids contained within them.
▪ Data are organized and interpreted by depth and
represented on a graph called a log (a record of
information about the formations through which a
well has been drilled).
4. Formation Evaluation
▪ Why Formation Evaluation?
▪ To evaluate hydrocarbons reservoirs and predict
oil recovery.
▪ To provide the reservoir engineers with the
formation’s geological and physical parameters
necessary for the construction of a fluid-flow
model of the reservoir.
▪ Measurement of in situ formation fluid pressure
and acquisition of formation fluid samples.
▪ In petroleum exploration and development,
formation evaluation is used to determine the
ability of a borehole to produce petroleum.
5. Mud Logging
▪ Mud logging (or Wellsite Geology) is a well logging
process in which drilling mud and drill bit cuttings
from the formation are evaluated during drilling and
their properties recorded on a strip chart as a visual
analytical tool and stratigraphic cross sectional
representation of the well.
▪ Provide continuous record of penetration rate,
lithology and hydrocarbon shows.
▪ These information supports wireline log data.
▪ From the cuttings, an oil stains or odor of oil may be
detected, become an excellent qualitative indicator.
▪ The fluorescent lamp is also a great help in detecting
oil shows.
6. Mud Logging
▪ The gas record and lithological sample are plotted
along with surface parameters such as rate of
penetration (ROP), Weight On Bit (WOB),rotation
per minute etc. on the mudlog which serve as a tool
for the drilling engineers and mud engineers.
▪ Some problem: a discrepancy between the time the
rock was drilled and the time it reached the surface
– particularly for deep wells, where it take two or
move hours to reach the surface.
7. Coring
▪ One way to get more detailed
samples of a formation is by coring,
where formation sample is drilled
out by means of special bit.
▪ This sample can provide:
▪ Detailed lithological decscription.
▪ Porosity, permeability, fluid
saturation and grain density.
▪ These parameters are measured in
the laboratory and serve as a basis
for calibrating the response of the
porosity logging tools and to
establish a porosity/permeability
relationship.
8. Coring
▪ Two techniques commonly used at
present. The first is the "whole
core", a cylinder of rock, usually
about 3" to 4" in diameter and up to
50 feet (15 m) to 60 feet (18 m) long.
▪ It is cut with a "core barrel", a
hollow pipe tipped with a ring-shaped
diamond chip-studded bit that can
cut a plug and bring it to the surface.
▪ Taking a full core is an expensive
operation that usually stops or slows
drilling operation, and can be done
only before the drilling has been
done.
Coring Tool & Core Barrel
9. Coring
▪ The other, cheaper, technique for obtaining samples
of the formation is "Sidewall Coring". In this method,
a steel cylinder—a coring gun—has hollow-point steel
bullets mounted along its sides and moored to the
gun by short steel cables.
▪ The coring gun is lowered to the bottom of the
interval of interest and the bullets are fired
individually and the core will be retrieved.
▪ Advantages of this technique are low cost and the
ability to sample the formation after it has been
drilled.
10. Core Preservation
▪ Once the core is retrieve to surface then it is
important that it should remain as unchanged as
possible.
▪ The core should be prevented from drying out,
coming into contact with oxygen or being
mechanically damaged.
▪ Core barrel is filled with resin to prevent the
core from moving and to minimize the exposed
surface area.
▪ Freezing the core in freezer containers.
▪ Core sample is wrapped in a plastic film, aluminium
foil and then dipped in molten wax.
11. Core Analysis
▪ Can be divided into two categories:
▪ Conventional Core Analysis.
▪ Special Core Analysis.
▪ Conventional Core Analysis.
▪ The core is usually slabbed, cut lengthwise to
make the structure visible.
▪ Provides information on lithology, residual fluid
saturation, ambient porosity, ambient gas
permeability and grain density.
14. Core Analysis
▪ Special Core Analysis :
Provides the following information:
▪ Porosity and permeability at elevated confining
stress.
▪ Electrical properties such as formation factor
and resistivity index.
▪ Capillary pressure.
▪ Wettability and relative permeability.
▪ Mechanical rock properties such as
compressibility.
▪ Waterflood sensitivity for injectivity and well
performance.
15. Open-hole Logging
▪ Open-hole logging, also known as
well logging is the practice of
making a detailed record (a well
log) of the geologic formations
penetrated by a borehole.
▪ Open hole logs are run before
the oil or gas well is lined with
pipe or cased
16. Principal of Well Logging
▪ A well log is a record of certain formation data
versus depth.
▪ The appropriate downhole logging tools instrument
called ‘sonde’, about 3.5 inches in diameter is
lowered into mud-filled hole on logging cable.
▪ This tools will measure the electrical, acoustic, and
radioactive properties of the formation.
▪ The result will be analyzed to determine which of
the layers are porous and permeable, and likely to
contain hidrocarbon.
▪ A depth calibration wheel records the length of
cable in the hole.
17. Principal of Well Logging
▪ Survey is normally done
from the bottom up. As
the sonde is pulled up the
hole, a continuous
measurement signal is sent
to the surface where the
data is processed and
recorded as a curve.
5185
5195
5205
5215
5225
5235
5245
5255
5265
5275
5285
5295
5305
5315
5325
5335
5345
5355
5365
5375
5385
5395
5405
5415
-50 0 50 100 150
GR
18.
19. Electrical Logs
▪ Developed by Conrad & Marcel Schlumberger (who
founded Schlumberger Limited), and intoduced to
the US in 1929.
▪ Can be divided into two main types: measurement
of natural electrical current in the rock (SP Log),
and measurement of induced electrical current
(Resistivity Log and Induction Log).
20. (1) Spontaneous Potential (SP) Log
▪ Also known as Self Potential
Log.
▪ SP Log record weak electrical
currents that flow naturally in
the rock next to the wellbore
(natural electricity).
▪ The log shows the boundaries
and thickness of each layer of
rock, especially permeable
(sandstone) and impermeable
(shale).
▪ Because the SP Log is so
simple to obtain and provide
such basic information, it is
the most common log.
5185
5195
5205
5215
5225
5235
5245
5255
5265
5275
5285
5295
5305
5315
5325
5335
5345
5355
5365
5375
5385
5395
5405
5415
-100 -50 0 50 100
SP
Sandstone
Sandstone
Shale
Shale
Shale
21. (1) Spontaneous Potential (SP) Log
▪ Useful for:
▪ Detecting permeable beds
and it thickness.
▪ Locating their boundaries
and permitting correlation
of such beds.
▪ Determining formation
water resistivity.
▪ Qualitative indication of
bed shaliness.
5185
5195
5205
5215
5225
5235
5245
5255
5265
5275
5285
5295
5305
5315
5325
5335
5345
5355
5365
5375
5385
5395
5405
5415
-100 -50 0 50 100
SP
Sandstone
Sandstone
Shale
Shale
Shale
22. (2) Resistivity Logs
▪ Use to measure the resistivity of the formation,
and thus the possibility of hc shows.
▪ A sonde sends an electrical signal through the
formation and relays it back to a receiver at the
surface (induced electricity). The surface detector
will measure the formation’s resistance to the
current.
▪ A rock which contains an oil and/or gas saturation
will have a higher resistivity than the same rock
completely saturated with formation water.
23. (3) Induction Logs
▪ Use to measure the conductivity of the formation,
and thus the possibility of hc shows.
▪ A rock which contains an oil and/or gas saturation
will have a lower conductivity than the same rock
completely saturated with formation water.
▪ Induction logs use an electric coil in the sonde to
generate an alternating current loop in the
formation by induction.
▪ Induction tools t give best results when mud
resistivity is high with respect to formation
resistivity, i.e., fresh mud or non-conductive fluid.
In oil-base mud, which is non conductive, induction
logging is the only option available.
24. (4) Dielectric Logs
▪ Responds essentially to water and is unaffected by
the presence of hydrocarbons.
▪ Particularly important in determining the
irreducible water saturation when oil-based muds
are used.
25. Nuclear Logs
▪ Just as SP and resistivity logs record natural and
induced electrical currents, nuclear logs (also
called radioactivity logs) record natural and
induced radioactivity.
▪ Three type of logs: Gamma Ray Log, Neutron Log
and Formation Density Log.
26. (1) Gamma Ray Log
▪ Record the natural γ-
radioactivity of rocks
surrounding the borehole.
▪ The γ-radiation arises from
three elements present in the
rocks, isotopes of potassium,
uranium and thorium.
▪ Useful for defining shale beds
because K, U and Th are largely
concentrated in association
with clay minerals.
▪ It is used to define permeable
beds when SP log cannot be
employed (eg. When Rmf = Rw).
5185
5195
5205
5215
5225
5235
5245
5255
5265
5275
5285
5295
5305
5315
5325
5335
5345
5355
5365
5375
5385
5395
5405
5415
-50 0 50 100 150
GR
Sandstone
Sandstone
Shale
Shale
Shale
27. (2) Neutron Log
▪ To obtain a neutron log, a sonde sends atomic
particles called neutrons through the formation.
▪ When the neutrons collide with hydrogen, the
hydrogen slows them down.
▪ The response of the devise is primarily a function
of the hydrogen nuclei concentration.
▪ When the detector records slow neutrons, it means
a lot of hydrogen is present – main component of
water and hydrocarbon, but not of rocks.
▪ Considered as porosity log because hydrogen is
mostly present in pore fluids (water, hydrocarbons)
the count rate can be converted into apparent
porosity.
28. (3) Formation Density Log
▪ This devise measure number of photon then be
related to electron density of the formation.
▪ Electron density is related to an apparent bulk
density which equivalent to formation bulk density.
▪ Useable to detect formation lithology.
29. Sonic or Acoustic Logs
▪ Provide continuous record of the time taken in
microsecond/foot by sound wave to travel from the
transmitter to the receiver n the sonde.
▪ Velocity of sound through a given formation is a
function of its lithological and porosity.
▪ Dense, low porosity rocks are characterized by
high velocity of sound wave and vise-versa for
porous and less dense formation.
30. Logging While Drilling
▪ One of the major drawbacks of wireline
information is that it is received several hours to
several weeks after the borehole is drilled.
▪ During this time period, the formation can undergo
significant alteration, especially in its fluid
saturation, effective porosity, and relative perm.
▪ LWD allow wireline-type information to be
available as near as real-time as possible.
▪ Logging While Drilling (LWD) is a technique of
conveying well logging tools into the well borehole
downhole as part of the bottom hole assembly
(BHA).
31. Logging While Drilling
▪ Some available measurement in LWD technology:
▪ Gamma Ray
▪ Resistivity
▪ Density
▪ Neutron
▪ Sonic (fairly recent)
▪ Formation pressure
▪ Formation fluid sampler
▪ Borehole caliper (Ultra sonic azimuthal caliper,
and density caliper).
32. Formation Testing
◼ Is a means of obtaining information concerning the
liquid and pressure in an open-hole formations.
◼ Three methods:
■ Wireline testing
■ Drill stem test (DST)
■ Well Test Analysis
33. Wireline Testing
◼ Provide reservoir fluid samples, reservoir pressure,
an indication of fluid mobility and information on
reservoir continuity.
◼ Two types: Repeat Formation Tester (RFT) and
Formation Interval Tester (FIT).
◼ The RFT is run into the hole and a continuous
digital readout of hydrostatic pressure is obtained.
◼ At any point in the hole the tool may be actuated
to force a rubber pad against the wall of the hole,
and a tube in the centre of the pad is forced hard
against the formation.
◼ The formation fluid will flow to the chamber
through the tube.
34. Wireline Testing
◼ The FIT is used for single test – only one pressure
reading and one fluid sample for each run.
◼ A tool is actuated (a pad is tightly against the
formation to form a seal against hydrostatic
pressure of the fluid in the hole).
◼ A shaped charge is then fired into the fm, opening
a passageway for fm fluids to flow into a chamber
in the tool. At he same time the fm pressure will be
recorded.
35. Drillstem Test (DST)
◼ A drill stem test (DST) is a procedure for isolating
and testing the surrounding geological formation
through the drill stem.
◼ The test is a measurement of pressure behavior at
the drill stem and is a valuable way to obtain
important sampling information on the formation
fluid and to establish the probability of commercial
production.
◼ The test is made by lowering a valve, a packer, and
a length of perforated tailpipe to the level of
formation.
◼ The packer set against the wall of the borehole so
that it seals off the test interval from the mud
column above.
36. Drillstem Test (DST)
◼ The valve is then opened, and
the fm fluid will flow to the
surface through the drillpipe.
◼ The amount of fluid produced
will represent the fluid
production can be expected
from the well.
37. Well Test Analysis
◼ Two types of testing: pressure build-up and draw
down test.
◼ The primary objectives of well testing are to
establish:
◼ Permeability thickness (Kh) and permeability (K)
◼ Stratification (by sequential testing of layer).
◼ Well productivity.
◼ Investigate reservoir boundaries and size.
◼ The amount of fluid produced will represent the
fluid production can be expected from the well.
38. Cased-hole Logging
◼ Two major areas of cased-hole logging:
◼ Production logging.
◼ Reservoir monitoring.
◼ Production logging refers to obtaining production
or injection profiles over a completed interval.
◼ Reservoir monitoring refers to obtaining real time
information about changes in hydrocarbon
saturation.
◼ Crucial for understanding water contact movement.
◼ Other services include cement bond log which used
to evaluate the degree of isolation provided by the
casing cement.