Formation damage can occur through physical, chemical, and bacterial mechanisms. The formation damage process involves filter cake formation and drilling mud formulation. Formation damage sources include drilling, completion, workover, stimulation, production, and injection operations. Common damage mechanisms are particle invasion, clay swelling/dispersion, scale precipitation, and fines migration. Remedial measures include acidizing, fracturing, clay stabilization, and surfactant treatments. Proper mud system design aims to minimize invasion and filtrate loss into the formation.
DAMAGE ISSUES IMPACTING THE PRODUCTIVITY OF TIGHT GAS PRODUCING FORMATIONS; Formation Damage; Fracturing/Refracturing; Hydraulically Fractured; Tight Gas Reservoir; Economic Tight Gas Reservoir Production
The efficiency of enhanced oil recovery method is a measure of the ability to provide greater hydrocarbon recovery than by natural depletion, at an economically attractive production rate.
Facebook Page: https://www.facebook.com/petroleumengineeringz
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DAMAGE ISSUES IMPACTING THE PRODUCTIVITY OF TIGHT GAS PRODUCING FORMATIONS; Formation Damage; Fracturing/Refracturing; Hydraulically Fractured; Tight Gas Reservoir; Economic Tight Gas Reservoir Production
The efficiency of enhanced oil recovery method is a measure of the ability to provide greater hydrocarbon recovery than by natural depletion, at an economically attractive production rate.
Facebook Page: https://www.facebook.com/petroleumengineeringz
Blogspot: http://petroleumengineeringsociety.blogspot.com/
I hope this presentation helps you to understand why we use acidizing process and calculations needed to perform the optimum acidizing .
Any questions contact me at karim.elfarash@std.suezuniv.edu.eg
Selection of the best artificial lift systems for the well depend on location, depth, estimated production, reservoir properties, and many other factors. Here is an overview on selection criteria for the best results
The problem of water and gas coning has plagued the petroleum industry for decades. Water or gas encroachment in oil zone and thus simultaneous production of oil & water or oil & gas is a major technical, environmental and economic problems associated with oil and gas production. This can limit the productive life of the oil and gas wells and can cause severe problems including corrosion of tubulars, fine migration, hydrostatic loading etc. The environmental impact of handling, treating and disposing of the produced water can seriously affect the economics of the production. Commonly, the reservoirs have an aquifer beneath the zone of hydrocarbon. While producing from oil zone, there develops a low pressure zone as a result of which the water zone starts coning upwards and gas zone cones down towards the production perforation in oil zone and thus reducing the oil production. Pressure enhanced capillary transition zone enlargement around the wellbore is responsible for the concurrent production. This also results in the loss of water drive and gas drive to a certain extent.
Numerous technologies have been developed to control unwanted water and gas coning. In order to design an effective strategy to control the coning of oil or gas, it is important to understand the mechanism of coning of oil and gas in reservoirs by developing a model of it. Non-Darcy flow effect (NDFE), vertical permeability, aquifer size, density of well perforation, and flow behind casing increase water coning/inflow to wells in homogeneous gas reservoirs with bottom water are important factors to consider. There are several methods to slow down coning of water and/or gas such as producing at a certain critical rate, polymer injection, Downhole Water Sink (DWS) technology etc.
Shubham Saxena
B.Tech. petroleum Engineering
IIT (ISM) Dhanbad
All petroleum companies aims to reach maximum production naturally by saving the pay zone characteristics to avoid using different enhanced oil recovery techniques.
Now it is possible by Special Core analysis techniques. Simple analysis on the surface; great time saving while drilling the subsurface.
Trying in this presentation to explain the main topics of (FDT).
For any further information, please contact me on : abdalrahmanibrahim209@gamil.com
Skin factor is a dimensionless parameter that quantifies the formation damage around the wellbore. it also can be negative (which indicates improvement in flow) OR positive (which means formation damage exists). Positive skin can lead to severe well production issues and thus reducing the well revenue
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 presentation tackles one of the problem in oil industry, which is sand that is produced in the oil wells. Brief description about the problem, its causes, effects and solutions are proposed.
Producing Non Toxic Drilling Fluids.pptxAbhay Rajput
The PowerPoint presentation on the production of non-toxic drilling fluids offers a detailed examination of drilling fluids, their essential role in drilling operations, and the significant shift towards non-damaging alternatives. The presentation opens with a clear definition of what drilling fluids are and elucidates their critical function in the drilling industry, including lubricating the drill bit, transporting drill cuttings to the surface, and maintaining hydrostatic pressure to prevent well blowouts.
It then categorizes the various types of drilling fluids, such as water-based, oil-based, and synthetic-based muds, each with unique properties and applications tailored to different drilling environments. The presentation systematically outlines the functions of drilling fluids, emphasizing their importance in cooling the drill bit, stabilizing the wellbore, and preventing corrosion.
A significant portion of the presentation is dedicated to discussing the problems associated with conventional drilling fluids. It highlights the environmental impact and health risks linked to the use of traditional muds, such as contamination of groundwater, harm to marine life, and the potential for hazardous exposure to workers.
The focus shifts to non-damaging drilling fluids, presenting innovative formulations that minimize environmental impact and health hazards. This section delves into the development and benefits of using non-toxic drilling fluids, showcasing their effectiveness in reducing the ecological footprint of drilling operations without compromising performance.
The presentation makes a compelling case for the transition to non-damaging drilling fluids over conventional ones, arguing that the advantages extend beyond environmental and health benefits. It discusses the operational efficiencies, cost-effectiveness in the long term, and regulatory compliance that non-toxic fluids offer, making them a prudent choice for sustainable drilling practices.
In summary, the PowerPoint presentation on the production of non-toxic drilling fluids comprehensively covers the necessity and functions of drilling fluids, the challenges posed by conventional muds, and the compelling advantages of adopting non-damaging alternatives. It underscores the importance of moving towards more sustainable drilling practices to mitigate environmental risks and health hazards, aligning with global sustainability goals.
I hope this presentation helps you to understand why we use acidizing process and calculations needed to perform the optimum acidizing .
Any questions contact me at karim.elfarash@std.suezuniv.edu.eg
Selection of the best artificial lift systems for the well depend on location, depth, estimated production, reservoir properties, and many other factors. Here is an overview on selection criteria for the best results
The problem of water and gas coning has plagued the petroleum industry for decades. Water or gas encroachment in oil zone and thus simultaneous production of oil & water or oil & gas is a major technical, environmental and economic problems associated with oil and gas production. This can limit the productive life of the oil and gas wells and can cause severe problems including corrosion of tubulars, fine migration, hydrostatic loading etc. The environmental impact of handling, treating and disposing of the produced water can seriously affect the economics of the production. Commonly, the reservoirs have an aquifer beneath the zone of hydrocarbon. While producing from oil zone, there develops a low pressure zone as a result of which the water zone starts coning upwards and gas zone cones down towards the production perforation in oil zone and thus reducing the oil production. Pressure enhanced capillary transition zone enlargement around the wellbore is responsible for the concurrent production. This also results in the loss of water drive and gas drive to a certain extent.
Numerous technologies have been developed to control unwanted water and gas coning. In order to design an effective strategy to control the coning of oil or gas, it is important to understand the mechanism of coning of oil and gas in reservoirs by developing a model of it. Non-Darcy flow effect (NDFE), vertical permeability, aquifer size, density of well perforation, and flow behind casing increase water coning/inflow to wells in homogeneous gas reservoirs with bottom water are important factors to consider. There are several methods to slow down coning of water and/or gas such as producing at a certain critical rate, polymer injection, Downhole Water Sink (DWS) technology etc.
Shubham Saxena
B.Tech. petroleum Engineering
IIT (ISM) Dhanbad
All petroleum companies aims to reach maximum production naturally by saving the pay zone characteristics to avoid using different enhanced oil recovery techniques.
Now it is possible by Special Core analysis techniques. Simple analysis on the surface; great time saving while drilling the subsurface.
Trying in this presentation to explain the main topics of (FDT).
For any further information, please contact me on : abdalrahmanibrahim209@gamil.com
Skin factor is a dimensionless parameter that quantifies the formation damage around the wellbore. it also can be negative (which indicates improvement in flow) OR positive (which means formation damage exists). Positive skin can lead to severe well production issues and thus reducing the well revenue
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 presentation tackles one of the problem in oil industry, which is sand that is produced in the oil wells. Brief description about the problem, its causes, effects and solutions are proposed.
Producing Non Toxic Drilling Fluids.pptxAbhay Rajput
The PowerPoint presentation on the production of non-toxic drilling fluids offers a detailed examination of drilling fluids, their essential role in drilling operations, and the significant shift towards non-damaging alternatives. The presentation opens with a clear definition of what drilling fluids are and elucidates their critical function in the drilling industry, including lubricating the drill bit, transporting drill cuttings to the surface, and maintaining hydrostatic pressure to prevent well blowouts.
It then categorizes the various types of drilling fluids, such as water-based, oil-based, and synthetic-based muds, each with unique properties and applications tailored to different drilling environments. The presentation systematically outlines the functions of drilling fluids, emphasizing their importance in cooling the drill bit, stabilizing the wellbore, and preventing corrosion.
A significant portion of the presentation is dedicated to discussing the problems associated with conventional drilling fluids. It highlights the environmental impact and health risks linked to the use of traditional muds, such as contamination of groundwater, harm to marine life, and the potential for hazardous exposure to workers.
The focus shifts to non-damaging drilling fluids, presenting innovative formulations that minimize environmental impact and health hazards. This section delves into the development and benefits of using non-toxic drilling fluids, showcasing their effectiveness in reducing the ecological footprint of drilling operations without compromising performance.
The presentation makes a compelling case for the transition to non-damaging drilling fluids over conventional ones, arguing that the advantages extend beyond environmental and health benefits. It discusses the operational efficiencies, cost-effectiveness in the long term, and regulatory compliance that non-toxic fluids offer, making them a prudent choice for sustainable drilling practices.
In summary, the PowerPoint presentation on the production of non-toxic drilling fluids comprehensively covers the necessity and functions of drilling fluids, the challenges posed by conventional muds, and the compelling advantages of adopting non-damaging alternatives. It underscores the importance of moving towards more sustainable drilling practices to mitigate environmental risks and health hazards, aligning with global sustainability goals.
A brief explanation of parameters affecting asphaltene and Wax (Paraffins) Deposition, The document also covers techniques available to alleviate the problem
DRILLING FLUIDS FOR THE HPHT ENVIRONMENTMohan Doshi
A BRIEF REVIEW OF THE DRILLING FLUIDS FOR DRILLING HPHT WELLS. HPHT WELLS ARE NOT BUSINESS AS USUAL AND THE SAME APPLIES TO HPHT DRILLING FLUIDS. THE FLUID CHEMISTRY AND THE FLUID COMPOSITION HAVE TO BE TAILORED TO MEET THE RIGORS OF THE HIGH TEMPERATURE ENVIRONMENT
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.
Scale Formation problems in Oil & Gas Industry : Its reduction procedures by ...Sachin Nambiar
This paper is a literature review on methods to control scale formation using various chemicals; and its economic feasibility in the petroleum industry.
Field development plan, rate of production,SYED NAWAZ
It gives you an idea about an impact of reservoir damage on production rate
Hello Everyone,
Follow my youtube channel "PETROLEUM UNIVERSE" https://lnkd.in/gjZgb7E
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in detail description of previous gate papers of petroleum engineering and some assumptions for 2021, with a brief of future steps. reference textbooks
Complete Casing Design with types of casing, casing properties, casing functions, design criteria and properties used for designing and one numerical problem
it gives you an indetail information about gas formation volume factor formula, derivation, constant information, and a numerical problem for better understanding
This question appears in GATE Petroleum Engineering in which they have ask to calculate the skin factor and this question belongs to oil and gas well testing subject
This question appears in GATE 2016 Petroleum Engineering in which they ask us to estimate the total time required for reservoir deliver the oil and gas to the surface and obviously it's recovery factor
this question appears in GATE 2016 Petroleum Engineering in which they have ask us to calculate the input power required for a pump to deliver the required operation
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
6. Origins of formation damage & Remedies
Formation damage during drilling:
Damage mechanism
1. Particle invasion/ Filter cake
2. Swelling and dispersion of indigenous
reservoir clays by the mud filtrate
3. Mutual precipitation of soluble salts
in the filtrate and formation water
4. Slumping of unconsolidated sands
5. Water block / Emulsion block
Remedial measures
1. Matrix acidization,
Perforation, H.fracturing
2. Matrix acidization
3. Matrix acidization
4. Sand consolidation
techniques, Frac and Pack
5. Surfactant treatment,
Matrix acidization
7. Origins of formation damage & Remedies
Formation damage during cementing:
Damage mechanism
1. Fines migration from the
cement slurry into the
formation
2. Precipitation of solids from
the cement within the
formation
3. Precipitation of expansive
secondary minerals following
reservoir mineral dissolution
Remedial measures
1. Matrix acidization,
Perforation, Hydraulic
fracturing
2. Matrix acidization,
Perforation
3. Acidization
8. Origins of formation damage & Remedies
During well completion & workover
Damage mechanism
1. Hydration and swelling of clay
minerals
2. Movement and plugging by clay
size particles in the formation
3. Plugging by invading materials
from the wellbore fluids
4. Emulsion and water blocks due to
lost wellbore fluid
5. Relative permeability effects
6. Precipitation of scales
7. Plugged perforations due to
improper perforating conditions
Remedial measures
1. Matrix acidization ,Clay
stabilization
2. Matrix acidization ,Clay
stabilization
3. Matrix acidization
4. Surfactant treatment,
Matrix acidization
5. Surfactant treatment
6. Acidization
7. Acidization, Perforation
9. Origins of formation damage & Remedies
During sand control
Damage mechanism
• Fines migration
• Perforation plugging
• Polymer invasion
Remedial measures
• Acidization, Clay stabilization , Frac
& Pack , Acidization with foam
based fluids
• Acidization
• Surfactant treatment, Matrix
acidization
12. FORMATION DAMAGE
All wells are susceptible to formation damage to some degree from
relatively minor loss of productivity to complete plugging of specific zones.
Flow surveys invariably show that a high percentage of the zone is open to
the well-bore is not contributing to total flow.
Critical area is always, a few feet away from the well bore.
Contact with foreign fluid is the basic cause of formation damage. This
foreign fluid may be drilling muds, workover fluid, stimulation fluid, or
even the reservoir fluid itself if the original characteristics are altered.
Fluid consists of two: liquid and solids. Either can cause significant
damage to formation through one or several possible mechanisms.
13. FORMATION DAMAGE (continued)
Formation damage is usually caused by the invasion of mud solids & mud
filtrate in to the formation well drilling, completion, workover, water
injection operations.
Formation damage chacterized by low porosity and low permeability with
significant presence of swelling and migrating clays.
Plugging associated with solids:
• Weighing materials, Viscosity builders, Drilled solids, Cement particles,
Lost circulation materials, Pipe dope, Precipitated scales,
• Clays, Fluid loss control materials, Perforating charge debris, Rust and mill
scale, Un-dissolved salt, Fines, Asphaltenes.
14. Physical mechanism:
Physical mechanism where formation can be damaged when pores
and pore channels become blocked by invading mud solids , fines
migration water blocks, emulsion block or gas block phenomenon.
Chemical mechanism:
Chemical mechanism caused by filtrate-pore fluid and filtrate ,
rock incompatibility, mud additives adsorption, / wettability
alteration of the matrix.
Bacterial mechanism:
o Bacterial growth where bacteria can cause permeability
impairment when produce wastes in the form of precipitates thus
blocking pores and pore channels.
o Formation damage problems can be mitigated by the use of a
properly designed mud system that forms a filter cake with low
porosity and low permeability near the well bore region which is
capable of minimizing the mud solids invasion and filtrate loss in
to formation.
15. Use of Alcohols and Mutual solvents in oil & gas wells
Alcohols and Mutual solvents when used with workover fluids can remove or
prevent water or condensate blocks that restrict production.
Alcohols normally mixed with surfactants to reduce surface tension are
effective at removing these blocks , while mutual solvents act as carriers to
minimize their adsorption on to formation.
Water blocks and or condensate blocks are frequently encountered in gas and
retrograde gas wells. These blocks can be carried by a number of operations:
Pressure drawdown in a retrograde well.
Clean filtered brine kill fluids.
Stimulation fluids.
Shut-in where fluid is allowed to fall back on the perforations.
Normal reservoir pressure decline.
Cross flow
Water coning.
16. After a gas well has produced for a period of time, the formation around the
perforation become very dehydrated. This can result from the rapid expansion
of gas and the flash distillation of liquids in this area of maximum pressure drop.
This mechanism can result in formation of salt deposits around the perforations.
When the dehydrated formation is contacted by fluid, formation minerals
especially clays and salts act like a sponge to strongly imbibe water.
A block can then result when the maximum differential pressure that can be
achieved across the perforations is not sufficient to overcome capillary forces in
the pore channels.
Equation for calculation of differential pressure in capillaries is :
ΔP = Ω 2 cos θ/r
ΔP = Differential pressure dynes/cm2, Ω = Surface tension in dynes/cm2. (ST)
θ = Contact angle, r = Capillary radius.
o As ST of a fluid increases, contact angle is decreased or capillary radius is
decreased, the differential pr required to flow down a pore channel will increase.
o To minimize the fluid blocks, ST should be minimized and contact angle
maximized for that fluid in the formation.
o Alcohols have often been used to remove the fluid blocks. Physical properties of
two alcohols have been shown below.
17. Paraffin & asphaltenes
Paraffin & asphaltenes are constituents of crude oils. Deposits of asphaltene and
wax in surface & down hole equipment are a major problem in production operations
Severity depends upon crude oil production, well depth, formation temp, Pr
drop, and producing procedures.
Any organic deposit associated with crude production is called paraffin or wax.
Paraffin compounds are major components of these deposits, they are frequently
a mixture of wax and asphaltenes.
Significant reasons for wax paraffin deposition:
• Cooling produced by the gas in expanding through an orifice or restriction.
• Cooling produced as a result of gas expansion forcing the oil ….
• Cooling produced by radiation of heat from the oil and gas to the surrounding
formations as it flows from the bottom of the well to the surface,.
• Cooling produced by dissolved gas being liberated from the system. Change in
temperature produced by water intrusion.
• Evaporation of the lighter constituents when there is increase in temp.
• Paraffin characteristics & asphaltenes vary significantly from reservoir to reservoir.
• Cross-flow.
18. Paraffin & asphaltenes
Paraffin & asphaltenes differ significantly in chemical structure.
Paraffins are normal (straight chain) or branched alkalines of relatively
high molecular weight and represented by Cn H2n+2
This type of hydrocarbons, inert to chemical reaction and therefore
resistant to attack by acids or bases.
Paraffin deposit also contain asphaltenes, resins, gums, crude oils and
inorganic matter such as fine sand, silt, clays, salt, scales and water.
Asphaltenes are black components present in the crude oil. Molecular
weight is relatively high. They are normally polar chemicals because of the
presence of sulfur, oxygen, nitrogen and various metals in their
molecular structure.
Asphaltenes consist of polycyclic, condensed, aromatic ring compounds.
They are soluble in aromatic solvents such as benzene, toluene, xylene,
Carbon tetrachloride and carbon disulfide but they are not soluble in
distillates such as kerosene and diesel oil. They are also insoluble in other
low molecular weight hydrocarbons such as propane, butane.
Cloud point is to be measured during early stages of crude oil production.
19. Paraffin & asphaltenes
Asphaltenes
1. Melts slowly gradually softening
to a thick viscous fluid.
2. High viscosity fluids.
3. Burns with a smokey flame and
leaves thin ash or carbonaceous
ball
Paraffins
1. Melts over a narrow temperature
range
2. Hot Liquid has a low Viscosity.
3. Burns rapidly with less smoke
than asphaltene and leaves little
residue
Removal of wax deposits:
Mechanical
Solvents
Heat
Dispersants
20. Mechanical Removal of wax deposits:
• Scrapers and cutters are extensively used to remove paraffin from tubing.
• These are relatively economical and usually result in less damage to the
formation.
Removal of wax with Solvents:
• Use of solvents most common for removing wax. CCl4 is excellent solvent but
adverse effect on refinery catalysts. Carbon disulfide is also excellent solvent,
but very expensive. Extremely flammable.
• Condensate, kerosene and diesel are commonly used to dissolve paraffin in
wells where asphaltene content of the deposit is very low.
• Asphaltenes are not soluble in straight chain hydrocarbons such as kerosene,
diesel oil and most condensates. However some condensates contain aromatic
components enables them to dissolve asphaltic deposits.
• Aromatic chemicals such as toluene and xylene are excellent solvents for
asphaltene and paraffin deposits.
• Solvent application must be adopted to suit well conditions. Soaking of the
solvent over a period of time will usually dissolve the solvent.
• Severe paraffin build up in the tubing of rod pumping wells often makes rod
removal very difficult. Pumping a solvent down the tubing soften paraffin and
facilitates rod pulling.
21. Use of Heat for Removal of Wax:
Hot oiling is one of the most popular methods of paraffin removal.
Paraffin is dissolved and melted by the hot oil. Crude or other oil is
heated to a temp significantly greater than that of the formation. Hot
oil is normally pumped down the casing and up the tubing.
Hot oiling can cause the plugging of the formation in wells having a
reservoir temperature of less than 1600 F (710 C). The formation will
cool the hot oil causing paraffin to be deposited in pores of the rock.
Paraffin deposits frequently contain scales and formation fines that
are released when paraffin is dissolved or melted. Well productivity
can be reduced if these solids are forced into formation.
Steam has also been used to melt paraffin or asphaltene in the flow
lines, tubing, casing, well bore or formation.
Any application of heat to remove paraffin should be carried out
before large deposits have accumulated. The use of hot oil at regular
interval has proved to be effective.
22. Removal Wax Using Dispersants:
Water soluble dispersants can be used to remove paraffin
deposits. Chemical concentrations (2-10%) water soluble
dispersant are generally used to remove paraffin removal.
It does not remove paraffin but disperses paraffin particles, to
be circulated from the well.
In low pressure wells, the dispersant solution may be injected
down the annulus and then pumped with oil production.
When paraffin is very hard and dense , soaking period of 3-4
hours is suggested prior to returning the well to production.
Surface lines can also be cleaned by circulating dispersant
through the system.
Pour point Depressors: (PPD)
PPD is generally used on the surface for flow assurance from the
process station till oil reaches to refinery.
23. Surfactants for well Treatments
Surfactants are chemicals that can favorably or un-favorably affect the
flow of fluids near the well bore .
Chemically a surfactant has an affinity for both water and oil. The
surfactant molecule is partially soluble both in water and oil.
Surfactants can bring the following changes of reservoir fluids reservoir:
Raise or lower surface and interfacial tension
Make, break, weaken or strengthen an emulsion.
Change the wettability of reservoir rocks and casing, tubing.
Disperse or flocculate clays and other fines.
Surfactants can also reduce interfacial tension between two immiscible
liquids by adsorbing.
24. Surfactants for well Treatments
Wettability is a descriptive term used to indicate whether a rock or
metal surface has the capacity to be preferentially coated with a film
of oil or a film of water.
Surfactants may adsorb at the interface between the liquid and rock
or metal surface and may change the electrical charge on the rock or
metal there by altering the wettability.
Sand and clays are water wet and have a negative surface charge.
Lime stone and dolomite are water wet and have a positive surface
charge in the pH range of 0-8
Non ionic surfactants are the most versatile of the surfactants, used to
lower the surface tension, prevent damage and stimulate the well.
Non ionic surfactants do not carry a charge and therefore compatible
with most other chemicals being used in production operations.
Non ionic surfactants are more soluble at lower temperature,
however they are more prone to come out of solution at an elevated
temperatures forming insoluble miscelles visible as a cloud point
25. Surfactants for well Treatments
Types of damage that are prevented, alleviated or aggravated by surfactant
o Oil wetting of formation rock
o Water blocks
o Viscous emulsion blocks
o Interfacial film or membrane blocks
o Particle blocks caused by dispersion , flocculation or movement of clays.
o Flow restriction caused by high surface or interfacial tension of liquid.
Oil wetting of formation rock: Sources of oil wetting in oil & gas wells:
• Surfactant in drilling mud filtrates, workover or well stimulation fluids
may oil wet the formation.
• Corrosion inhibitors and bactericides are usually cationic surfactants
which will oil wet sand stone and clay.
• Stock tank or heater treater emulsion breakers are cationics which will
oil wet sand and clay.
• Oil base mud containing blown asphalt will oil wet sand stone. Filtrates
from oil emulsion muds usually contain considerable cationic surfactants
which will oil wet sand stone and clays.
26. Surfactants for well Treatments
Water Blocks:
When large quantities of water are lost to a partially oil–wet
formation, the return of original oil or gas productivity may be very
slow especially in partially depleted reservoirs.
It is caused by temporary reduction of relative permeability near the
well bore to oil or gas.
Water blocking can be prevented by adding about 0.1to 0.2 % by
volume of surfactant selected to lower surface and interfacial
tension, water wet the formation and prevent emulsions.
Clean up of a water blocked well can be accelerated by injecting in to
the formation solution of 1% to 3% by volume of selected surfactant
in clean compatible water or oil.
The surfactant should lower the surface and interfacial tension and
leave the formation in a water wet condition.
It requires many times the volume of surfactant to prevent or remove
the formation damage.
27. Surfactants for well Treatments
Interfacial Films or Membranes:
Film forming material including surfactants can be adsorbed at the
oil- water interface and cause formation plugging.
Interfacial films are related to oil wetting and emulsion properties of
crude. Fines, clays and asphaltenes increase film strength.
An increase in percent salt in a solution increase film strength. Oil
exposed to air may form tough films. Specific surfactant may also
increase film strength in a particular oil-water system.
The use of solvent as a carrier for surfactant is usually beneficial in
removing tough films.
28. Emulsion Block:
Various emulsions of oil and water in the formation near well bore can
drastically reduce the productivity of oil and gas wells.
Emulsions in the formation can be broken by injecting demulsifying
surfactants into the formation provided intimate contact is made
between the surfactant and each emulsion droplet.
Breaking emulsion in the formation usually require injection of 2-3% by
volume of demulsifying surfactant in clean compatible water or clean
oil.
Diagnosis of Emulsion block:
If the calculated average well permeability as determined by the
injectivity tests is more than the average permeability determined from
the production tests, then it can be attributed to emulsion blocks.
It is frequently called check valve effect.
If an emulsion blocked well is producing water, increasing or decreasing
rates will not appreciably change the water percentage.
29. Particle Block:
It is desirable to maintain formation clays in the original condition in the
reservoir, but an oil or gas formation may be blocked by transmission of
clays into the formation in water or oil or mud filtrate.
Dispersing flocculating, breaking loose or moving clays causes more
damage to wells than the swelling of clays.
Dispersion of clays: Diagnosis of emulsion block:
• Clay dispersion is a frequent cause of formation damage. A non-ionic
surfactants will disperse clays in acid solution. High pH fluids tends to
disperse clays.
• High concentrations of same surfactants may damage the formation by
dispersing clays in to formation.
Flocculation of clays:
o Clay flocculation may sometimes reduce or increase formation damage.
o Specific non ionic surfactants may be used to flocculate clays.
o Acid and other low pH fluids tend to flocculate clays.
30. Change of Particle Size:
• Oil wetting clays with cationic surfactants increase the size of clay
particles and there by increase the severity of clay blocking.
• Cationic surfactants are difficult to remove from clays and sand; use of
cationic surfactants should be avoided in sandstone reservoirs.
• A mutual solvent preflush may prevent cationic adsorption on clays, sands
• Anionic surfactant should always be used when acidizing sandstone with
HCl to prevent clay flocculation as well as to prevent emulsions and to
increase water wettability of the formation.
• Lowering surface and interfacial tension will aid in preventing emulsion
and water blocks and will accelerate well cleanup.
• Proper use of surfactant during well completion can prevent many types
of damage and result in increased productivity.
• A correct surfactant which is designed for specific well conditions can
lower surface and interfacial tension, favorably change wettability, break
or prevent emulsions, prevent or remove water blocks, cause clays to
disperse, flocculate or remain in place as desired
31. Susceptibility to surfactant related damage:
Organic corrosion inhibitors and bactericides are cationic
surfactants. Before squeezing any cationic corrosion inhibitor into
sandstone, lab testes should be run on cores to determine the effect
of specific corrosion inhibitor on formation permeability.
Caution must be exercised in using salt water or oil from treaters or
field stock tanks treated with cationic surfactant emulsion breakers.
The damage effects of cationic surfactant may be overcome by
adding selected surfactants or mutual solvents.
Crude containing more than 1% asphaltene are prone to formation
damage that is amenable to surfactant and solvent stimulation.
Low API gr crude usually contains a high asphaltenes. Sandstone
wells producing low gr crudes are more susceptible to formation
damage from oil wetting, emulsion blocking, and water blocking.
24-72 hour solvent surfactant soak followed by HF acid treatment is
usually best treatment for wells.