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Low Salinity Waterflooding To Improve Oil Recovery Historical Field Evidence
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Book Synopsis Low-Salinity Waterflooding to Improve Oil Recovery - Historical Field Evidence by :
Download or read book Low-Salinity Waterflooding to Improve Oil Recovery - Historical Field Evidence written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Waterflooding is by far the most widely applied method of improved oil recovery. Crude oil/brine/rock interactions can lead to large variations in the displacement efficiency of wa-terfloods. Laboratory water-flood tests and single-well tracer tests have shown that injection of dilute brine can increase oil recovery, but work designed to test the method on a field scale has not yet been undertaken. Historical waterflood records could unintentionally provide some evidence of improved recovery from waterflooding with lower salinity brine. Nu-merous fields in the Powder River basin of Wyoming have been waterflooded using low salinity brine (about 500 ppm) obtained from the Madison limestone or Fox Hills sandstone. Three Minnelusa formation fields in the basin were identified as potential candidates for waterflood comparisons based on the salinity of the connate and injection water. Historical pro-duction and injection data for these fields were obtained from the public record. Field waterflood data were manipulated to be displayed in the same format as laboratory coreflood re-sults. Recovery from fields using lower salinity injection wa-ter was greater than that using higher salinity injection wa-ter--matching recovery trends for laboratory and single-well tests.
Book Synopsis Coreflooding Oil Displacements with Low Salinity Brine by : Scott Michael Rivet
Download or read book Coreflooding Oil Displacements with Low Salinity Brine written by Scott Michael Rivet and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Waterflooding is applied worldwide to improve oil recovery. Evidence of enhancement in waterflood efficiency by injecting low salinity brine has been observed in the laboratory and in the field. The technology is of considerable interest because of its simplicity and its low cost. In this work, laboratory corefloods were conducted to study the effect of low salinity waterflooding on oil recovery rate, residual oil saturation and relative permeability. Evidence of low salinity enhanced oil recovery was observed some of these corefloods. Improved oil recovery was generally accompanied by an increase in water-wetness, based on an observed decrease in end-point water relative permeability and an increase in end-point oil relative permeability. Injecting low salinity brine produced a persistent wettability alteration that eliminated oil recovery salinity dependence in subsequent floods. However, the sensitivity to salinity was restored by re-aging the core with the same oil. Tertiary low salinity recovery reported by other researchers was never observed. Low salinity waterflooding produced no oil recovery benefit in cores that were initially strongly water-wet. Based on these results, a working hypothesis is that injecting low salinity brine induces a wettability alteration from mixed-wet to water-wet in some cores and that this change improves the oil recovery. More experiments are needed both to identify the characteristics of the cores that are favorable for low salinity enhanced oil recovery and to better understand and quantify the mechanism.
Download or read book Core Analysis written by Colin McPhee and published by Elsevier. This book was released on 2015-12-10 with total page 853 pages. Available in PDF, EPUB and Kindle. Book excerpt: Core Analysis: A Best Practice Guide is a practical guide to the design of core analysis programs. Written to address the need for an updated set of recommended practices covering special core analysis and geomechanics tests, the book also provides unique insights into data quality control diagnosis and data utilization in reservoir models. The book's best practices and procedures benefit petrophysicists, geoscientists, reservoir engineers, and production engineers, who will find useful information on core data in reservoir static and dynamic models. It provides a solid understanding of the core analysis procedures and methods used by commercial laboratories, the details of lab data reporting required to create quality control tests, and the diagnostic plots and protocols that can be used to identify suspect or erroneous data. Provides a practical overview of core analysis, from coring at the well site to laboratory data acquisition and interpretation Defines current best practice in core analysis preparation and test procedures, and the diagnostic tools used to quality control core data Provides essential information on design of core analysis programs and to judge the quality and reliability of core analysis data ultimately used in reservoir evaluation Of specific interest to those working in core analysis, porosity, relative permeability, and geomechanics
Book Synopsis Data Analysis of Low-salinity Waterflooding to Enhance the Oil Recovery in Sandstone Reservoirs by : Nadia Ariani
Download or read book Data Analysis of Low-salinity Waterflooding to Enhance the Oil Recovery in Sandstone Reservoirs written by Nadia Ariani and published by . This book was released on 2018 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The lack of a single reasonable general mechanism to describe how low-salinity waterflooding can improve oil recovery in both laboratory and field pilot projects has increased the interests of many researchers and stakeholders. There has not been observed the relationship of formation brine salinity and injected brine salinity to see how much salinity is reduced to produce the maximum enhanced oil recovery by LSWF. There is no guidance in what EOR stage the LSWF is best implemented. This work collects data from various published literature to develop a comprehensive data set regarding low-salinity waterflooding in sandstone reservoirs. The LSWF mechanisms are discussed to gain better understanding of the LSWF effect on oil recovery in sandstone reservoirs. The data set consists of parameters from coreflooding experiments that involved core samples, crude oil, and brines from different places. Histograms and box plots are used to visualize various kinds of data, and cross plots and charts are used to analyze the relationship between the important parameters and oil recovery. This study revealed the complexity of LSWF mechanisms and the corresponding parameters in the COBR system that associate with this process. The effects of rock porosity and permeability, total clay content, core aging temperature, COBR wettability, initial water saturation, oil base/acid ratio, asphaltenes content, formation and injected brine salinity and composition on the enhanced oil recovery are discussed in both secondary and tertiary LSWF modes. The applicability of parameters affecting the LSWF process are summarized. It is also observed the relationship between formation brine salinity and how much injected brine salinity was reduced or diluted to produce the maximum incremental secondary and additional tertiary recovery. Finally, in comparison to the conventional waterflooding, the final recovery from all of the LSWF stages are higher than the one of the conventional waterflooding, and the secondary+tertiary EOR stage produces the highest final recovery"--Abstract, page iii.
Book Synopsis Enhanced Oil Recovery Field Case Studies by : Tor Austad
Download or read book Enhanced Oil Recovery Field Case Studies written by Tor Austad and published by Elsevier Inc. Chapters. This book was released on 2013-04-10 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water flooding of oil reservoirs has been performed for a century in order to improve oil recovery for two reasons: (1) give pressure support to the reservoir to prevent gas production and (2) displace the oil by viscous forces. During the last 30 years, it was discovered that the wetting properties of the reservoir played a very important role for the efficiency of the water flood. Even though much work have been published on crude oil–brine–rock (CBR) interaction related to wetting properties, Professor N.R. Morrow, University of Wyoming, asked the audience the following question at the European enhanced oil-recovery (EOR) meeting in Cambridge, April 2011: Do we understand water flooding of oil reservoirs? If we are not able to explain why injection fluids of different ionic composition can have a great impact on displacement efficiency and oil recovery, the answer to Morrow’s question is NO. Researchers have to admit that we do not know the phenomena of water flooding well enough. The key to improve our understanding is to obtain fundamental chemical understanding of the CBR interaction by controlled laboratory studies, and then propose chemical mechanisms, which should be validated also from field experience. In this chapter, I have tried to sum up our experience and chemical understanding on water-based EOR in carbonates and sandstones during the last 20 years with a specific focus on initial wetting properties and possibilities for wettability modification to optimize oil recovery. Chemically, the CBR interaction is completely different in carbonates and sandstones. The proposed chemical mechanisms for wettability modification are used to explain field observations.
Book Synopsis Formation Damage during Improved Oil Recovery by : Bin Yuan
Download or read book Formation Damage during Improved Oil Recovery written by Bin Yuan and published by Gulf Professional Publishing. This book was released on 2018-05-31 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Formation Damage during Improved Oil Recovery: Fundamentals and Applications bridges the gap between theoretical knowledge and field practice by presenting information on formation damage issues that arise during enhanced oil recovery. Multi-contributed technical chapters include sections on modeling and simulation, lab experiments, field case studies, and newly proposed technologies and methods that are related to formation damage during secondary and tertiary recovery processes in both conventional and unconventional reservoirs. Focusing on both the fundamental theories related to EOR and formation damage, this reference helps engineers formulate integrated and systematic designs for applying EOR processes while also considering formation damage issues. Presents the first complete reference addressing formation damage as a result of enhanced oil recovery Provides the mechanisms for formation damage issues that are coupled with EOR Suggests appropriate preventative actions or responses Delivers a structured approach on how to understand the fundamental theories, practical challenges and solutions
Book Synopsis Low Salinity and Engineered Water Injection for Sandstone and Carbonate Reservoirs by : Emad Walid Al Shalabi
Download or read book Low Salinity and Engineered Water Injection for Sandstone and Carbonate Reservoirs written by Emad Walid Al Shalabi and published by Gulf Professional Publishing. This book was released on 2017-06-14 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low Salinity and Engineered Water Injection for Sandstone and Carbonate Reservoirs provides a first of its kind review of the low salinity and engineered water injection (LSWI/EWI) techniques for today’s more complex enhanced oil recovery methods. Reservoir engineers today are challenged in the design and physical mechanisms behind low salinity injection projects, and to date, the research is currently only located in numerous journal locations. This reference helps readers overcome these challenging issues with explanations on models, experiments, mechanism analysis, and field applications involved in low salinity and engineered water. Covering significant laboratory, numerical, and field studies, lessons learned are also highlighted along with key areas for future research in this fast-growing area of the oil and gas industry. After an introduction to its techniques, the initial chapters review the main experimental findings and explore the mechanisms behind the impact of LSWI/EWI on oil recovery. The book then moves on to the critical area of modeling and simulation, discusses the geochemistry of LSWI/EWI processes, and applications of LSWI/EWI techniques in the field, including the authors’ own recommendations based on their extensive experience. It is an essential reference for professional reservoir and field engineers, researchers and students working on LSWI/EWI and seeking to apply these methods for increased oil recovery. Teaches users how to understand the various mechanisms contributing to incremental oil recovery using low salinity and engineering water injection (LSWI/EWI) in sandstones and carbonates Balances guidance between designing laboratory experiments, to applying the LSWI/EWI techniques at both pilot-scale and full-field-scale for real-world operations Presents state-of-the-art approaches to simulation and modeling of LSWI/EWI
Book Synopsis Modeling the Effect of Injecting Low Salinity Water on Oil Recovery from Carbonate Reservoirs by : Emad W. Al Shalabi
Download or read book Modeling the Effect of Injecting Low Salinity Water on Oil Recovery from Carbonate Reservoirs written by Emad W. Al Shalabi and published by Emad W. Al Shalabi. This book was released on 2014 with total page 697 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low salinity water injection technique (LSWI) has become one of the important research topics in the oil industry because of its possible advantages for improving oil recovery. Several mechanisms describing the LSWI process have been suggested in the literature; however, there is no consensus on a single main mechanism for the low salinity effect on oil recovery. As a result of the latter, there are few models for LSWI and especially for carbonates due to their heterogeneity and complexity. In this research, we proposed a systematic approach for modeling the LSWI effect on oil recovery from carbonates by proposing six different methods for history matching and three different LSWI models for the UTCHEM simulator, empirical, fundamental, and mechanistic LSWI models. The empirical LSWI model uses contact angle measurements and injected water salinity. The fundamental LSWI model captures the effect of LSWI through the trapping number. In the mechanistic LSWI model, we include the effect of different geochemical reactions through Gibbs free energy. Moreover, field-scale predictions of LSWI were performed and followed by a sensitivity analysis for the most influential design parameters using design of experiment (DoE). The LSWI technique was also optimized using the response surface methodology (RSM) where a response surface was built. Also, we moved a step further by investigating the combined effect of injecting low salinity water and carbon dioxide on oil recovery from carbonates through modeling of the process and numerical simulations using the UTCOMP simulator. The analysis showed that CO2 is the main controller of the residual oil saturation whereas the low salinity water boosts the oil production rate by increasing the oil relative permeability through wettability alteration towards a more water-wet state. In addition, geochemical modeling of LSWI only and the combined effect of LSWI and CO2 were performed using both UTCHEM and PHREEQC upon which the geochemical model in UTCHEM was modified and validated against PHREEQC. Based on the geochemical interpretation of the LSWI technique, we believe that wettability alteration is the main contributor to the LSWI effect on oil recovery from carbonates by anhydrite dissolution and surface charge change through pH exceeding the point of zero charge.
Book Synopsis Improved Oil Recovery by Sequential Waterflooding and by Injection of Low Salinity Brine by : Nina Loahardjo
Download or read book Improved Oil Recovery by Sequential Waterflooding and by Injection of Low Salinity Brine written by Nina Loahardjo and published by . This book was released on 2009 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Waterflooding is by far the most commonly applied method of increasing oil recovery over that given by primary production. Reservoir wettability has been shown to be a key factor in determining the microscopic displacement efficiency in the swept regions of a waterflood. Reservoir wettability depends on complex crude oil/brine/rock (COBR) interactions. Numerous laboratory investigations and a growing number of pilot field studies show that oil recovery can be improved by injection of low salinity brine. This thesis includes study of the effect of low salinity flooding on oil recovery for selected reservoirs. Observations on the reproducibility of oil recovery behavior led to development of a new approach to improved oil recovery based on repeated waterflooding without change in brine composition. Laboratory studies indicated that the presence of the crude/oil interface was essential to oil recovery by sequential waterflooding. Crude properties have been measured for 27 crude oils. The oils were characterized according to density, viscosity, refractive index, surface tension, acid and base numbers, composition and vapor pressure. The effects of pH and salinity on interfacial tension were determined for a wide range of crude oils derived from both sandstone and carbonate reservoirs. A large majority of the oils exhibited low interfacial tensions at both low and high pH. For the selected COBR reservoir combinations, increase in oil recovery by low salinity waterflooding was often, but not always observed. The cost of recovering cores from a reservoir is very high. Furthermore, reservoir heterogeneity often limits the number of core samples that can be used in duplicate experiments. After testing, reservoir cores were therefore cleaned and reused. For a core that showed large response to reduction in injection brine salinity, it was found that the initial recovery, first measured for seawater, could not be reproduced, with recovery still being close to that given by the brine of lowest salinity. As a test of reproducibility, cores that had been waterflooded with high salinity brine were taken back to initial water saturation by oil flooding and re-flooded without change in the injection brine composition. For 15 out of 18 tests that included both sandstone and limestone, residual oil saturation decreased from one flood to the next. Reductions in residual oil saturation were not observed for recovery of refined oil. Material balances for sequential flooding were checked against Dean-Stark extraction and by tracer tests. The overall trend of reduction in residual oil saturation was confirmed by MRI imaging of changes in saturation distribution during sequential floods. Further investigation of this new approach to tertiary recovery is proposed through relatively low-cost single-well field tests.
Book Synopsis Novel Insights Into Low Salinity Water Flooding Enhanced Oil Recovery in Sandstone Reservoirs by : Hasan N. Al-Saedi
Download or read book Novel Insights Into Low Salinity Water Flooding Enhanced Oil Recovery in Sandstone Reservoirs written by Hasan N. Al-Saedi and published by . This book was released on 2019 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Ever growing global energy demand and the natural decline in oil production from mature oil fields have been the main incentives to search for methods to increase recovery efficiency for several decades. Water flooding is extensively applied worldwide to improve oil recovery. The recent drop in oil prices has turned the oil industry to the cheapest improved oil recovery (IOR) techniques, such as low salinity (LS) waterflooding. Also, the reduction in reservoir energy and the friendly environmental aspects of low salinity water flooding (LSWF) provide additional incentives for its use. That LS water requires decreasing only the active divalent cations such as Ca2+, Mg2+ and water salinity makes LS water flooding a relatively simple and low expense IOR technique. The water chemistry significantly impacts the oil recovery factor. Wettability is one of the major parameters that control the efficiency of water flooding. The primary mechanism for increased oil recovery during LSWF in both sandstone and carbonate reservoirs is wettability alteration of the rock surface from oil-wet to water-wet. LS water imbibed into the low water-wet zones, the water wetness of the rock increased after injecting LS water, and in turn, microscopic sweep efficiency enhanced too. The mechanism behind LS water flooding has been extensively investigated in the literature but it still a topic of debate. The objective of this research is to solve the controversy and show the following: (1) Water chemistry weather partially or strongly determines the dominant wettability alteration mode. (2) The role of divalent cations in the formation water and in the injected water. (3) Clay's role for incremental recovery. This research work seeks to quantify the effects of mineral composition and water chemistry on water-rock interactions and wettability alteration"--Abstract, page
Book Synopsis Colloids and Interfaces in Oil Recovery by : Spencer Taylor
Download or read book Colloids and Interfaces in Oil Recovery written by Spencer Taylor and published by MDPI. This book was released on 2019-06-21 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well-known that colloid and interface science and petroleum production are inextricably linked. Whether in the reservoir, with its porous structure, or during recovery, crude oil is intimately associated with rock surfaces and with water, often in the form of emulsions. This situation leads to highly complex systems, comprising multiple colloids and interfaces, which require to be optimized if oil is to be recovered efficiently, both in terms of economic cost and with due concern for the environment. This book contains a compilation of contemporary research topics which illustrate various aspects of the importance of colloids and interfaces in crude oil recovery through modifying conditions between the rock, crude oil, and water in the reservoir, in order to achieve improved oil recovery. The specific topics covered relate both to conventional oils, in which waterflooding is the most common secondary and tertiary means of recovery, and to non-conventional heavy oil and natural bitumen, which require thermal recovery methods, owing to their high viscosity.
Book Synopsis Efficiency of Low Salinity Polymer Flooding in Sandstone Cores by : Chie Kozaki
Download or read book Efficiency of Low Salinity Polymer Flooding in Sandstone Cores written by Chie Kozaki and published by . This book was released on 2012 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Waterflooding has been used for many decades as a way of recovering oil from petroleum reservoirs. Historically the salinity of the injection water has not been regarded as a key variable in determining the amount of oil recovered. In recent years, however, evidence of increased oil recovery by injection of low salinity water has been observed in laboratories and fields. The technique is getting wider attention in the oil industry because it is more cost-effective than other EOR techniques. The present work demonstrates the synergy of low salinity water flooding and polymer flooding in the laboratory scale. The use of low salinity polymer solution in polymer flooding has significant benefits because considerably lower amount of polymer is required to make the solution of a target viscosity. Low salinity polymer flooding can also increase oil recovery by lowering residual oil saturation and achieve faster oil recovery by improving sweep efficiency. Several coreflood experiments were conducted to study the efficiency of low salinity water flooding and low salinity polymer flooding in mixed-wet Berea sandstone cores. All the core samples were aged with a crude oil at 90oC for 30-60 days before the tests. All the polymer floods were conducted in the tertiary mode. A synthetic formation brine (33,800 ppm) was chosen for high salinity water and a NaCl brine (1,000 ppm) for low salinity water. Medium molecular weight HPAM polymer, FlopaamTM 3330S was used due to the low/moderate permeability of the Berea sandstone cores used in this study. Coreflood tests indicate that injection of low salinity polymer solution reduces residual oil saturation by 5-10% over that of the high salinity waterflood. A part of the residual saturation reduction is due to low salinity and this reduction is achieved in less pore volumes of injection in the presence of polymers. Effluent ion analysis from both low salinity water flooding and low salinity polymer flooding showed a slight increase in divalent cation concentrations after the polymer breakthrough. Cation bridging may play a role in oil wettability and low salinity injection desorbs some of these cations.
Book Synopsis Flow and Transport Properties of Unconventional Reservoirs 2018 by : Jianchao Cai
Download or read book Flow and Transport Properties of Unconventional Reservoirs 2018 written by Jianchao Cai and published by MDPI. This book was released on 2019-07-23 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unconventional reservoirs are usually complex and highly heterogeneous, such as shale, coal, and tight sandstone reservoirs. The strong physical and chemical interactions between fluids and pore surfaces lead to the inapplicability of conventional approaches for characterizing fluid flow in these low-porosity and ultralow-permeability reservoir systems. Therefore, new theories and techniques are urgently needed to characterize petrophysical properties, fluid transport, and their relationships at multiple scales for improving production efficiency from unconventional reservoirs. This book presents fundamental innovations gathered from 21 recent works on novel applications of new techniques and theories in unconventional reservoirs, covering the fields of petrophysical characterization, hydraulic fracturing, fluid transport physics, enhanced oil recovery, and geothermal energy. Clearly, the research covered in this book is helpful to understand and master the latest techniques and theories for unconventional reservoirs, which have important practical significance for the economic and effective development of unconventional oil and gas resources.
Book Synopsis Low Salinity Water Flooding Application on Different Reservoir Rock Types by : mohamed magdy
Download or read book Low Salinity Water Flooding Application on Different Reservoir Rock Types written by mohamed magdy and published by محمد مجدي. This book was released on with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface chemistry has a great effect in enhancing oil recovery. For oil-wet sandstone reservoirs, low salinity waterflooding (LSWF) is effective as it can alter rock wettability and reduce the oil/water interfacial tension. LSWF application is related to rock’s clay content and type. Clay hydrocarbon bonding can be formed through many mechanisms such as van deer waals forces and ionic bridge. LSWF effect is to weaken these bonds through two main mechanisms, Double Layer Expansion (DLE) and Multicomponent Ionic Exchange (MIE). Two fields (S and D), in Egypt’s Western Desert, have depleted strongly oil-wet reservoirs with similar rock and fluid properties. Field (S) is flooded by low salinity water (LSW), while Field (D) is flooded by high salinity water (HSW). Fortunately, the water source for Field (S) flooding is a LSW zone, which has a salinity +/- 5000 ppm as total dissolved solids (TDS). The formation water salinity was +/- 25,000 ppm as TDS. Field (S) lab experiments showed good compatibility between injected LSW, formation water and rock minerals. XRD and SEM indicate calcareous cementation with detrital clays content around 5%. Kaolinite is the common clay type, which has a low cation exchange capacity. For Field (S), the estimated ultimate recovery (EUR) is 46%, while EUR for Field (D) is 39%. One of the main causes of this increase in Field (S) is LSWF application.
Book Synopsis Recovery of Crude Oil from Outcrop and Reservoir Sandstone by Low Salinity Waterflooding by : Hui Pu
Download or read book Recovery of Crude Oil from Outcrop and Reservoir Sandstone by Low Salinity Waterflooding written by Hui Pu and published by . This book was released on 2010 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of Enhanced Oil Recovery (EOR) technologies cannot be overemphasized, especially in the context of the surge in energy demand driven by rapid economic growth in developing countries as people strive to improve their living standards. Getting higher oil recovery from existing fields will be a key part of meeting the world's growing demand for energy. In the past decade, injection of brines of low salinity content and selected ionic composition in sandstone reservoirs has been developed into an emerging EOR technology. The advantage of low salinity waterflooding is that it is operationally comparable to conventional waterflooding and does not require expensive chemicals or carbon dioxide and nitrogen. The complexity of the crude oil/brine/rock interactions is well recognized and the mechanisms behind the low salinity EOR process have been debated in the literature for the last decade. The objective of this work is to explore by experimental study the effect of low salinity waterflooding on different outcrop and reservoir cores. Investigation of increased oil recovery by injection of low salinity water such as coalbed methane production water has been extended to reservoir cores from the Tensleep, Minnelusa and Phosphoria formations in Wyoming and outcrop cores (Berea and Bentheim). The Tensleep and Minnelusa formations are eolian sandstones of comparable depositional environment that contain interstitial anhydrite, dolomite and occasional calcite cements. The Phosphoria dolomite has pin-point to coarse vuggy pores lined by sparry dolomite crystals and also features patches of anhydrite. All the cores taken from pay zones showed increased oil recovery ranging from 5 to 8% original oil in place through injection of low salinity water. Increase in sulfate ion content of the effluent brine confirmed the dissolution of anhydrite, for all three reservoir rock types. Proposed mechanisms of recovery by low salinity flooding of sandstones which are tied to the presence of clay cannot apply because none of these rocks have significant clay content. Further evidence of the role of anhydrite dissolution was provided by the recovery behavior of Tensleep cores taken from the water-saturated aquifer zone of an oil reservoir. Anhydrite cement was sparse and only visible in occluded regions of pore space but not in regions that were clearly permeable. For these cores, there was no additional oil recovery when the injected brine was switched to low salinity water. The release of dolomite crystals and other fine embedded minerals which is likely associated with dissolution of anhydrite, may be a factor in the observed response to low salinity waterflooding. The movement of cement components is a possible contributing factor in the wide variety of observed relationships between pressure drop and oil recovery. For example, significant variation of relative permeability to brine at constant saturation is often observed.
Book Synopsis Potential of Low-Salinity Waterflooding Technology to Improve Oil Recovery by : Hisham Ben Mahmud
Download or read book Potential of Low-Salinity Waterflooding Technology to Improve Oil Recovery written by Hisham Ben Mahmud and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-salinity waterflooding (LSWF) is a potential new method for enhanced oil recovery (EOR) in sandstone and carbonate rock formations. LSWF approach has gained an attention in the oil and gas industry due to its potential advantages over the conventional waterflooding and other chemical EOR technologies. The efficiency of waterflooding process is effected via reservoir and fluid parameters such as formation rock type, porosity, permeability, reservoir fluid saturation and distribution and optimum time of water injection. Combined effect of these factors can define the ultimate recovery of hydrocarbon. The main objective of this chapter is to review the mechanism of LSWF technique in improving oil recovery and the mechanism under which it operates. Various laboratory studies and few field applications of LSWF in recent years have been presented mainly at the lab scale. Also it will explore numerical modeling developments of this EOR approach.
Book Synopsis Modeling the Effect of Injecting Low Salinity Water on Oil Recovery from Carbonate Reservoirs by : Emad W. Al Shalabi
Download or read book Modeling the Effect of Injecting Low Salinity Water on Oil Recovery from Carbonate Reservoirs written by Emad W. Al Shalabi and published by Emad W. Al Shalabi. This book was released on 2014-10-20 with total page 697 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low salinity water injection technique (LSWI) has become one of the important research topics in the oil industry because of its possible advantages for improving oil recovery. Several mechanisms describing the LSWI process have been suggested in the literature; however, there is no consensus on a single main mechanism for the low salinity effect on oil recovery. As a result of the latter, there are few models for LSWI and especially for carbonates due to their heterogeneity and complexity. In this research, we proposed a systematic approach for modeling the LSWI effect on oil recovery from carbonates by proposing six different methods for history matching and three different LSWI models for the UTCHEM simulator, empirical, fundamental, and mechanistic LSWI models. The empirical LSWI model uses contact angle measurements and injected water salinity. The fundamental LSWI model captures the effect of LSWI through the trapping number. In the mechanistic LSWI model, we include the effect of different geochemical reactions through Gibbs free energy. Moreover, field-scale predictions of LSWI were performed and followed by a sensitivity analysis for the most influential design parameters using design of experiment (DoE). The LSWI technique was also optimized using the response surface methodology (RSM) where a response surface was built. Also, we moved a step further by investigating the combined effect of injecting low salinity water and carbon dioxide on oil recovery from carbonates through modeling of the process and numerical simulations using the UTCOMP simulator. The analysis showed that CO2 is the main controller of the residual oil saturation whereas the low salinity water boosts the oil production rate by increasing the oil relative permeability through wettability alteration towards a more water-wet state. In addition, geochemical modeling of LSWI only and the combined effect of LSWI and CO2 were performed using both UTCHEM and PHREEQC upon which the geochemical model in UTCHEM was modified and validated against PHREEQC. Based on the geochemical interpretation of the LSWI technique, we believe that wettability alteration is the main contributor to the LSWI effect on oil recovery from carbonates by anhydrite dissolution and surface charge change through pH exceeding the point of zero charge.
