Evaluation of a Surfactant Carrier for the Effective Propagation and Target Release of Surfactants Within Porous Media During Enhanced Oil Recovery. Part I: Dynamic Adsorption Study

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (12 download)

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Book Synopsis Evaluation of a Surfactant Carrier for the Effective Propagation and Target Release of Surfactants Within Porous Media During Enhanced Oil Recovery. Part I: Dynamic Adsorption Study by :

Download or read book Evaluation of a Surfactant Carrier for the Effective Propagation and Target Release of Surfactants Within Porous Media During Enhanced Oil Recovery. Part I: Dynamic Adsorption Study written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Surfactants for Enhanced Oil Recovery Applications

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Publisher : Springer Nature
ISBN 13 : 3030187853
Total Pages : 135 pages
Book Rating : 4.0/5 (31 download)

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Book Synopsis Surfactants for Enhanced Oil Recovery Applications by : Muhammad Sagir

Download or read book Surfactants for Enhanced Oil Recovery Applications written by Muhammad Sagir and published by Springer Nature. This book was released on 2020-01-29 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise treatise on the use of surfactants in enhanced oil recovery (EOR), including information on key types of surfactants and their respective applications in the wider petroleum industry. The authors discuss carbon dioxide EOR, alkaline-surfactant-polymer flooding strategies, and the use of surfactants as a means of reducing interfacial tension, while also paying special attention to the challenges involved in using surfactants for enhanced oil recovery, such as the difficult issue of surfactant adsorption on reservoir rock. All chapters highlight and are based on the authors’ own laboratory-scale case studies. Given its content, the book offers a valuable asset for graduate students of petroleum and chemical engineering, as well as researchers in the field of chemical enhanced oil recovery. It will also be of interest to professionals involved in enhanced industrial oil recovery.

Multi-scale Investigations of the Impact of Surfactant Structure on Oil Recovery from Natural Porous Media

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ISBN 13 : 9780438886384
Total Pages : 181 pages
Book Rating : 4.8/5 (863 download)

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Book Synopsis Multi-scale Investigations of the Impact of Surfactant Structure on Oil Recovery from Natural Porous Media by : Vahideh Mirchi

Download or read book Multi-scale Investigations of the Impact of Surfactant Structure on Oil Recovery from Natural Porous Media written by Vahideh Mirchi and published by . This book was released on 2018 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study aims at establishing structure-function relationships relevant to surfactant-based enhanced oil recovery (EOR) under different wettability conditions. We present the results of an extensive, multi-scale experimental study designed to probe the effects of surfactant molecular structure on oil displacement in sandstone and carbonate rock samples. Initially a new framework was developed to methodically characterize the effect of surfactants on fundamental parameters governing fluid displacement in brine/oil/tight rock systems at reservoir conditions. For that, we present a detailed methodology for measuring the interfacial properties of these systems, including rock substrate preparation, thin needle utilization, fluid pre-equilibration, in-line density measurements, all of which are critically important due to surfactant partitioning in brine and oil phases. The experimental framework was first validated with simple ultra-low IFT systems using the rising/captive bubble technique, then the effect of pressure, temperature, surfactant concentration, and brine chemistry on IFT and CA were investigated in a systematic manner. Subsequently, the framework was used to examine the effect of hydrophobic and hydrophilic chain lengths of polyoxyethylenated nonionic surfactants on dynamic interfacial properties in porous media. It included comprehensive experimental examination of phase behavior, cloud point temperature, dynamic interfacial tension, dynamic contact angle, and spontaneous and forced imbibitions at ambient and reservoir conditions. This resulted in development of a new insight that relates the speed by which surfactants reduce interfacial tension to oil-brine displacement efficiency. This relationship was reconfirmed by examining pore-fluid occupancies generated through surfactant imbibition in micromodels. In order to directly study pore-level fluid distributions as a function of surfactant structure, a state-of-the-art X-ray micro-CT scanner integrated with a miniature core-flooding apparatus was deployed to generate three-dimensional pore-fluid occupancy maps at the pore scale. The core-flooding results revealed that there is an additional set of factors besides pore geometry, rock surface wettability, fluid-fluid interfacial tension, and fluids’ viscosities, densities, and flow rates that directly contributes to the distribution of fluids at the pore scale. We demonstrate that under similar rock and fluid properties, interfacial repulsive and attractive interactions, caused by the adsorption of surface-active chemicals on fluid-fluid interfaces, can significantly alter pore-scale fluid occupancies. Oil cluster analyses along with three-dimensional (3D) visualization of fluid distributions indicate that using the nonionic surfactant with large head instead of the anionic surfactant with small head results in the breaking up of the large and medium oil clusters into smaller and scattered ones. We propose a mechanism relating the stability of oil-brine interface to surfactant structure that is responsible for the break-up and/or coalescence of oil clusters inside the pore space. The suggested mechanism is confirmed by the micro-CT images and associated oil cluster analyses. This phenomenon affects the competition between the frequency of displacement mechanisms causing variations in remaining oil saturations. Using the same microtomography technique, we developed a significantly-improved understanding of pore-level displacement mechanisms during low-salinity surfactant flooding in oil-wet carbonates. In this contribution, in-situ fluid distribution maps, in-situ contact angles, and thicknesses of wetting oil layers were investigated under different brine salinities in the presence and absence of a cationic surfactant at elevated pressure and temperature conditions. The investigation revealed that enhanced oil production during low-salinity surfactant waterflooding is caused by several factors such as a rapid alteration of in-situ contact angles toward neutral-wet state, layer thinning of the oil phase, and an increase in the contribution of small-sized pores to the total oil production. The wettability reversal was more profound when the surfactant injection was succeeding a low-salinity waterflooding. The insights gained in this work using different surfactant molecular structures, rock types, brine salinities, and wettability conditions have direct implications for the design of more effective surfactant-based EOR projects.

Controlled Surfactant Adsorption and Release Within Oil Formations for Enhanced Oil Recovery

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ISBN 13 :
Total Pages : 115 pages
Book Rating : 4.:/5 (961 download)

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Book Synopsis Controlled Surfactant Adsorption and Release Within Oil Formations for Enhanced Oil Recovery by : Hassan Mahdi Alhassawi

Download or read book Controlled Surfactant Adsorption and Release Within Oil Formations for Enhanced Oil Recovery written by Hassan Mahdi Alhassawi and published by . This book was released on 2013 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The adsorption of surfactants onto solid surfaces is a major issue during chemical enhanced oil recovery (EOR) applications. Surfactant adsorption reduces the performance of the chemical injection slug and makes the process uneconomical. In this research, a new surfactant delivery system SDS: B-CD inclusion complex, was evaluated as an approach to decrease surfactant adsorption. The effectiveness of this system on the surfactant adsorptive behavior was determined through static and dynamic adsorption tests. Likewise, the performance of this approach during EOR surfactant flooding was investigated through sandpack displacement tests under simulated oil reservoir conditions. The research outcomes indicate that this new technology is greatly efficient in reducing the adsorption of surfactant onto solid surfaces. Sandpack testing demonstrated that the surfactant is released at the oil saturation zones within the sandpack and higher incremental oil was recovered in comparison with the conventional EOR surfactant flooding. This technology has great potential for EOR applications."--Page ii.

Chemical Enhanced Oil Recovery

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Publisher : Walter de Gruyter GmbH & Co KG
ISBN 13 : 3110640430
Total Pages : 277 pages
Book Rating : 4.1/5 (16 download)

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Book Synopsis Chemical Enhanced Oil Recovery by : Patrizio Raffa

Download or read book Chemical Enhanced Oil Recovery written by Patrizio Raffa and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-07-22 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims at presenting, describing, and summarizing the latest advances in polymer flooding regarding the chemical synthesis of the EOR agents and the numerical simulation of compositional models in porous media, including a description of the possible applications of nanotechnology acting as a booster of traditional chemical EOR processes. A large part of the world economy depends nowadays on non-renewable energy sources, most of them of fossil origin. Though the search for and the development of newer, greener, and more sustainable sources have been going on for the last decades, humanity is still fossil-fuel dependent. Primary and secondary oil recovery techniques merely produce up to a half of the Original Oil In Place. Enhanced Oil Recovery (EOR) processes are aimed at further increasing this value. Among these, chemical EOR techniques (including polymer flooding) present a great potential in low- and medium-viscosity oilfields. • Describes recent advances in chemical enhanced oil recovery. • Contains detailed description of polymer flooding and nanotechnology as promising boosting tools for EOR. • Includes both experimental and theoretical studies. About the Authors Patrizio Raffa is Assistant Professor at the University of Groningen. He focuses on design and synthesis of new polymeric materials optimized for industrial applications such as EOR, coatings and smart materials. He (co)authored about 40 articles in peer reviewed journals. Pablo Druetta works as lecturer at the University of Groningen (RUG) and as engineering consultant. He received his Ph.D. from RUG in 2018 and has been teaching at a graduate level for 15 years. His research focus lies on computational fluid dynamics (CFD).

Surfactants

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Publisher : Cambridge University Press
ISBN 13 : 0521640679
Total Pages : 633 pages
Book Rating : 4.5/5 (216 download)

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Book Synopsis Surfactants by : Laurier Lincoln Schramm

Download or read book Surfactants written by Laurier Lincoln Schramm and published by Cambridge University Press. This book was released on 2000-03-23 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2000 book provides an introduction to the nature, occurrence, physical properties, propagation, and uses of surfactants in the petroleum industry.

Evaluation and Design of Surfactant Formulations for Wettability Alteration

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ISBN 13 :
Total Pages : 484 pages
Book Rating : 4.:/5 (116 download)

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Book Synopsis Evaluation and Design of Surfactant Formulations for Wettability Alteration by : Soumik Das

Download or read book Evaluation and Design of Surfactant Formulations for Wettability Alteration written by Soumik Das and published by . This book was released on 2020 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Only about 35% of oil is recovered from carbonate reservoirs through primary and secondary flooding because of oil wet surfaces and unfavorable capillary pressures. Surfactants, with their dual hydrophobic and hydrophilic nature have been known to improve oil recovery significantly by lowering oil-water interfacial tension and by altering wettability of surfaces. However, the process of selecting an efficient surfactant for wettability alteration is dependent on several factors, including mineral type, porosity, temperature, salinity, nature of adsorbed oil, molecular structure and surfactant adsorption. Core-flood experiments usually used for evaluating surfactants tend to be time-consuming and provide very little information on the actual mechanism of surfactant action. A fast evaluation scheme is hence required to measure surfactant performances corresponding to the above mentioned parameters. The current work focusses on macro and molecular scale analysis of surfactants to understand relevant structure-property relationships and mechanism of wettability alteration. Surfactants are first evaluated and screened through a series of phase behavior, contact angle and oil-film experiments. The experimental observations have been used to correlate parameters like molecular structure, temperature and brine salinity to macroscopic properties like wettability alteration, adsorption and capillary driving force. Oil-film experiments have been used to understand the surfactant-aided wettability alteration. The role of surfactant adsorption in wettability alteration is investigated by static adsorption experiments. Adsorption isotherms are measured for different surfactant hydrophilicities at different temperatures and surfactant cloud point is used to develop a thermodynamic model explaining the universal surfactant behavior. Along with experiments, molecular dynamics simulations are also performed to understand the mechanism of aggregative adsorption of the nonionic surfactants. To address the issue of high temperature, high salinity applications, mixed surfactant formulations of nonionic surfactants and anionic hydrotropes are developed. Detailed investigations are performed to understand the role of hydrotrope structure, concentration and temperature on the mechanism of aqueous stabilization and adsorption and their effect on wettability alteration. Overall, the current work first establishes a macro and molecular-scale understanding of the phenomenon of surfactant-assisted wettability alteration and associated structure-property relationships. While shorter surfactant hydrophilic units and high temperatures are found to exhibit better wettability alteration, in fact it is proximity to surfactant cloud point which is the determining thermodynamic descriptor. Improved wettability alteration is correlated with surfactant adsorption which occurs in an aggregative manner. It also means there is a tradeoff between surfactant adsorption and wettability alteration. Using this knowledge, surfactant formulations are developed to observe and predict enhanced oil recoveries from representative porous media

Surfactant Science and Technology

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Publisher : CRC Press
ISBN 13 : 1439882967
Total Pages : 580 pages
Book Rating : 4.4/5 (398 download)

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Book Synopsis Surfactant Science and Technology by : Laurence S. Romsted

Download or read book Surfactant Science and Technology written by Laurence S. Romsted and published by CRC Press. This book was released on 2014-05-05 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surfactant research explores the forces responsible for surfactant assembly and the critical industrial, medical, and personal applications, including viscosity control, microelectronics, drug stabilization, drug delivery, cosmetics, enhanced oil recovery, and foods. Surfactant Science and Technology: Retrospects and Prospects, "a Festschrift in ho

Design and Selection of Performance Surfactants

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Publisher : CRC Press
ISBN 13 : 9780849397424
Total Pages : 392 pages
Book Rating : 4.3/5 (974 download)

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Book Synopsis Design and Selection of Performance Surfactants by : David R. Karsa

Download or read book Design and Selection of Performance Surfactants written by David R. Karsa and published by CRC Press. This book was released on 1999-11-05 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design and Selection of Performance Surfactants is the resource for clear, informative, in-depth reviews of the most topical areas of surfactant science and technology. This is the second volume in an annual series already recognized as an essential resource for major developments in the field. Topics in this volume include spontaneous polymerization in organized micellar media, the catalytic and kinetic effects in ethoxylation processes, narrow and secondary alcohol ethoxylates, plus the latest advances in flurosurfactants and carbohydrate-derived surfactants. Further readings cover the cutting-edge, microbial and enzymatic production of biosurfactants advances in the computer modeling of surfactants. International contributors detail the latest applications in oil drilling, floor polishes, and food emulsification. Science and industry are constantly refining research and finding new applications for surface chemical technology. Reading Design and Selection of Performance Surfactants is the most efficient and accessible way for chemists, researchers, and manufacturers to stay abreast of the latest developments.

Modeling of Surfactant Transport and Adsorption in Porous Media

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ISBN 13 :
Total Pages : 40 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Modeling of Surfactant Transport and Adsorption in Porous Media by :

Download or read book Modeling of Surfactant Transport and Adsorption in Porous Media written by and published by . This book was released on 1991 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: When surfactant solution is flowing in a reservoir formation, surfactants will be diluted by flow dispersion, retained in dead-end pores, adsorbed on rock surfaces, or precipitated due to ion exchange. The loss of surfactant will be detrimental to the performance of gas foam. Information of surfactant concentration profiles in reservoir formations is essential for gas foaming technique development. The major objective of this research is to investigate with mathematical models the transport and dynamic adsorption of surfactants in porous media. The mathematical models have taken into account the convection, dispersion, capacitance, and adsorption effects on concentrations of surfactants. Numerical methods and computer programs have been developed which can be used to match experimental results and to determine the characterization parameters in the models. The models can be included in foam simulation programs to calculate surfactant concentration profiles in porous media. A flow experimental method was developed to measure the effluent surfactant concentration, which will be used to determine the model parameters. Commercial foaming agent Alipal CD-128 was used in this study. Equilibrium adsorption and surfactant precipitation have been tested. Tracer solutions with a nonadsorbing solute such as dextrose and sucrose were used to determine the dispersion parameters for the experimental sandpack; thus, the adsorption of the surfactant in the test sand can be identified with an adequate model. 49 refs., 21 figs.

Application and Characterization of Surfactants

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Publisher : BoD – Books on Demand
ISBN 13 : 953513325X
Total Pages : 318 pages
Book Rating : 4.5/5 (351 download)

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Book Synopsis Application and Characterization of Surfactants by : Reza Najjar

Download or read book Application and Characterization of Surfactants written by Reza Najjar and published by BoD – Books on Demand. This book was released on 2017-07-05 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surfactants are among the materials that have a significant importance in everyday life of human. The rapid growth in science and technology has opened new horizons in a very wide range, in which the surfactants play a major and vital role. Hence, the increasing number of applications as well as arising environmental issues has made this relatively old topic still a hot research theme. In the first section of this book, some of the applications of surfactants in various fields such as biology and petroleum industry, as well as their environmental effects, are described. In Section 2 some experimental techniques used for characterization of the surfactants have been discussed.

Surfactants: Chemistry, Interfacial Properties, Applications

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Publisher : Elsevier
ISBN 13 : 0080542131
Total Pages : 679 pages
Book Rating : 4.0/5 (85 download)

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Book Synopsis Surfactants: Chemistry, Interfacial Properties, Applications by : D. Möbius

Download or read book Surfactants: Chemistry, Interfacial Properties, Applications written by D. Möbius and published by Elsevier. This book was released on 2001-12-21 with total page 679 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication provides comprehensive material on the chemical and physical attributes of surfactants and new models for the understanding of structure-property relationships. Surfactants Chemistry, Interfacial Properties, Applications provides efficient instruments for the prognostication of principal physicochemical properties and the technologic applicability from the structure of a surfactant through the discussion of interrelations between the chemical structure, physicochemical properties and the efficiency of technologic application. Also included are informative overviews on new experimental techniques and abundant reference material on manufacturers, nomenclature, product properties, and experimental examples. The publication is accompanied by a CD-ROM, which is needed for the application of the thermodynamic and kinetic models to experimental data.

Natural Surfactants

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Publisher : Springer
ISBN 13 : 9783030785475
Total Pages : 45 pages
Book Rating : 4.7/5 (854 download)

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Book Synopsis Natural Surfactants by : Neha Saxena

Download or read book Natural Surfactants written by Neha Saxena and published by Springer. This book was released on 2021-07-16 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the use of natural surfactants in enhanced oil recovery, providing an overview of surfactants, their types, and different physical–chemical properties used to analyse the efficiency of surfactants. Natural surfactants discuss the history of the surfactants, their classification, and the use of surfactants in petroleum industry. Special attention has been paid to natural surfactants and their advantages over synthetic surfactants, including analysing their properties such as emulsification, interfacial tension, and wettability and how these can be used in EOR. This book offers an overview for researchers and graduate students in the fields of petroleum and chemical engineering, as well as oil and gas industry professionals.

Surfactants

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Publisher : BoD – Books on Demand
ISBN 13 : 1837687064
Total Pages : 168 pages
Book Rating : 4.8/5 (376 download)

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Book Synopsis Surfactants by : Olasehinde Owoseni

Download or read book Surfactants written by Olasehinde Owoseni and published by BoD – Books on Demand. This book was released on 2024-01-17 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents detailed fundamentals of surfactant systems and links these fundamentals to emerging perspectives in the field of surfactant science. Key topics include environmentally friendly surfactants, ionic liquid-based surfactants, chemically enhanced oil recovery, synergy of surfactants with clay minerals, and reactions in microheterogeneous surfactant systems. This book is an excellent resource for students, researchers, and industry professionals.

Applications of Surfactants and Nanoparticles in Enhanced Oil Recovery Processes

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

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Book Synopsis Applications of Surfactants and Nanoparticles in Enhanced Oil Recovery Processes by : Christian A. A. Paternina

Download or read book Applications of Surfactants and Nanoparticles in Enhanced Oil Recovery Processes written by Christian A. A. Paternina and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surfactant injection is considered as the EOR (Enhanced Oil Recovery) with the highest potential to recover oil from reservoirs due to its ability to reduce interfacial forces into the porous medium. However, the adsorption of this type of chemical on the surface of rocks is the main problem when a surfactant injection project is applied since the surfactant molecules would rather be placed on rock minerals instead of being the oil,Äìwater interface. Based on this fact, this chapter would be discussed the significance of surfactant injection as an EOR method, the types of surfactants used, the main mechanism and parameters involved in the surfactant adsorption on the rock, and its consequences in oil recovery. Likewise, the addition of nanoparticles to inhibit the adsorption of surfactants is another topic that will be covered as a novel technology to improve the efficiency of the EOR process.

A Study of Surfactant Precipitation in Porous Media with Applications in Surfactant-assisted Enhanced Oil Recovery Processes

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ISBN 13 :
Total Pages : 570 pages
Book Rating : 4.:/5 (464 download)

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Book Synopsis A Study of Surfactant Precipitation in Porous Media with Applications in Surfactant-assisted Enhanced Oil Recovery Processes by : Seyed Alireza Arshad

Download or read book A Study of Surfactant Precipitation in Porous Media with Applications in Surfactant-assisted Enhanced Oil Recovery Processes written by Seyed Alireza Arshad and published by . This book was released on 1991 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (727 download)

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Book Synopsis Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs by :

Download or read book Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes work during the 30 month time period of this project. This was planned originally for 3-years duration, but due to its financial limitations, DOE halted funding after 2 years. The California Institute of Technology continued working on this project for an additional 6 months based on a no-cost extension granted by DOE. The objective of this project is to improve the performance of aqueous phase formulations that are designed to increase oil recovery from fractured, oil-wet carbonate reservoir rock. This process works by increasing the rate and extent of aqueous phase imbibition into the matrix blocks in the reservoir and thereby displacing crude oil normally not recovered in a conventional waterflood operation. The project had three major components: (1) developing methods for the rapid screening of surfactant formulations towards identifying candidates suitable for more detailed evaluation, (2) more fundamental studies to relate the chemical structure of acid components of an oil and surfactants in aqueous solution as relates to their tendency to wet a carbonate surface by oil or water, and (3) a more applied study where aqueous solutions of different commercial surfactants are examined for their ability to recover a West Texas crude oil from a limestone core via an imbibition process. The first item, regarding rapid screening methods for suitable surfactants has been summarized as a Topical Report. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the surface of these chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant oil recovery performance reported in the literature. The second effort is a more fundamental study. It considers the effect of chemical structures of different naphthenic acids (NA) dissolved in decane as model oils that render calcite surfaces oil-wet to a different degree. NAs are common to crude oil and are at least partially responsible for the frequent observation that carbonate reservoirs are oil-wet. Because pure NA compounds are used, trends in wetting behavior can be related to NA molecular structure as measured by solid adsorption, contact angle and our novel, simple flotation test with calcite. Experiments with different surfactants and NA-treated calcite powder provide information about mechanisms responsible for sought after reversal to a water-wet state. Key findings include: (1) more hydrophobic NA's are more prone to induce oil-wetting, and (2) recovery of the model oil from limestone core was better with cationic surfactants, but one nonionic surfactant, Igepal CO-530, also had favorable results. This portion of the project included theoretical calculations to investigate key basic properties of several NAs such as their acidic strength and their relative water/oil solubility, and relate this to their chemical structure. The third category of this project focused on the recovery of a light crude oil from West Texas (McElroy Field) from a carbonate rock (limestone outcrop). For this effort, the first item was to establish a suite of surfactants that would be compatible with the McElroy Field brine. Those were examined further for their ability to recover oil by imbibition. Results demonstrate several types of promising candidates, and that within a given series of nonionic surfactants the oil recovery appears to be related to the HLB of each surfactant. For the McElroy brine and crude oil system, higher HLB (more water soluble) surfactants perform better than in earlier imbibition tests performed with the model oil and a fresh water or low salinity brine. We speculate that this difference mostly is because a more water soluble surfactant is required to be compatible with higher salinity of the McElroy brine (over 3 wt% salt).