Chemical Enhanced Oil Recovery Research Articles

Experimental investigation and machine learning modeling of diethylenetriaminepentaacetic acid agents in sandstone rock wettability alteration: Implications for enhanced oil recovery processes

Chelating agents have garnered increasing attention due to their unique capabilities in addressing challenges associated with chemical enhanced oil recovery (CEOR) materials. This research investigates the transformative potential of diethylenetriaminepentaacetic acid (DTPA) chelating agent in altering sandstone rock wettability. Wettability and zeta potential measurements were used to assess the impact of crucial factors including DTPA concentration, salinity, and potential determining ions (PDIs) on contact angle and rock surface charges. The findings revealed that there is an optimal level for DTPA concentration and salinity that can shift rock wettability from an oil-wet to strongly water-wet state. Moreover, while PDIs in their natural concentrations had no significant impact on DTPA performance, a threefold increase in their concentration was found to adversely affect DTPA efficacy. After conducting rock wettability tests, two advanced machine learning (ML) techniques, namely Random Forest (RF) and Boosted Regression Tree (BRT), were employed to assess rock/oil contact angle based on the aforementioned factors. Data were collected from 240 experimental datasets of contact angles. The findings indicated that both models performed well, but BRT exhibited exceptional performance. Sensitivity analysis, conducted using the Jackknife method, revealed the order of importance for parameters affecting wettability as follows: PDIs > salinity > time > DTPA concentration.

Effective Synergistic Action of Benzimidazolium Nano Gemini Ionic Liquid and Conventional Surfactant for Chemical Enhanced Oil Recovery

Effective Synergistic Action of Benzimidazolium Nano Gemini Ionic Liquid and Conventional Surfactant for Chemical Enhanced Oil Recovery

DISPLACEMENT OF OIL BY MICELLAR SOLUTION WITH NANOPARTICLES FROM POROUS MODEL WITH CORE MATERIAL

Enhanced oil recovery (EOR) techniques play an important role in maintaining oil production worldwide. These methods are given special attention due to the constant decline in the availability of oil resources. One type of EOR is the tertiary method - a chemical method that involves the use of synthetic substances for mining. Liquid flooding in the presence of a surfactant is a common chemical EOR, and microemulsions belong to these systems. The injection of the microemulsion rim reduces the interfacial tension between the crude oil and the formation fluid, which results in the mobilization of a significant portion of the residual oil. Recently, the possibility of simultaneous use of nanoparticles and chemicals to increase the efficiency of the processes of increasing oil recovery has been considered. In this work, nanoparticles participate in the role of microemulsion stabilization, and their joint effect on the displacement capacity of oil from the bulk model of a porous medium is also analyzed. The work is aimed at studying the effect of adding silicon oxide nanoparticles to a microemulsion solution, which is an agent for displacing viscous oil from a bulk porous medium. In the experiment, laboratory studies of oil displacement by various compositions, including surfactants, salt, alcohol and nanoparticles, were carried out on two types of bulk models assembled from glass beads and quartz sand, phase saturations were determined at different points in time, and displacement capacity graphs were built. The oil displacement study was carried out for six liquids: water, mineralized water, nanofluid, aqueous solution with surfactant, also a solution for microemulsion without and with the addition of nanoparticles. It has been found that the effect of adding nanoparticles to the microemulsion composition in the case of bulk models consisting of glass beads leads to a slight increase in the volume of displaced oil. In the case of bulk models consisting of core material, an increase in residual oil saturation is observed, which is associated with adsorption of particles on the surface of core material.

A mini-review on biosurfactants from natural-based resources: Sources, production, and application in oil industries

Increasing energy demand and depletion of producing wells around the globe necessitate oil industries to seek alternative mechanisms to increase oil production. Among various chemical enhanced oil recovery (CEOR) unveiled today, surfactants have become indispensable chemical agents in oil industries because of their wide applications in both onshore and offshore operational activities. Unfortunately, considerable numbers of these surfactants are synthetic causing treatment and disposal of effluents uneconomical to oil industries. This arises due to strong legislation laws enforced by governing bodies to ensure cleaner and safer environments. Consequently, the search for biodegradable surfactants from natural-based resources has revolved around the oil industries aimed at reducing the impacts of synthetic products both environmentally and economically. Plants are widely recognised as natural resources to obtain biosurfactants from their naturally producing saponins. In addition, other chemical compounds derived directly from plant parts are converted to biosurfactants commonly referred to as green biosurfactants. However, researchers have expressed reservations about sustainable biosurfactant production from plants due to limited access to plant resources. The present review discusses the types, properties, sources, synthesis, and applications of biosurfactants in EOR. Furthermore, the paper presents prospects of biosurfactants in EOR and proposes a sustainable production mechanism.

Understanding the Factors Affecting the Adsorption of Surface-Active Agents onto Reservoir Rock in Chemical Enhanced Oil Recovery Applications: A Comprehensive Review

Understanding the Factors Affecting the Adsorption of Surface-Active Agents onto Reservoir Rock in Chemical Enhanced Oil Recovery Applications: A Comprehensive Review

Chemical enhanced oil recovery under Harsh conditions: Investigation of rock permeability and insights from NMR measurements

Injecting surfactant into a hydrocarbon reservoir stands out as a highly effective method for EOR due to its ability to reduce water/oil IFT and alter rock wettability in certain cases. However, the efficiency of this process is compromised in heterogeneous reservoirs, especially carbonates, characterized by significant permeability variations. This study presents findings from three core flooding experiments on heterogeneous carbonate core samples with different permeabilities. The experiments were conducted under representative reservoir conditions of 100 °C, pressures higher than 3000 psi, and seawater salinities and formation water of 57,745 ppm and 213,768 ppm, respectively. In each experiment, seawater was continuously injected followed by continuously injecting a 2500-ppm solution of in-house synthesized Gemini surfactant. Results revealed that the recovery factor was highest in low-permeability rocks and lowest in high-permeability rocks for both seawater and surfactant floods. Surfactant floods yielded additional recoveries of 31%, 23%, and 19% for low, medium, and high-permeability samples, respectively. Nuclear magnetic resonance (NMR) analysis on short analogous core plugs at different flooding stages confirmed these results. Effluent analysis on the produced aqueous phase indicated that dynamic retention was highest (0.467 mg/gm-rock) in the lowest permeability and lowest (0.146 mg/gm-rock) in the highest permeability rock. NMR analysis suggested that the surfactant's recovery performance and dynamic retention were influenced by the larger surface area of low-permeability rocks, facilitating increased contact with the surfactant. Utilizing NMR monitoring in this work enhances EOR insights through integrated studies and coreflooding experiments and establishes a novel framework for complex reservoir conditions.

Effectiveness of inhibitors to prevent asphaltene aggregation: Insights from atomistic and molecular simulations.

The technological landscape for industrial processes handling asphaltene is evolving at a rapid pace due to the increase in the extraction of heavy crude oil. The main underlying challenges in this regard are the flow assurance, the recovery of the spent solvent, and the sophisticated extractor setup required to develop the process to an industrial scale. The number of studies focused on the handling of the asphaltene at the atomic and molecular scales is growing enormously in order to identify new sustainable solvents for the effective extraction of asphaltene from heavy crude oil or oil-bearing sands. This Perspective focuses on the importance of density functional theory and molecular dynamics simulations to explore the broader range of asphaltene inhibitors, e.g., nanoparticles, ionic liquids, and deep eutectic solvents, to prevent asphaltene precipitation. We provide a concise overview of the major accomplishments, analyze the aspects that require attention, and highlight the path-breaking studies having a significant impact on the process of chemical enhanced oil recovery from heavy crude oil reservoirs primarily based on atomistic and molecular simulations.

Impact of cationic surfactant-coated hydrophilic nanoparticles on polymeric solution performance in chemical enhanced oil recovery (CEOR) from a two-dimensional porous medium

This study aims to investigate the mechanisms underlying enhanced oil recovery (EOR) through chemical injection and explore the key parameters influencing these mechanisms in a two-dimensional porous medium. Distilled water, polyacrylamide (PAM), α-Al2O3 nanoparticles, and cetyltrimethylammonium bromide (CTAB) surfactant were employed for this purpose. The effects of interfacial tension (IFT), viscosity, and zeta potential measurement were also examined. The results revealed that the injection of PAM polymer increased the viscosity of the displacing fluid, and enhanced the sweep efficiency. This resulted in a 35 % increase in the oil recovery factor compared to the water injection alone. Furthermore, the introduction of alumina (α-Al2O3) nanoparticles altered the wettability and stabilized the emulsion, leading to a further increase in the oil recovery factor. In the optimal state, the oil recovery factor reached 63.2 %. Moreover, the study of various concentrations of polymer and nanoparticles illustrated that low concentrations of polymer and high concentrations of nanoparticles in the base fluid resulted in higher oil recovery factors. Furthermore, adding CTAB surfactant ended a significant reduction in IFT, with a decrease from 45.03 to 10.33 mN/m. This reduction resulted in the highest oil recovery factor of 69 %. Consequently, the highest oil recovery factor was achieved using PAM polymer at a concentration of 500 ppm, α-Al2O3 nanoparticles at a concentration of 0.1 wt%, and CTAB surfactant at a critical micelle concentration of 1 mM in the base fluid (pure water), with a constant injection flowrate of 0.1 ml/min.

Experimental Investigation of the Suitability of Afzelia africana and Colocasian esculenta as Alternative to Hydroxyethyl cellulose in Enhanced Oil Recovery

Polymer flooding is a chemical enhanced oil recovery where polymer is injected into the reservoir to recover oil that remained in the reservoir after the primary and secondary recovery mechanisms, improves oil recovery by reducing the water mobility ratio and increases the viscosity of the displacing fluids for sweep displacement efficiency of the reservoir. Synthetic polymers are widely used chemical enhanced oil recovery. However, there is a big concern about the high cost of these polymers which can result to high cost of oil production and environmental concerns due to the toxic nature of these polymers. Hence, there is need to source for local polymers that can be environmentally friendly, less expensive and can serve as a mobility control agent in enhanced oil recovery. In this study, experimental analysis was carried out to improve hydrocarbon productivity using local polymers such as Afzelia Africana, Colocasian esculenta and compared with synthetic polymer Hydroxyethyl cellulose. Characterization (FTIR and SEM) of these polymers were carried out to determine the functional groups and the morphology. Rheological behavior of these polymers was investigated. Core-flooding experiment was conducted on the local polymers and the synthetic polymer to examine the potential of these polymers in enhanced oil recovery. The results of the study showed that the samples contained hydroxyl group (OH), carboxyl group (COOH), and amine (NH3) based on the functional groups. The scanning electron microscopy test showed that the samples are mesoporous and crystalline in nature. The rheology test results showed that the samples exhibit shear thinning behavior and a non-Newtonian fluid. The core-flooding experiment showed that Afzelia Africana had oil recovery of 8.4%, 14.4% and 17.6%. More so, Colocasian esculenta had oil recovery of 6.8%, 14.0% and 17.2% while the synthetic polymer had oil recovery of 9.6%, 14.8% and 19.2% for different polymer concentrations of 0.2wt%, 0.3wt% and 0.4wt% respectively. The results from this study showed that the local polymers compared favorably with the synthetic polymer in enhanced oil recovery.

Cooling Damage Characterization and Chemical-Enhanced Oil Recovery in Low-Permeable and High-Waxy Oil Reservoirs

The well productivity of high-waxy reservoirs is highly influenced by temperature changes. A decrease in temperature can cause the precipitation of wax from the crude oil, leading to a decrease in the formation’s drainage capacity and a drop in oil production. In this study, the wax precipitation of crude oil is characterized by rheological properties tests and differential scanning calorimetry (DSC) thermal analysis. The wax damage characteristics of cores and the relative permeability curves at different temperatures were investigated through coreflood experiments. Furthermore, nanoemulsion is selected as a chemical agent for injection fluid. The nuclear magnetic resonance (NMR) scanning technique is used to investigate the effects of oil recovery enhancement at different pores by increasing temperature and adding nanoemulsion. By comparing the changes in T2 spectra and the distribution pattern of residual oil before and after liquid injection, the results have shown that both increasing temperature and adding nanoemulsion have a significant effect on oil recovery. The improvement of micropores is less pronounced compared to macropores. The produced oil mainly comes from the large pores. When the temperature is lower than the crude oil dewaxing point temperature, there is a serious dewaxing plugging phenomenon in the pores. Additionally, by observing the pattern of residual oil distribution at the end of the NMR online drive, it is hereby classified into wax deposition retention type, weak water washing retention type, and immobilized type, each with its own distinct characteristics. Wettability alteration and interfacial tension reduction can help to improve the drainage capacity of high-wax oil reservoirs, which is the main mechanism of nanoemulsion for enhanced oil recovery. These findings are highly valuable for enhancing the comprehension of the impact of highly waxed crude oils on drainage capacity and the ultimate oil recovery rate, particularly in relation to wax precipitation deposition.

The Evolving Landscape of Oil and Gas Chemicals: Convergence of Artificial Intelligence and Chemical-Enhanced Oil Recovery in the Energy Transition Toward Sustainable Energy Systems and Net-Zero Emissions

Chemical-enhanced oil recovery (EOR) is a field of study that can gain significantly from artificial intelligence (AI), addressing uncertainties such as mobility control, interfacial tension reduction, wettability alteration, and emulsifications. The primary objective of this paper is to introduce an integrated framework for AI and chemical EOR for energy harvest operations. Central emphasis is placed on the energy transition, with the aim of expediting the development of cleaner energy harvesting systems and attaining the goal of net-zero emission. To do so, we present how the energy transition is changing the manufacturing of the chemicals for EOR application. For this, the uncertainty associated with materials' design and critical role of the simulators for transferring the laboratory experiences into full-field implementations is discussed. The concept of digitalization and its impact on energy companies are highlighted. The role of digital twin in simulators integration is discussed, emphasizing how increased data access can help design more tolerant chemicals for harsh reservoir environments using real-time data. Also, we discuss how the chemical suppliers, research institutes, startups, and field operators can benefit from self-leaning and robotic laboratories for chemicals manufacturing. Moreover, this paper explores how including AI perspectives can improve our understanding of developing chemical formulations by blending hybrid capabilities. This approach contributes to making energy production more sustainable and aligning with the goal of zero emissions. A workflow is presented to demonstrate how the integration of AI and chemical EOR can be used for both hydrocarbon production and other energy transition operations, such as carbon capture, utilization and storage, hydrogen storage, and geothermal reservoirs. The outcome of this paper stands as a pioneering effort that uniquely addresses these challenges for both academia and the industry and can open many additional doors and identify topics requiring further investigations.

Identifying the mechanisms behind the stability of silica nano- and micro-particles: Effects of particle size, electrolyte concentration and type of ionic species

Silica nanofluids have emerged as promising agents for various applications, such as water treatment, CO2 absorption, and chemical enhanced oil recovery (CEOR). However, their effectiveness can be hindered when transported through porous media, especially in challenging downhole environments. Aggregation of nanofluid suspensions can damage formation integrity, and brine fluids may unintentionally transport fine micro silica particles, warranting an in-depth examination of micro-particle behavior and stability. This study synthesized silica particles of different sizes (10 nm, 50 nm, 1 μm and 2 μm) and meticulously characterized them using advanced techniques of transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal gravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) analysis. Subsequently, 560 combinations (in 5 series of 112 experiments) of micro- and nano-fluids in the presence of four different salts (NaCl, CaCl2, MgSO4 and MgCl2) were prepared. The stability and sedimentation of these combinations were investigated based on zeta potential, particle size, pH, electrical conductivity, and UV-spectrophotometry. The results indicated that sodium ions were effective for maintaining suspension stability at lower salt concentrations, while magnesium ions were preferred for higher salinities. Particle size increase led to instability at low salinities but stability at high salinities, where enthalpy dominated over entropy. Derjaguin-Landau-Verwey-Overbeek (DLVO) modeling accurately predicted particle interactions and aggregation tendencies. This investigation enhanced the understanding of the mechanisms governing silica particle stability through diverse analytical methods, addressing their limitations. The analysis of UV data over time revealed insights into sedimentation and aggregation kinetics. In summary, this study comprehensively explored the behavior and stability of silica particles in nano- and micro-fluids, shedding light on their performance in applications ranging from enhanced oil recovery to water treatment.

Lessons Learned in Interfacial Tension Prediction Using a Mixture of Sulfonate- and Ethoxylate-based Surfactants in a Waxy Oil-brine System

The chemical-enhanced oil recovery (CEOR) method is applied to change reservoir rock or fluid characteristics by injecting alkaline, surfactant, and polymer or a combination of two or three of the compounds. Surfactant flooding improves oil recovery by reducing the interfacial tension between oil and water. Selecting reservoir surfactants, especially microemulsions, requires careful screening. This study predicted waxy oil system interfacial tension using surfactant mixtures at below- and above-optimum salinity. To predict the interfacial tension, microemulsion types, HLB, ideal salinity, and HLD were used. The study predicted oil-surfactant-water interfacial tension using SAE, FEO, and their mixtures. We improved the Huh equation by adding a fitting parameter, β, to accommodate the transition from type III to type II microemulsions as salinity increases. With increasing salinity, anionic surfactant’s hydrophilic-hydrophobic interactions change, affecting the values and surfactant layer thickness. This study improved hydrophilic-lipophilic deviation (HLDN) by establishing a fixed interval for nonionic surfactants. Van der Waals attraction, values and interface surfactant layer thickness are connected, reflecting the fact that lower values reduce interfacial tension better. This study also found that surfactant packing at the oil-water interface increases the order of the oil-solution ratio and the microemulsion values with polarity.

Experimental investigation of new derived anionic natural surfactant from peanut oil: Application for enhanced oil recovery

Nowadays, there is a growing inclination towards the environmentally friendly and economically viable materials in the field of chemical enhanced oil recovery including the surfactant flooding. This study investigates the performance of a newly developed anionic surfactant derived from peanut oil in enhanced oil recovery (EOR) applications. The validity of the formulated surfactant using the esterification and sulfonation methods was verified through FTIR, 1H NMR, and TGA analytical techniques. According to the outputs of conductivity and surface tension from developed surfactant solutions at 500 and 4000 ppm, the concentration of 2000 ppm was identified as the critical micelle concentration (CMC). Several experimental tests were applied on the surfactant solutions and more specifically at CMC range, such as IFT measurement, wettability estimation, foamability, oil displacement and emulsification. The surfactant solution at CMC (optimal surfactant solution) reduced the IFT from an initial value of 15.5 to 6.8 × 10−2 mN/m at the optimum concentration of formation water (15,000 ppm). Wettability alteration was examined on sandstone and carbonate rock samples, and the optimal surfactant solution successfully altered both rock surfaces from strongly oil-wet to water-wet, resulting in a decrease in contact angle from 144° to 58° on carbonate rock and from 138° to 44° on sandstone rock. In addition, the emulsion test results revealed a significant ability of the peanut surfactant to create emulsions. Examination of microscopic images demonstrated that the emulsion remained stable for approximately 90 days with a high compatibility under high saline conditions. Hence, the developed natural surfactant enabled to displace extra 19.3 % and 15.64 % original oil in place (OOIP) from the sandstone and carbonate core plugs, respectively, with shifting the relative permeability curves towards the lift side.

Effects of Dodecyltrimethylammonium chloride (DAC) micelle’s shape transition on chemical enhanced oil recovery; experimental & mathematical modeling study

Surfactants are widely used for enhanced oil recovery (EOR) purposes by reducing interfacial tension (IFT) of oil–water phases and wettability alteration. Some surfactants with viscoelastic properties can be used as mobility control agents due to enhanced viscosity resulting from the spherical-to-cylindrical shape transition of micelles. Dodecyltrimethylammonium chloride (DAC) shows viscoelastic behavior coupled with dominantly cylindrical shape of the micelle in ambient conditions. Nevertheless, using DAC as an IFT reduction and mobility control agent needs to be industrialized for actual operating conditions. In this study, DAC, as a cationic surfactant, was experimentally studied in reservoir conditions considering dominantly cylindrical micelles for the first time. Results showed that the viscosity of DAC solution is a strong function of DAC concentration, especially at high temperature and high salinity conditions, while it does not depend on pressure significantly. Transmission electron microscope (TEM) images were taken for a better understanding of DAC micellar structures. Analysis of the TEM results indicated the shape transition of the micelles from small spherical to large cylindrical at higher concentrations of DAC. IFT of DAC microemulsion was studied for wide ranges of temperature and DAC concentration, ruling out any significant effect of the temperature on the IFT trend line. A general mathematical model for predicting the viscosity of surfactant solution was developed and evaluated for real reservoir conditions by including all effective terms. Results showed a very good agreement with experimental data of DAC and Cetyltrimethyl ammonium bromide (CTAB, as per previous studies), justifying the applicability of the developed model for predicting the viscosity wherever experimental data is unavailable. Core flood tests were performed with saltwater (SW) and DAC solutions with spherical (SS) and cylindrical (SC) micelles as injecting phases for evaluation of IFT reduction and mobility control effects. Results showed an additional recovery factor of 13 % for SS and 23 % for SC in comparison with SW injection.

Application of a new anionic surfactant based on sesame oil by Alkali-Surfactant (AS) injection in chemical enhanced oil Recovery: Characterization, mechanisms and performance

This study is centered on creating an anionic surfactant using edible sesame oil for enhanced oil recovery (EOR) objects. The surfactant was synthesized under esterification and sulfonation processes. Characterization analyses were performed to describe the surfactant and evaluate its temperature stability. Related experiments were conducted to investigate phase behavior, surface activity, and EOR implications of the surfactant. A chemical flooding experiment was carried out. This involved injecting the surfactant along with the appropriate levels of salinity and alkalinity, into a carbonate plug. Additionally, the ability of the surfactant to generate and maintain foam and emulsion was examined. The surface tension values were reduced from 64 to 33.07 mN/m, and the interfacial tension (IFT) values dropped from 21 to 0.81 mN/m. Through these experiments, the critical micelle concentration (CMC) of the surfactant was determined to be 800 ppm. Upon reaching the CMC, the IFT further decreased to 0.38 and 0.14 mN/m at optimal salinity and alkalinity levels respectively. The previously hydrophobic carbonate surface underwent significant improvement in wettability, transitioning to hydrophilic behavior. This shift was evident as the contact angle decreased from 130.2° to 58.8° within a brief 60-minute equilibration period, representing a suitable wettability state for EOR. The surfactant exhibited an emulsion and foam stability period lasting 35 days. Additionally, its ability to function effectively in the presence of sodium chloride (NaCl) ions was verified with compatibility demonstrated at salinity levels below 100000 ppm. Ultimately, the flooding outcomes displayed a notable 16.18 % enhancement in oil recovery when employing the optimum fluid.

Investigation of the interfacial phenomena in the presence of nonionic surfactants and a silica nanoparticle at the n-decane-water interface: Insights from molecular dynamics simulation

In chemical enhanced oil recovery (EOR), the nanoparticles can be employed as conveyors to transfer the surfactants and impede the reduction of surfactant concentration. Here, a set of molecular dynamic simulations were carried out to examine the ability of hydrophobic silica nanoparticle (NP) to deliver the nonionic surfactant (Triethylene glycol monododecyl ether; C12E3) into the n-decane-water interface. Another set of simulations in which only surfactant molecules are initially located at the interface was performed in order to better characterize the influence of NP on the surfactant adsorption film.The NP exhibited high efficiency in delivering surfactant molecules to the n-decane-water interface. In addition, for the C12E3-NP and n-decane-NP, the Coulombic interactions are weaker than the van der Waals interactions confirming the nonpolar property of the silica nanoparticle. The density profiles indicate that as the concentration of surfactants increases at the interface, NP separates more from the surfactant layer. The interfacial tension (IFT) of n-decane-water systems containing only surfactants decreases as the surface coverage of the surfactants increases. Moreover, it was also proved that the intrinsic width of the interface increases with an increment in the surface coverage of surfactants. The surfactant molecules exhibit a great tendency to contribute as acceptors to the formation of hydrogen bonds with water molecules. With an increment in the surface coverage of surfactant molecules, the 2D radial distribution functions between the centers of mass (COMs) of surfactant tails show oscillations. Appeared oscillations represent the correlation between the surfactant tails. Presence of NP causes the oscillations start at lower surfactant coverage than without NP. The surfactant tails choose a random distribution at the low surface coverage of surfactants. In addition, they tend to be oriented partially perpendicular to the interface with an increase in surfactant surface coverage. Besides, NP causes the surfactant tails to orient more perpendicular to the interface than surfactants alone.

Wettability Alteration Mechanisms in Enhanced Oil Recovery with Surfactants and Nanofluids: A Review with Microfluidic Applications

Modifying reservoir surface wetting properties is an appealing topic to the upstream oil and gas industry for enhancing hydrocarbon recovery as the shifting of reservoir rock surface wetting from oil-wet to water-wet has enhanced the oil recovery by as much as 70–80%. In the last few decades, research has been conducted on core flooding experiments to reveal wettability alteration mechanisms associated with macroscopic fluid flow in reservoirs. In recent years, the microscopic wetting state and fluid distribution behavior have been studied using micromodel experimental techniques to promote the fundamental mechanisms of wettability alteration. To provide the concurrent knowledge and technology development, this comprehensive review focuses on micromodel investigations for wettability alteration in chemical-enhanced oil recovery using surfactants and/or nanofluids that reveal microscopic behaviors on the wetting state, fluid distribution, and their associated mechanisms. This comprehensive review focuses on micromodel investigations for wettability alteration in chemical-enhanced oil recovery using surfactants and/or nanofluids that reveal microscopic behaviors on the wetting state, fluid distribution, and their associated mechanisms. Wettability characteristics and measurement techniques are thoroughly assessed to understand the critical role of wettability for enhanced oil recovery. With the microfluidic-based studies, the effect of relative permeability along with the pore network and wetting order on oil recovery have been discussed. Later on, the new development in phase diagram related to viscus fingering and capillary fingering regime have been reviewed via various micromodels. Then, the wettability alteration mechanisms and governing parameters by surfactant and nanoparticles are summarized. Additionally, recent micromodel experiments on surfactants and nanofluid-assisted enhanced oil recovery are reviewed and listed, along with their fabrication methods.

A multi-mechanistic approach to the oil recovery study of a family of amphiphilic polysaccharides

Chemical enhanced oil recovery (cEOR) remains one of the most potent tertiary recovery techniques. However, it is expensive and rarely environmentally friendly. Bio-based amphiphilic polymers have been suggested as an alternative to eradicating the challenges of conventional cEOR because of cost-effectiveness, and sustainability. Unfortunately, few in-depth studies exist in the literature to investigate the prospects of these materials. A new family of amphiphilic polysaccharides was synthesized by hydrophobic modification of cellulose sulphate, and the EOR functionalities were tested. The novel biopolymers exhibited the ability to alter rock wetting properties. In terms of recovery, one of the variants of the synthesized bio amphiphilic polymer (D-I) was able to reduce residual oil saturation to 12% at harsh conditions of 60,000 ppm salinity at 75 °C. Micromodel visual analysis revealed that the performance of the novel materials was due to the combination of mobility control, IFT lowering and emulsification, wettability alteration, and viscoelasticity. With a performance commensurate to that of a commercial hydrophobically modified polymer, it can be said that the novel amphiphilic polysaccharides can stand as a viable cEOR agent for oilfield applications.

Nanotechnology Impact on Chemical-Enhanced Oil Recovery: A Review and Bibliometric Analysis of Recent Developments.

Oil and gas are only two industries that could change because of nanotechnology, a rapidly growing field. The chemical-enhanced oil recovery (CEOR) method uses chemicals to accelerate oil flow from reservoirs. New and enhanced CEOR compounds that are more efficient and eco-friendly can be created using nanotechnology. One of the main research areas is creating novel nanomaterials that can transfer EOR chemicals to the reservoir more effectively. It was creating nanoparticles that can be used to change the viscosity and surface tension of reservoir fluids and constructing nanoparticles that can be utilized to improve the efficiency of the EOR compounds that are already in use. The assessment also identifies some difficulties that must be overcome before nanotechnology-based EOR can become widely used in industry. These difficulties include the requirement for creating mass-producible, cost-effective nanomaterials. There is a need to create strategies for supplying nanomaterials to the reservoir without endangering the formation of the reservoir. The requirement is to evaluate the environmental effects of CEOR compounds based on nanotechnology. The advantages of nanotechnology-based EOR are substantial despite the difficulties. Nanotechnology could make oil production more effective, profitable, and less environmentally harmful. An extensive overview of the most current advancements in nanotechnology-based EOR is provided in this paper. It is a useful resource for researchers and business people interested in this area. This review's analysis of current advancements in nanotechnology-based EOR shows that this area is attracting more and more attention. There have been a lot more publications on this subject in recent years, and a lot of research is being done on many facets of nanotechnology-based EOR. The scientometric investigation discovered serious inadequacies in earlier studies on adopting EOR and its potential benefits for a sustainable future. Research partnerships, joint ventures, and cutting-edge technology that consider assessing current changes and advances in oil output can all benefit from the results of our scientometric analysis.