Review on Oil Displacement Technologies of Enhanced Oil Recovery: State-of-the-Art and Outlook

Abstract

Despite rapid advances in renewable energy extraction and utilization, global oil demand continues to rise. Oil displacement technologies are widely studied and applied because they can extract more oil in depleted reservoirs or recover unconventional ones. This study introduces research methods and mechanisms of four oil displacement technologies, i.e., water flooding, chemical flooding, gas flooding, and steam flooding. Although oil displacement technologies are helping to meet the growing demand for oil and energy, there are still some challenges for industrial applications. Some agents adopted in the oil displacement have shortcomings in the corrosion of mining equipment and damage to the reservoir structure. Therefore, solutions to the problem are crucial and are investigated widely in the literature using experiments and simulations. For experimental research, a diffusion framework for studying mass transfer in the oil displacement process and an experimental system for simulating oil displacement in offshore reservoirs should be built, which will facilitate the widespread industrial application of oil displacement technology. Therefore, it is necessary to improve the accuracy and expand the application range of the experimental system. As for numerical simulation, reaction kinetics research is essential for selecting displacement agent materials and preventing harmful gas leakage for industrial applications. However, the dynamics of foam flooding and CO2 flooding are not thoroughly studied. Moreover, it is an acceptable research topic that reducing the uncertainty of discrete regions is an effective method to improve the accuracy of numerical simulation results. For the broader application of oil displacement technology to industry, several mechanisms regarding the research field could be studied more thoroughly and comprehensively in the future, i.e., (1) the influence mechanisms of some impurities and complex reservoir physical properties, (2) the method of combining various oil displacement technologies, (3) the T-H-M-C multifield coupling oil displacement mechanism at micro/nanoscale, (4) the cement failure mechanism caused by CO2 and H2S, and (5) the tube brittle fracture mechanism caused by stress corrosion. For the sustainable development and efficient utilization of oil displacement, this review summarizes the extensive information about four oil displacement technologies, thus encouraging and providing research topics for further development and applications.

Study on Steam and Microemulsion Alternate Injection for Enhanced Productivity in Heavy Oil Fields

“…By adsorbing on the interface between the two immiscible liquids, the micelle decreases the interfacial tension between the two liquids (as seen in Table ), contributing to a possible mixture between oil and water, facilitating the oil’s exit from inside the pore, making oil free to migrate in the reservoir and thus be produced. Another contribution of the microemulsion, and the most important one in this process, is the adsorption of the micelle at the oil–rock interface, which reduces the interfacial tension while the rock surface becomes water-wet (Table ), a condition that makes oil move out of the pore and no longer adsorb to the rock. , It is also worth noting that the injection of the microemulsion after the steam injection can be more effective since the oil may have its viscosity reduced by the thermal effect …”

“…Another contribution of the microemulsion, and the most important one in this process, is the adsorption of the micelle at the oil−rock interface, which reduces the interfacial tension while the rock surface becomes water-wet (Table 5), a condition that makes oil move out of the pore and no longer adsorb to the rock. 38,39 It is also worth noting that the injection of the microemulsion after the steam injection can be more effective since the oil may have its viscosity reduced by the thermal effect. 40 Considering the results of the tests for the hybrid recovery method, the highest oil recovery value was obtained using steam + MS3 (51.23%�Figure 8), with the MS3 microemulsion being the one that presents in its formulation a greater amount of active matter (25% C/T�Table 2).…”

Review on CeO2-Based Photocatalysts for Photocatalytic Reduction of CO2: Progresses and Perspectives

“…The 2D hexagonal structure of the catalyst allowed for the achievement of increased specific surface area and graded porosity in the photoreduction of CO 2 to CO and CH 4 under visible light irradiation, with yields of 11 and 68 mmol•g cat −1 after 6 h, respectively. Wang et al 69 used the ordered mesoporous SBA-15 as a template to synthesize CeO 2 catalysts with different amounts of Fe doping, and then, they tested their catalytic performance for the photocatalytic reduction of CO 2 with H 2 O in the presence of simulated solar radiation. In addition to a larger specific surface area and graded porosity, it was discovered that Fe-doped CeO 2 composite catalysts feature a well-ordered 2D hexagonal mesoscopic structure.…”

Effect of Self-Aggregation Behavior of Geminized Cationic Amphiphilic Macromolecules on the Removal Mechanism of Asphaltenes

“…Heavy oil deposition on rock surfaces poses a big challenge for enhancing oil recovery (EOR). , Among heavy ends in crude oil, asphaltenes consist of polyaromatic structures and aliphatic side chains, which are defined as very polar compounds. These polar functional groups in asphaltenes are generally responsible for their aggregation/adhesion on surfaces and can lead to pipe clogging or hinder oil recovery. , Over the past few decades, thermal, water, and chemical methods have been widely developed to improve heavy oil recovery, of which polymer flooding techniques are regarded as the most promising approaches for many oil reservoirs. , For example, hydrolyzed polyacrylamide (HPAM) can usually enhance the mobility ratio of crude oil when it is dispersed into flooding solvent, but such conventional polymers have a significant tendency to degrade. , …”