Recent Advances in Reservoir Stimulation and EOR Technology in Unconventional Reservoirs

In the past decade, the rapid increase in the production of fossil energy has been made possible by effective reservoir stimulation and enhanced oil recovery (EOR) technologies for unconventional oil and gas reservoirs. As one of the most important reservoir stimulation technologies, hydraulic fracturing  aims to increase the contact area between the target formation and production well. Such stimulation technologies usually involve complex fluid–solid coupling processes, including fracture initiation, fracture propagation, and fracture conductivity, etc. Enhanced oil recovery has been used to solve the problem of oil rate declining sharply after a period of production. In this process, some special chemicals will be injected into the reservoir to increase the recovery effectiveness of the residual oil. EOR processes often involve complex physical–chemical processes, including liquid emulsification, water–rock reactions, etc. Therefore, the progress of reservoir stimulation and EOR technology will contribute to the rapid development of unconventional oil and gas resources. Meanwhile, these technologies are also used in the development of geothermal and coal resources.