Investigating Enhanced Oil Recovery Techniques in Ultratight Reservoirs Through Coreflooding Experiments

Abstract

This study explores the efficacy of various enhanced oil recovery (EOR) techniques, including water alternating gas (WAG), gas alternating water (GAW), alkaline surfactant polymer (ASP), and chemical WAG (CWAG) injections. Through coreflooding tests and analysis, we assess their effectiveness in mobilizing and displacing trapped oil in reservoirs. Our findings reveal significant novelty in the chemical methods developed, particularly in CWAG injection strategies, which achieved remarkable oil recovery factors. Specifically, WAG injection demonstrated superior performance, with a maximum oil recovery factor of 64.5%, attributable to water’s higher displacement efficiency. ASP injections also emerged as a promising method, achieving a maximum oil recovery factor of 69.5%, offering comparable recovery to traditional techniques while enhancing sweep efficiency. Furthermore, advanced CWAG injection strategies showcased significant improvements, with CWAG1, CWAG2, CWAG3, and CWAG4 achieving oil recovery factors of 73.5%, 76%, 82%, and 93%, respectively. These insights highlight the critical role of chemical formulation, injection sequence, and optimization techniques in maximizing oil recovery, thereby, contributing to sustainable resource management and economic viability.