Experimental Study on Enhanced Oil Recovery by Microbial Chemical Flooding in High Pour Point Oil Reservoir

High pouching oil is characterized by high freezing point, high wax content and high wax extraction temperature. During the development process, the oil reservoir is prone to wax precipitation, forming cold damage, resulting in low water drive recovery. Using microbial high-throughput sequencing analysis, chemical flooding experimental evaluation methods, core physical simulation and CT scanning, the technology of microbial+chemical composite flooding combination to improve oil recovery of high pour point oil is proposed, and the microbial chemical composite flooding formula is developed, This system has the dual advantages of chemical flooding, which can greatly improve the oil displacement efficiency and reduce the wax component of crude oil by microorganisms. Finally, the slug combination of microbial and chemical flooding formula is optimized through physical model experiment. The experimental results show that the oil displacement efficiency of microbial+chemical composite flooding is 35.19% higher than that of water flooding, 7.27% higher than that of single chemical composite flooding, and 1.16 t/t higher than that of polymer flooding. This study provides an effective replacement technology for mode conversion and enhanced oil recovery in the later stage of development of high pour point oil reservoirs.