高含水稠油油藏超临界水岩心驱替实验研究

Elevated water cut obstructs recovery of heavy oil in later stage of heavy oil reservoir exploitation. This paper simulates such scenarios using one-dimensional sandstone cores filled with saturated oil utilizing hot water flooding. Subsequently, we conducted indoor flooding tests for supercritical water flooding, high-pressure hot water flooding, and superheated steam flooding. Results reveal that supercritical water flooding yields the highest recovery rate (96.27%) and superior in-situ upgrading compared to hot water flooding and superheated steam flooding. The mechanism for enhancing oil recovery via 400^◦C, 25 MPa supercritical water flooding in a high water cut heavy oil reservoir environment lies in the occurrence of thermal fluid breakthrough phenomenon, miscible flooding, and hydrothermal pyrolysis of heavy oil under supercritical water conditions.