Technical Research On ASP Flood For Poor Reservoirs In Eastern Fault Of B1 Region

SaZhong oil field has been developed for over forty years and has entered into late production period with high water cut. With commercial polymer flood widely applied in main reservoirs of SaZhong areas, production zones by tertiary recovery process begin to focus on thin and low productivity reservoirs. The recovery by Alkaline-Surfactant-Polymer ( ASP ) flood will be 10% higher than that of polymer flood for Sa and PII poor reservoirs and recoverable reserves will be more than double. Therefore, ASP process has great development potential and bright application future for poor reservoirs.Combining with geological characteristics of poor reservoirs in SaZhong areas, the paper studies well space and the methods for layers compounding development and optimizes developing process for ASP flood in poor servoirs, which has great significance for improving oil recovery and instructing future commercial ASP application in poor reservoirs.The paper systemically studies reservoir properties, oil reserves, recovering situations of present wellpatterns and residual oil potential for poor reservoirs in Eastern Fault of B1 region. Based on test data of polymer flood in poor reservoirs, and with the help of laboratory test and numerical simulation, it is determined that the target zones, suitable for ASP flood, should be channel sands and the reservoirs with effective thickness more than 1m. Considering many factors, such as geological characteristics of poor reservoirs for polymer flood, permeability variations, wellpattern interaction between ASP and polymer flood, surface equipmets for polymer injection, subsequent production, economic benefits and etc, the studies on layer compounding development are conducted in 31 sedimentary cells of SII1-SIII10 reservoirs to fix on production zones. Meanwhile, taking use of periodical conclusions from polymer flood in poor reservoirs, development characteristics of commercial polymer flood and ASP flood, the well space suitable for ASP flood in poor reservoirs is obtained, which analyzes and demonstrates covering extent, improved oil recovery, scaling preventation, application results and economic benefis for different well spaces. And on the basis of the studies on ASP formation system, injection rate and injection process, the initial ASP project has been completed.