Study On Remaining Oil Distribution And Pressure Flooding Numerical Simulation Of Fault Block Reservoir

In the middle and late stage of development of fault block reservoir,the distribution of remaining oil is complex and it is difficult to tap potential and increase efficiency.As a way to improve water flooding development,pressure flooding can effectively supplement formation energy,improve the corresponding relationship of wells between injection and production,and improve the utilization rate of water injection.The existing theories and research show that this technology can meet the needs of tapping potential and adjustment of fault block reservoir in high water cut stage to a certain extent.However,due to the complexity of fault block reservoir development and pressure flooding technology is still in the research and development stage,especially the main controlling factors of different types of reservoirs are not clear,and the injection production technology policy is not clear,which greatly restricts the popularization and application of pressure flooding technology.For fault block reservoirs with different reservoir types,typical reservoir models are established,the distribution law of remaining oil in high water cut period is studied,and the applicability of pressure flooding technology for fractured,porous and composite reservoirs is evaluated and studied on the basis of combing and summarizing the distribution characteristics of remaining oil.Main understandings and conclusions of the study:(1)Using the reservoir numerical simulation method,the main controlling factors affecting the pressure flooding effect of fractured reservoir are selected:periodic injection volume,matrix permeability,underground crude oil viscosity and fracture permeability.The main action mechanism is to supplement formation energy,improve water flooding sweep volume,and promote fluid exchange between fracture and matrix;The pressure flooding technology policy of typical cases is recommended:the liquid production rate is10m~3/d～20m~3/d,the injection speed is 400m~3/d～700m~3/d,and the periodic injection volume is appropriately increased.(2)Using reservoir numerical simulation method,the main controlling factors affecting pressure flooding effect of porous reservoir are selected:periodic injection rate,permeability and heterogeneity.The main action mechanism is to supplement formation energy,improve the production degree of low-permeability layer and flow field alternation.The pressure flooding technology policy of typical cases is recommended:the liquid production rate is 10m~3/d～20m~3/d,the injection rate is 400m~3/d～700m~3/d,and the periodic injection volume is appropriately increased.(3)Using the reservoir numerical simulation method,the main controlling factors affecting the pressure flooding effect of plane composite reservoir are selected:underground crude oil viscosity,liquid production rate and composite characteristics.The main action mechanism is alternating flow field,increasing energy and increasing production.The pressure flooding technology policy of typical cases is recommended:the liquid production rate is 4m~3/d～8m~3/d,the injection rate is 50m~3/d～100m~3/d,and the periodic injection volume is appropriately increased.