The Equilibrium Displacement Of Injection-production System Optimization Study Of Low Permeability Reservoirs

Affected by different characteristic of oil bearing strata,low permeability reservoirs have problems of high development effectiveness disparities,prominent contradiction between layers,and it also affected by factors such as well pattern conditions and well proration,that's difficult to accomplish the equilibrium displacement of reservoir.For heterogeneous reservoir,it must achieve a high equilibrium displacement degree,to realize the largest crude oil extraction efficiency.This paper establishes a mathematical model of Multi-layer heterogeneous reservoir,the influence of factors such as vertical heterogeneity and formation thickness towards displacement result are studied;plane heterogeneity of reservoir water flooding model was deduced,and analyze the effects of reservoir plane heterogeneity,reconstruct and readjust a balanced water injection-production system;based on the principle of equilibrium displacement and the target of the largest fluid volume,the low permeability reservoirs injection-production parameters optimization mathematical model is built,and optimizing and designing the injection-production parameter of the target block,establishing reasonable injection-production parameter calculation chart,then based on the target block geological characteristics,using reservoir numerical simulation method,optimizing injection-production parameters,radial drilling parameters and hydraulic fracturing parameters;Finally combined with radial drilling and hydraulic fracturing measures,optimizing and studing the injection-production system of the target block.The research result shows that: vertical and plane heterogeneity of reservoir are the two main factors affecting reservoir equilibrium displacement,when the reservoir heterogeneity exceeds a certain limit,it is cannot reach equilibrium displacement only through adjusting injection-production parameters,it is must adopting hydraulic fracturing and radial drilling measures to solved the problem of reservoir equilibrium displacement at the same time.As to the target blocks,when the reservoir permeability range is greater than 14~15 and the vertical permeability range is greater than 13 ~ 15,it is cannot reach equilibrium displacement only by adjusting injection-production parameters,it is must using hydraulic fracturing and radial drilling measures.The verrtical longitudinal displacement can be adjusted through the radial drilling measures,the plane displacement can be adjusted through the hydraulic fracturing measures.In this paper,the research for multilayer heterogeneity reservoir has a certain guiding significance to the development of reservoir.