天然水驱海相砂岩油藏递减率影响因素研究

Study on Factors Aff ecting Decline Rate of Marine Sandstone Reservoirs in Natural Water Flooding

通过统计南海东部24个天然水驱砂岩油藏的实际生产动态数据,结合地质油藏特征对孔隙度、渗透率、有效厚度、初始含油饱和度、地层原油黏度和井网密度等分析了影响油藏初期自然递减率的主控因素;并运用灰色关联分析法对各影响参数的相对重要性进行了排序:原始含油饱和度>平均孔隙度>平均有效厚度>地层原油黏度>平均渗透率>井网密度;在此基础上,对南海东部天然水驱海相砂岩油藏按照不同驱动类型、不同储层和流体物性进行分类,研究确定了不同类型油藏单井递减率主要分布范围。为同类油藏开发井和调整井开发指标预测提供类比依据。

Through the statistics of the actual production dynamic data of 24 natural water flooding sandstone reservoirs in the eastern South China Sea,and combined with the characteristics of geological reservoirs,the main factors affecting the decline rate of reservoir production were qualitatively analyzed,including porosity,permeability,effective thickness,initial oil saturation,formation crude oil viscosity and well pattern density;And the grey correlation analysis method was used to rank the relative importance of multiple factors;On this basis,natural water flooding sandstone reservoirs in the eastern South China Sea were classified according to different driving force,formation types,and fluid properties,and the main distribution range of single well decline rates in different types of reservoirs was determined through research.The results provide an analogy basis for the prediction of development indexes of development wells and adjustment wells in similar reservoirs.