裂缝性底水油藏基质储量动用程度研究

On Matrix Reserves Producing in Fractured Reservoirs with Bottom Water

裂缝性底水油藏的储层类型为双重孔隙介质,分为裂缝和基岩两部分,目前国内外一般都是对整个油藏的采出程度进行研究,对裂缝性油藏裂缝系统和基质系统采出程度分别研究的极少,这类油藏由于裂缝发育、底水能量强,容易造成底水沿裂缝的快速锥进,油井含水上升快,产量递减幅度大,因此准确认识基质系统储量的动用程度对于该类型油藏的开发具有一定指导意义。利用物质平衡方法分别建立了基质、裂缝系统的物质平衡方程,结合Leverett函数,通过实例分别计算出了某裂缝性底水油藏基质系统和裂缝系统储量的动用程度,并预测了最终基质系统储量的采出程度;将该结果与同类裂缝性油藏开发效果对比表明,该裂缝性底水油藏裂缝系统和基质系统的动用程度都较好。

The reservoir type of fractured bottom water reservoirs was dual pore media.It was divided into fracture and matrix systems,it was common to study oil recovery percent of the whole reservoir at home and abroad,it was rarely to study oil recovery percents of the matrix and fracture systems respectively.Because of the existence of fracture and powerful energy of the bottom water,bottom water coning fast along the fracture,water-cut increased quickly and oil production rate declined rapidly.It was of great significance for accurately understanding the reserves producing extent from matrix system for the reservoir development at the stage.By using material balance method,a material balance equation was established for the matrix and fracture systems.Combined with Leverett function,and the ultimate reserves producing extent of matrix of a fractured bottom water reservoir was calculated through case study and ultimate recovery percent of the matrix system was predicted.The result is compared with oil recovery of the same type of reservoirs,it is indicated that the recovery percents of the matrix and fracture systems in fractured bottom water reservoir are higher than others.