三角洲储层渗流参数动态模型研究—以胜坨油田二区下第三系沙二段8^3小层为例

Dynamic model of filterate parameters in delta reservoir

以注水开发 3 6年的胜坨油田二区下第三系沙二段 83 小层的三角洲储层为例 ,应用岩心分析和渗流物理模拟数据 ,研究了渗流参数随注水开发的变化规律和机理 ,建立了渗流参数的润湿性模型、孔隙结构模型和相对渗透率模型。研究结果表明 ,随着注水开发程度的加深和综合含水率的提高 ,该储层岩石的亲水性逐步增强 ;岩石平均比表面积降低 ,孔隙和喉道半径增大 ,孔隙连通性和孔喉分布变好。平均残余油的水相相对渗透率有降低的趋势 ,标准化油水相对渗透率曲线交点的水饱和度向右偏移 ,即交点水饱和度增大。在相同水饱和度下 ,油相渗透率增大 ,水相渗透率下降 。

A delta reservoir of layer 8 3 in the second member of Shahejie Formation of the Paleogene in the second district of Shengtuo oilfield has developed for 36 years with water flooding.The varying laws and mechanism of the filterate parameters in the process of water flood development of this reservoir were studied by using the data of core analysis and filterate physical simulation.Three models for simulating three filterate parameters were established.The simulation results with the wettability model show that the rock wettability and hydrophilicity are enhanced and the specific surface of rock is depressed with the growing of the combined water cut.The simulation of the porous structure model shows that the radii of pores and throat are enlarged,the connectivity of the pores and the factors for controlling the flow property are improved with the increase of current ecovery and water cut of the oilfield.The model for relative permeability of oil and water shows that the average relative permeability of water phase in the remaining oil was decreasing graduslly.The cross point in normalized plots for relative permeability migrated to right,e.g.the water saturation at the cross point increased.Under the same water saturation,the relative permeability of oil phase increased,and the relative permeability of water phase decreased.The change of filterate parameters is due to the dynamical geology process resulted from the fluid in reservoir development.