变原油黏度油水两相流驱替特征研究

为了研究水驱油田开发过程中的原油黏度升高对水驱油的驱替特征影响 ,在经典的非活塞式驱替理论的基础上 ,考虑驱替过程中原油黏度的升高 ,进一步完善了非活塞式驱油理论 ,建立了一个一维油水两相渗流模型 ,并采用解析法和有限差分法两种方法对饱和度方程进行了求解 .用数学模拟的结果研究了原油黏度随含水率上升的 5种变化规律对无水采油期、注入孔隙体积与采收率关系等驱替特征的影响 .结合太平油田沾 1 4块太 1 0 - 1 2井原油黏度随含水上升的变化规律 ,对比了考虑原油黏度变化和不考虑原油黏度变化两种情况下采出程度的差异 .研究结果表明 :开发过程中原油黏度的升高明显地缩短无水采油期 ,加剧含水上升速度 ;未考虑黏度升高的经典驱替理论方法预测的采收率偏高

Dynamic Displacement Characteristics of Water Driving Oil Under the Variation of Crude Oil Viscosity

In order to study the effects of the increase of crude oil viscosity with water cut in process of water drive on dynamic displacement characteristics, classical non piston displacement theory is improved by considering the increase of crude oil viscosity, and a one dimensional mathematical model for oil/water two phase percolation flow through porous media is established. The water saturation equation is solved separately by analytical method and finite element method. The effects of five variation laws of crude oil viscosity with water cut on water free oil production period, and the correlation of injection porous volume to recovery factor are studied by means of simulated results. The recovery percents of reserves under two cases of varying crude oil viscosity and constant crude oil viscosity are compared by means of the correlation of Tai 10 12 well in Zhan 14 block of Taiping oilfield. The results of the research in this paper show that the increase of crude oil viscosity with water cut reduces water free oil production period and accelerate the increasing of water cut; the recovery factor predicted by classical non piston displacement method is higher than that by the improved method in this paper.