制作含水率与采出程度关系理论曲线常犯错误及解决办法

Common problems and solutions in plotting theoretical curves of water-cut vs.recovery percent of reserves

制作含水率与采出程度关系理论曲线常采用相渗曲线法和流管法两种方法。在采用相渗曲线法制作理论曲线时,采用统计回归分析相对渗透率与含水率的关系,导致在低含水饱和度时期含水率偏高,在高含水饱和度时期含水率偏低的问题,解决的方法是直接使用实验数据点计算。将体积波及系数取常数往往会得出“中低含水期开发效果较差,高含水期开发效果较好”的通用结论,解决的方法是分析体积波及系数与井网系统、流度比、渗透率变异系数的关系,建立统计关系式。

Relative permeability curve method and stream-tube method are commonly used to plot theoretical curves of water-cut vs.recovery percent of reserves.When the former method is used to plot the theoretical curves,the rela- tionship between relative permeability and water cut is often analyzed through statistical and regression analyses,re- sulting in water cut tends to be high in low water saturation stage,and tends to be low in high water saturation stage. This problem can be solved by directly using experimental data to calculate.If a constant value is assigned to volu- metric sweep efficiency,a universal conclusion is often obtained,i.e.development effects are relatively poor in medium-low water cut stage,and are relatively good in high water cut stage.This problem can be solved by establish- ing statistical relational expression through analyzing the relationship between volumetric sweep efficiency,mobility ra- tio in a pattern system and permeability variation coefficient.