无夹层底水油藏直井水锥定量描述

Quantitative description of vertical well water coning in bottom water reservoir with no interlayer

针对无夹层底水油藏,基于剩余油分布预测的目的,进行水锥定量描述非常必要。由于影响水锥范围的因素众多,采用渗流力学方法和数值模拟技术分别定性和定量研究了各因素的影响规律。根据静力学和渗流力学原理,分别考虑远井地带平面径向流和近井地带半球状向心流渗流特征,采用解析方法推导了水锥高度与水锥半径的关系,定性分析了影响水锥范围的主要因素,包括产液量、油水粘度比和避射高度。在此基础上建立典型底水油藏数值概念模型,计算了多种影响因素下的水锥形态,利用多元非线性回归方法得到水锥高度计算公式,通过积分得到水锥体积计算公式。以Z1油藏1口生产井为例,比较并分析了解析方法和定量计算公式的结果,定量计算公式更适用于水锥高度和体积的计算,可以广泛应用于无夹层底水油藏直井水锥范围的计算和预测。

On the basis of static theory and fluid mechanics in porous medium,this paper derives the relationship between the height and radius of water cone in bottom water reservoir with no interlayer using analytic methods,considering radial fluid flow of oil far from the wellbore and the hemispherical centripetal flow of water in immediate vicinity of wellbore respectively.With the analysis of factors affecting water cone,the typical bottom water reservoir numerical conceptual model is established and the water cone shape with a variety of factors is calculated.Using multivariate nonlinear regression method,the relationship between water cone affecting factors and coefficients a1,a2,a3 is determined,the quantitative formula of water coning is set up,and the height and volume of water cone is calculated.The validity of analytical methods and quantitative description formula are confirmed with an example of Z1 reservoir.The results indicate that quantitative description formula can satisfy the needs of oilfield.