摘要
将分形几何理论与渗流理论相结合 ,推导不等厚横向非均质油藏不稳定渗流的试井分析数学模型。储集层模型由m (m≥ 2 )个环绕中心的环形区域组成 ,在不同的环形区域内 ,储集层和流体的性质不同 ,其孔隙度和渗透率可以具有不同的分形分布 ;地层厚度也可以不同 ,但在同一区域内看作近似不变。考虑井筒储存和表皮效应影响 ,建立了此类分形复合油藏模型的不稳定渗流有效井径数学模型。针对典型的 3类外边界条件 ,应用Laplace变换求得拉氏空间的解析解 ;制作了 2类两区复合油藏模型的典型压力曲线 ,分析了压力动态特征和参数影响。分形指数对晚期的压力动态有很大影响 :压力曲线开始时合并为一 ,随着时间的增加而发散 ;分形指数值愈大 (表明分形网络越扭曲复杂 ,地层的连通性越差 ) ,直线愈陡 ,反之愈平缓。地层厚度的变化对典型曲线也有一定的影响 ,晚期压力随着厚度增大(第二区逐渐变厚 )而逐步减小。不等厚横向非均质油藏、均质复合油藏及分形油藏均是此模型的特例 ,其建模方法可以推广到双重介质分形复合油藏。
The theories and mathematical model of well testing analysis of fr actal reservoir with non-uniform thickness lateral heterogeneity are discussed. In order to completely describe the situation of real reservoirs, the fractal reservoir with variable thickness is defined as fractal reservoir that consists of many zones with non-uniform thickness, different fluid, different format pro perties and variable fractal parameters. A new effective well radius mathematica l model of this fractal reservoir is suggested in which the wellbore storage and skin effects are considered. The analytical solutions in Laplace-space for th e mathematical model are obtained by Laplace transformation. The dimensionless f lowing wellbore pressure for the modern well test analysis is given by numerical ly inverting method. The well test analysis theories and the pressure behavior o f this reservoir are discussed. The model and solution can be used in the fracta l reservoir with variable formation properties or containing water injection wel ls, gas injection wells, polymer injection wells or finite damaged zone.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2001年第5期49-52,共4页
Petroleum Exploration and Development
基金
油气藏地质及开发工程国家重点实验室开放式基金资助项目 (PLN 0 1 1 5)研究成果
关键词
不等原分形复合油藏
数学模型
压力特征
不稳定渗流
Fractal reservoir, Unstable flow of fluids throu gh porous media, Mathematical model, Analytical solution, Pressure dynamic featu re
