伊陕斜坡西南缘长6_(3)致密砂岩储层流动单元特征

Characteristics of Chang 6_(3) tight sandstone reservoir flow units in the southwest margin of Yishan slope

以鄂尔多斯盆地伊陕斜坡西南缘长63致密砂岩储层为例,在测井特征曲线与岩石学特征的基础上,利用多因素统计分析方法研究致密砂岩储层流动单元特征,并结合动态生产资料,探讨多因素统计分析方法划分低孔、特低渗储层流动单元划分的可靠性。研究表明,通过对孔隙度(φ)、渗透率(K)、单砂体厚度(H)、泥质含量(V_(sh))、流动分层指数(FZI)和孔喉半径(R_(35))6个因素进行主因子分析、聚类分析以及贝叶斯判别,提取出F_(1)(流动因子)、F_(2)(储集因子)、F_(3)(规模因子)、F_(4)(泥质含量因子)4个影响流动单元类型的主控因子,将长6_(3)储层划分为E、G、M、P共4类流动单元,并以贝叶斯判别函数式验证划分结果,E、G、M、P流动单元的正判率分别为100%、98.5%、96.4%、92.1%。

Taking the Chang 6_(3) tight sandstone reservoir in the southwest Yishaan slope in Ordos Basin as an example,the flow unit characteristics of the tight sandstone reservoir are studied by multifactor clustering method based on the characteristic curves of logging and lithological characteristics,and combined with dynamic production data,explore the reliability of multi factor statistical analysis method for dividing flow units in low porosity and ultra-low permeability reservoirs.The study shows that through the main factor analysis,cluster analysis and Bayesian discrimination of six factors,including porosity(φ),permeability(K),single sand body thickness(H),mud content(V_(sh)),flow stratification index(FZI)and pore throat radius(R_(35)),four factors were extracted,including F_(1)(flow factor),F_(2)(reservoir factor),F_(3)(scale factor)and F_(4)(mud content factor).The main control factors affecting the type of flow units were extracted,and the Chang 6_(3) reservoir was divided into four types of flow units,including E,G,M,and P.Based on the Bayesian discrimination function,the positive discrimination rate of E,G,M and P is 100%,98.5%,96.4%and 92.1%,respectively.