鄂尔多斯盆地靖安油田杨66井区延91储层非均质性

Heterogeneity of Yan 91 Reservoir in Yang 66 Wellblock of Jing'an Oilfield,Ordos Basin

靖安油田杨66区延91油层亚组石油稳产困难,开发难度大,小层之间储层特征差异比较明显,这在一定程度上与储层非均质性密切相关。通过岩心观察及测试、测井资料统计及分析,从宏观和微观角度对延91油层亚组的延911和延912这2个小层的非均质性特征进行对比研究。结果表明:延912储层变异系数、级差、夹层频率及分层系数均较高,且主要发育沙纹交错层理,其层内和层间非均质性均较强;延911小层砂体宽度及储层物性变化较大,砂体连片性较差,其平面非均质性较强;延911小层砂岩颗粒大小、胶结物含量、孔喉半径范围变化均较大,填隙物类型较多,物性相对较差,其微观非均质性也较强。

It is difficult to stabilize the oil production of Yan91 oil layer in Yang66 area of Jing'an oilfield,and it is difficult to develop it.The difference between sub-layers in reservoir characteristics is obvious,which is closely related to the reservoir heterogeneity to a certain extent.According to core observation and the statistics and analysis of testing and logging data,the heterogeneity characteristics of sublayers Yan911 and Yan912 in Yan91 oil layer are studied from macro and micro perspectives.The results show that:the variation coefficient,permeability difference,interlayer frequency and stratification coefficient of Yan912 sublayer are high,in which ripple cross-bedding is developed,and its intralayer and interlayer heterogeneity is strong.The sand body width and reservoir physical properties of Yan911 sublayer change greatly,the continuity of sand body is poor,and its plane heterogeneity is strong;the grain size,cement content and pore throat radius of sandstone in Yan911 sublayer have great change range,there are many types of interstitial materials,the physical properties are poor,and its micro heterogeneity is also strong.