西峰油田长8油藏高阻水层影响因素探讨

Investigation on factors of high resistivity water in Xifeng oilfield Chang 8 reservoir

鄂尔多斯盆地西峰油田长8油藏储量资源丰富,建产潜力大,是该区增储上产的主要层位之一,近年来由于高阻水层现象的出现,难以有效识别油水层,一定程度上增大了产建风险,为了准确识别长8储层流体性质,搞清高阻水层成因,紧密结合西峰庄36区长8油藏实际情况,通过大量实例,综合应用岩性、物性等分析化验资料、常规测井及核磁共振等测试资料,确定了碳酸盐含量高、绿泥石含量高、结构泥质的存在、物性及孔隙结构差为导致水层电阻率与油层电阻率差异小的主要原因,从而扩展了油水层识别方法,对推动该区增储上产具有重要的现实意义。

With rich reserves and great potential of production capacity, Chang 8 reservoir of Xifeng oilfield in Ordos basin is one of the main area for increasing reserves and production.Due to the high resistance layer phenomenon appeared in recent years,it is difficult to identify oil and water layer effectively,to some extent, which increases the risk of capacity building.In order to accurately identify the Chang 8 reservoir fluid properties, clarify the causes of high resistivity water layer,lab data,conventional logging,NMR experiments and other test data are analyzed, in close connection with the actual situation of Chang 8 reservoir in Zhuang36,through a large number of instances,integrated application of lithology,physical property.The results show that high content of carbonate and chlorite, the existence of structural shale,poor physical properties and pore structure of mud are the main causes of small difference of water layer resistivity and reservoir resistivity, and thus expand the oil and water layer identification methods, which has important practical significance on promoting reserves and production in this region.