三塘湖盆地西峡沟东区低电阻油层储集特征及成因分析

Characteristics of low resistivity oil layers and its origin analysis in east area of Xixiagou in Santanghu basin

通过薄片鉴定、压汞等方法,结合测井、地层水分析资料对三塘湖盆地西峡沟东区西山窑组低电阻油层进行研究,结果表明,储层岩性主要为岩屑砂岩和长石岩屑砂岩,成分成熟度和结构成熟度低,储集空间以剩余粒间孔和溶蚀粒内孔为主,孔隙结构属粗喉细歪度型,沉积环境对低电阻地层的形成起到了关键作用。储层菱铁矿和黄铁矿的大量分布以及较高的地层水矿化度是该区低电阻油层形成的主要原因。

Through thin section identification and mercury injection, in combination with logging data and formation water analysis, the study on the low resistivity oil layers from Xishanyao formation in east area of Xi'xiagou of Santanghu basin was carried out. The results indicate that the main lithology is lithic sandstone and feldspathic lithic sandstone, with lower compositional and texture maturity, the reservoir space is dominated by residual intergranular pores and dissolution inner pores, and the sedimentary environment plays a key role in the formation of low resistivity oil layers, which is mainly due to the massive distribution of siderite and pyrite and high formation water salinity.