【摘要】 酒西盆地青西坳陷下白垩统下沟组的纹层状泥质白云岩和白云质泥岩已被证实勘探前景良好。这套储集岩的颗粒细小 ,岩性致密 ,基质孔隙度低 ,实验分析表明 ,其泥质物中的主要成分是泥级斜长石。详细的岩石学研究表明 ,这类斜长石属晕长石 ,是火山物质经流水搬运 ,在半干旱气候下的碱性湖水中沉积后 ,经浅埋藏深度改造而成。青西坳陷下沟组泥级斜长石的大量存在 ,使其泥质纹层具有高的弹性 ,在区域构造应力作用下易形成纹层间滑脱缝和斜交缝 ,奠定了发育构造裂缝的物质基础 ,而构造微裂缝与沸石溶孔沟通 ,使下沟组形成了非砂岩的裂缝 孔隙型储集层。这类新型储集层的出现预示着酒西盆地的邻区和其它类似盆地具有良好的油气勘探前景。图 1照片 8参 8更多还原

【Abstract】 The laminated muddy dolomite and dolomite mudstones of Xiagou Formati on in the Lower Cretaceous, Qingxi depression in Jiuxi basin have very bright pr ospect. In spite of being tight and low porous, but they are good reservoir rocks proved by the recent exploration and production. The detail lithologic analysis shows that the mud portion of the rocks is mainly composed of clay size plagioclase. The detail petrography stud y further confirms the plagioclase particles, which are mostly of peristerite an d came from deposition processed volcanic matter, deposited in a semi arid lak e and suffered from shallow burial. The plagioclase components in laminated mudd y dolomite and dolomite mudstones make the rocks much more plastic and brittle, so that regional stress easily caused the sliding and oblique fractures and micr o fractures. Therefore, this is a new type of non sandstone reservoirs rock. T he important find to this type of reservoir rocks implies oil and gas will be di scovered in adjacent area of Jiuxi basin and other analogous basins in the futur e.更多还原