准噶尔盆地西泉地区梧桐沟组低电阻率油层识别及分布

准噶尔盆地东部西泉地区上二叠统梧桐沟组储集层电阻率低,西泉以外的其他地区对应储集层都为中、高电阻,它们具有显著差别。西泉地区低电阻油层的电性表现为低电阻率、低密度、低自然伽马“三低”的特征。据岩心取样化验分析,低电阻油层的岩性为含大量塑性泥屑的中细粒岩屑杂砂岩,钙质夹层发育,为中孔、低渗储集层。泥质含量高及含水饱和度高是形成油层电阻率低的直接原因。通过测井解释识别储集层岩性,经过地震解释论证,目的层油藏是在低位和湖侵体系域沉积期间所形成的岩性圈闭中聚集而成,这种岩性油藏的规模和分布受控于岩性圈闭的发育,该区岩性圈闭的形成主要受控于沉积环境,这是导致产油储集层电性“三低”的本质因素。类比研究表明,该区同类岩性圈闭分布广泛、面积大,十分有利于岩性油藏的形成。

Identification and Distribution of Low-Resistivity Reservoir in Wutonggou Formation of Upper Permian in Xiquan Area,Junggar Basin

Low-resistivity reservoir of Wutonggou formation of the Upper Permian in Xiquan area in eastern Junggar basin is found rather than other areas with middle-high resistivity beyond Xiquan.The reservoir in Xiquan area is characterized by three lows,namely,low resistivity,low density and low gamma ray.And the lithology of low-resistivity reservoir is medium-fine lithic greywacke with lots of plastic pelolithic texture and calcareous interbeds,belonging to medium porosity and low permeability reservoir,according...