甘肃庆城庄19井区上三叠统延长组长82亚油层组低渗透储层的地质特征

Geological characteristics of the low-permeability reservoir in the Chang8_2 reservoir subgroup in the Upper Triassic Yanchang Formation in the well Z19 area,Qingcheng,Gansu,China

长82亚油层组是甘肃庆城地区庄19井区上三叠统延长组中储集砂岩相对富集的层位,但砂岩低渗透性的特点显著,成为影响该区石油储产量增长的主要地质因素。结合前人的相关工作,通过钻井岩心观察、测井曲线分析、储层岩石实验测试等工作,详细地分析了庄19井区长82亚油层组低渗透储层的地质特征,认为沉积微相和压实作用、胶结作用是控制低渗透性储集砂岩发育和分布的主要地质因素,寻找以水下分流河道微相为代表的有利储集相带砂岩体是油气勘探的重要方向。

The Chang82 reservoir subgroup is a horizon containing relatively abundant reservoir sandstone in the Upper Triassic Yanchang Formaiton in the well Z19 area in Qingcheng, Gansu. However, as the sandstone has a pronounced low-permeability feature, it is the main geological factor which affects the growth of oil reserves in the area. According to the well core observation, log analysis and reservoir rock test, combined with previous work, the authors have analyzed in detail the geological characteristics of the low-per- meability reservoir of the Chang82 reservoir subgroup in the well Z19 area and think that the sedimentary microfacies, compaction and cementation are the main geological factors for controlling the development and distribution of low-permeability reservoir sandstone. To look for sandstone of the favorable reservoir facies belt represented by subaqueous distributary channel microfacies is an important direction for petroleum exploration.