鄂尔多斯盆地上里塬地区延长组长7油层组储层特征

Characteristics of Chang 7oil group of Yanchang Formation in Shangliyuan area of Ordos Basin,China

以物性分析、铸体薄片分析及压汞分析等实验室数据为基础,对鄂尔多斯盆地上里塬地区下三叠统延长组长7油层组致密油储层特征进行了系统研究,结果表明长7油层组储层主要为浊流沉积所形成的浊积砂岩,岩石类型为长石砂岩和岩屑长石砂岩,填隙物含量高;储集砂岩经历了压实、压溶、绿泥石膜、溶解和破裂等成岩改造,微裂缝较发育。储集砂体孔隙结构表现为:孔隙半径平均为40.84μm,喉道宽度平均为13.22μm,具有中孔细喉特点。以上特点导致研究区储层具有储量规模大、定向井开发单产低、体积压裂能有效提高水平井单井产量的特征。

Based on the laboratory data of property analysis,casting thin analysis and mercury analysis,this paper studies the reservoir characteristics of Chang 7oil group of Yanchang Formation in the Shangliyuan area of Ordos Basin.The results show that the reservoir of Chang 7oil group in research region are mainly turbidite standstone formed by turbidity deposits.The rock types include feldspathic sandstone and lithic feldspathic sandstone,and the interstitial material content is high.The reservoir sandstone has experienced diagenetic transformation such as compaction,pressure soluble,chlorite membrane rupture,dissolution and micro-cracks,etc.The pore structure of the sandbody shows the characteristic of mesoporous thin throat,the average pore radius is 40.84μm,and the average width of the throat is 13.22μm.These characteristics make the reservoirs have large reserves in study area and low yields of directional drilling development,and the volume pressure can effectively improve the well production in horizontal wells.