鄂尔多斯盆地下寺湾地区延长组长_7段页岩储层特征及评价

Characteristics and Evaluation of Shale Reservoir in Chang 7 Member of Yanchang Formation,Xiashiwan Area,Ordos Basin

通过分析页岩分布规律,页岩埋藏深度、厚度及微构造,有机质丰度和有机质热演化程度以及孔隙度、渗透率和微裂缝等成藏条件,认为研究区中生界三叠系延长组长_7段页岩具备了页岩气成藏的条件。该区页岩气勘探选区评价的关键地质参数主要包括页岩埋藏深度及厚度、有机碳含量、成熟度、微裂缝发育程度和气测异常显示等。根据页岩气藏成藏条件及勘探过程中钻井气测异常的分布情况,预测研究区长_7段页岩气富集区,为后续页岩气甜点识别提供地质依据。

Based on the analysis of shale distribution, shale buried depth＆thickness, micro structure, organic mat- ter abundance, thermal evolution of organic matter, degree of porosity, permeability and micro cracks accumulation conditions, it is concluded that member 7 shale of the mesozoic Yanchang Formation is with shale gas accumulation conditions. The key geological evaluation parameters of shale gas exploration of this district include shale buried depth and thickness, organic carbon content, maturity, micro fractures and abnormal display of gas measurement, etc. According to the conditions of shale gas reservoir formation and the distribution of abnormal gas logging in the exploration process, it is predicted that Chang 7 section in the study area is the shale gas accumulation area, which can provides geological basis for subsequent shale gas dessert identification.