鄂尔多斯盆地西南部上古生界致密砂岩气储层成岩演化特征及物性演化  

Characteristics of the diagenetic evolution of tight sandstone gas reservoir and its property in the Upper Paleozoic erathem in southwestern Ordos Basin

作　　者：朱瑞静[1,2] 李荣西 刘新社[3] 杨鸣一 覃小丽 吴小力[1] 赵帮胜[1] 刘福田 ZHU Rui-jing;LI Rong-xi;LIU Xin-she;YANG Ming-yi;QIN Xiao-li;WU Xiao-li;ZHAO Bang-sheng;LIU Fu-tian(School of Earth Science and Resource,Chang'an University,Xi'an 710054,China;Shanxi Institute of Engineering Technology,Yangquan 045000,Shanxi,China;Exploration Division,Changqing Oilfield Branch of Petro China,Xi'an 710018,China)

机构地区：[1]长安大学地球科学与资源学院,西安710054 [2]山西工程技术学院,山西阳泉045000 [3]中国石油长庆油田分公司勘探事业部,西安710018

出　　处：《兰州大学学报（自然科学版）》2021年第5期637-649,658,共14页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41772118);长庆油田2018年科研项目(41172118);中央高校基本科研业务费专项资金项目(300102278107,300102279206)。

摘　　要：为研究鄂尔多斯盆地西南部上古生界二叠系气藏致密砂岩储层特征,基于探井岩心、地质资料和分析测试成果,明确研究区二叠系沉积特征,应用岩石薄片、扫描电镜、阴极发光、流体包裹体等实验技术,对储层岩石学、成岩作用类型及特征、流体包裹体和成岩流体特征进行分析,以此划分成岩作用期次,明晰不同期次成岩演化序列,探讨储层致密化过程和物性演化.结果表明,研究区盒8段和山1段地层为滨浅湖、三角洲前缘和三角洲平原沉积,岩石类型主要为石英砂岩,次为长石石英砂岩和岩屑石英砂岩,少量岩屑砂岩、岩屑长石砂岩和长石岩屑砂岩;孔隙以溶蚀孔为主要储集空间,储层成岩作用特征为强压实、多期次硅质胶结和钙质胶结物,大量黏土矿物,溶蚀程度强,裂缝和裂隙发育;储层盒8和山1层段分布的两期包裹体分别记录了早期天然气生成并运移进入储层和晚期天然气聚集成藏;结合成岩演化序列、构造埋藏史和成藏史,研究区储层经历了成岩作用的晚成岩期,发生两期油气充注;储层物性演化史表明压实作用和胶结作用对储层致密的重要性,研究区具有先成藏后致密或者边成藏边致密的特征.To investigate into the tight sandstone gas reservoir characteristics of the Permian in Upper Paleozoic erathem southwestern of Ordos Basin,based on the core wells,geological data and analysis apart from the test results,the sedimentary characteristics of the study area were clarified.Through the rock thin section,scanning electron microscope,cathodoluminescence,fluid inclusions and other experimental technologies,the characteristics of reservoir lithology,physical property and diagenesis types were researched,diagenesis activity times divided,the sequence of different diagenetic evolution cleared and the formation densification process and property of evolution were studied.The results showed that stratum of He 8 member and Shan 1 member in the study area were of shore shallow lake,delta front and plain deposits and the rock types were mainly quartz sandstone,followed by feldspar quartz sandstone and lithic quartz sandstone,and a small amount of lithic sandstone,lithic feldspar sandstone and feldspar lithic sandstone.Dissolution pores formed the main reservoir space,and the characteristics of diagenesis in the reservoir was of strong compaction,in stages of siliceous cementation and calcareous cement,with a large number of clay minerals,and a strong degree of dissolution,growth of fracture and cracks.Two phases of inclusions distributed in the reservoir He 8 and Shan 1 recorded the generation and migration of early natural gas into the reservoir and the accumulation of late natural gas.Combined with the diagenetic evolutionary sequence,structural burial history and accumulation history,the reservoir in the study area reached the late diagenetic stage of diagenesis,and two periods of oil and gas filling occurred.The property of reservoir evolution history showed that compaction and cementation were of great importance to the reservoir density.The study area had the characteristics that the reservoir first formed and then became dense,or that the reservoir formed and became dense at the same time.

关 键 词：致密砂岩 储集层 成岩演化 上古生界 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]