四川盆地二叠系栖霞组、茅口组白云岩储层特征、成因和分布

作    者:胡安平1,2, 潘立银1,2, 郝 毅1,2, 沈安江1,2, 谷明峰1,2
单    位:(1 中国石油杭州地质研究院; 2 中国石油天然气集团公司碳酸盐岩储层重点实验室)
基金项目:受国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05004-002)资助
摘    要:
基于6个露头剖面和10口井岩心的观察,近百口井的老井复查,500余个岩石薄片的观察和80余件样品的同位素、微量元素、稀土元素、流体包裹体、同位素定年等实验分析,取得三个方面的新认识:(1)栖霞组、茅口组白云岩储层的发育具有普遍性和一定规模,可识别出孔隙型、孔洞型和复合型等三类白云岩储层,晶间孔、晶间溶孔和溶蚀孔洞是主要的储集空间类型;(2)滩相沉积、早表生期暴露溶蚀和埋藏期构造-热液事件是栖霞组、茅口组白云岩储层发育的三个主控因素;(3)栖霞组、茅口组白云岩储层的分布有规律可循,垂向上,白云岩储层主要分布于栖霞组二段和茅口组二段、三段,平面上,栖霞组二段白云岩储层主要分布于川西及川中地区,茅口组二段、三段白云岩储层主要分布于川西、川中和川南地区。
关键词:四川盆地;二叠纪;栖霞组;茅口组;白云岩储层;储层成因;构造-热液事件

Origin, Characteristics and Distribution of Dolostone Reservoir in Qixia Formation and Maokou Formation, Sichuan Basin, China

Author's Name: Hu Anping, Pan Liyin, Hao Yi, Shen Anjiang, Gu Mingfeng
Institution: PetroChina Hangzhou Research Institute of Geology
Abstract:
Carbonates of Middle Permian Qixia Formation and Maokou Formation had been gas-producing reservoir mainly in southern Sichuan Basin in the last century. It had been accepted that these reservoirs were fractured limestones, resulting in low gas ratio(5.80%) and failure to discover uncompartmentalized gas fields. Based on the investigations and analysis of 6 outcrops, 10 exploration wells, 500 thin sections, and other data of isotope, minor element, rare earth element, fluid inclusion and isotopic age get from 80 samples, three findings are presented as follows: (1) Dolostones with intercrystaline pores, dissolution-enlarged intercrystaline pores and vugs are widespread in Qixia Formation and Maokou Formation; (2) Dolostone reservoirs was predominantly constrained by shoal water carbonate sediments, and the dissolution in freshwater during early diagenetic processes, and the tectonic and hydrothermal events during burial; (3) The dolostone reservoirs are mainly distributed in the 2nd member of Qixia Formation in west and central Sichuan Basin, and in the 2nd and 3rd member of Maokou Formation in west, central and south Sichuan Basin.
Keywords: Permian; Qixia Formation; Maokou Formation; Dolostone reservoir; Tectonic event; Hydrothermal event; Sichuan Basin
投稿时间: 2017-06-27  
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