四川盆地寒武系筇竹寺组新类型页岩气形成机理与勘探突破  

Formation mechanisms and exploration breakthroughs of new type of shale gas in Cambrian Qiongzhusi Formation,Sichuan Basin,SW China

作　　者：郭彤楼[1] 邓虎成[2] 赵爽[1] 魏力民[1] 何建华 GUO Tonglou;DENG Hucheng;ZHAO Shuang;WEI Limin;HE Jianhua(Southwest Petroleum Branch,Sinopec,Chengdu 610041,China;Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国石化西南油气分公司,成都610041 [2]成都理工大学,成都610059

出　　处：《石油勘探与开发》2025年第1期57-69,共13页Petroleum Exploration and Development

基　　金：中国石化重大科技项目“川西南筇竹寺组页岩气精细评价及目标优选”(P22081);国家自然科学基金企业创新发展联合基金集成项目“三大盆地深层—超深层海相油气高效勘探开发基础研究”(U24B60001)。

摘　　要：基于四川盆地寒武系筇竹寺组页岩岩心、测井、地震和生产等资料,采用矿物扫描、有机与无机地球化学分析、突破压力及三轴力学测试等方法,开展筇竹寺组储层基本地质特征研究,分析筇竹寺组页岩气富集高产条件、页岩气形成机理和富集模式。研究表明:①深水富有机质和浅水低有机质两类粉砂质页岩都具有很好的含气性;②页岩脆性矿物组成具有长石、石英含量相当的特征;③页岩孔隙以无机质孔为主,有机质孔含量低,孔隙发育受长英质矿物与总有机碳含量(TOC)共同控制;④页岩有机质类型为Ⅰ型,成烃生物为藻类和疑源类,成熟度高,生烃潜力高;⑤深水相、浅水相页岩气分别具有原地和混合成气的特点。⑥筇竹寺组页岩气富集基本规律是“TOC控藏、无机质孔控富”,富集模式为以ZY2井为代表的富有机质页岩“三高一超”(高TOC、高长英质矿物含量、高无机质孔、地层超压)原地富集模式和以JS103井为代表的低有机质页岩“两高一中一低”(高长英质、高地层压力、中无机质孔、低TOC)原地+输导层富集模式,是有别于志留系龙马溪组的新类型页岩气。研究成果丰富了深层—超深层页岩气形成机理,部署的多口探井实现页岩气勘探重大突破。The basic geological characteristics of the Qiongzhusi Formation reservoirs and conditions for shale gas enrichment and high-yield were studied by using methods such as mineral scanning,organic and inorganic geochemistry,breakthrough pressure and triaxial mechanics testing based on the core,logging,seismic and production data.(1)Both types of silty shale,rich in organic matter in deep water and low in organic matter in shallow water,have good gas bearing properties.(2)The brittle mineral composition of shale has the characteristic of equivalent content of feldspar and quartz.(3)The pores are mainly inorganic pores with a small amount of organic pores.Pore development primarily hinges on a synergy between felsic minerals and total organic carbon content(TOC).(4)Dominated by Type I organic matters,the hydrocarbon generating organisms are algae and acritarch,with high maturity and high hydrocarbon generation potential.(5)Deep-and shallow-water shale gas exhibit in-situ and mixed gas generation characteristics,respectively.(6)The basic law of shale gas enrichment in the Qiongzhusi Formation was proposed as“TOC controlled accumulation and inorganic pore controlled enrichment”,which includes the in-situ enrichment model of“three highs and one over”(high TOC,high felsic mineral content,high inorganic pore content,overpressured formation)for organic rich shale represented by Well ZY2,and the in-situ+carrier bed enrichment model of“two highs,one medium and one low”(high felsic content,high formation pressure,medium inorganic pore content,low TOC)for organic-poor shale gas represented by Well JS103.It is a new type of shale gas that is different from the Longmaxi Formation,enriching the formation mechanism of deep and ultra-deep shale gas.The deployment of multiple exploration wells has achieved significant breakthroughs in shale gas exploration.

关 键 词：四川盆地 寒武系 筇竹寺组 页岩气 无机质孔 长英质 富集模式 

分 类 号：TE122.3[石油与天然气工程—油气勘探]