摘要
综合利用地震、钻井、测井及岩心分析化验资料,分析了四川盆地西南缘天宫堂构造奥陶系五峰组—志留系龙马溪组的构造、沉积、储层及可改造性等基本地质特征,探讨了页岩气富集主控因素及成藏模式。研究结果表明:①天宫堂构造优质页岩集中分布在五峰组—龙马溪组龙一_(1)亚段,Ⅰ类储层主要发育于龙一_(1)^(1)—龙一_(1)^(3)小层,厚度为0.8~17.0 m,具典型的高TOC含量、含气性好、高脆性矿物的特征。②天宫堂构造经历了晚白垩世前快速沉降、深埋藏和大量排烃阶段,形成早期富集型超压页岩气藏;晚白垩世后经2期抬升改造,早期富集型超压页岩气藏逐步向高压—常压页岩气藏调整。③研究区保存条件受地层倾角与宫1号断层的影响,造成不同构造部位页岩气差异富集。④研究区为“早期深埋藏促富集,后期隆升调富集、保存条件控富集”的背斜构造型成藏模式,构造南西翼是下步页岩气勘探开发的潜在有利区。
The data of seismic,drilling,logging and core analysis and test were comprehensively used to study the structure,deposition and basic reservoir geological characteristics of Ordovician Wufeng-Silurian Longmaxi Formation in Tiangongtang structure in southwestern margin of Sichuan Basin,and the main controlling factors of shale gas enrichment and accumulation model were discussed.The results show that:(1)The high-quality shale in Tiangongtang structure is mainly developed in O_(3)w-S_(1)l_(1-1).TypeⅠreservoir is mainly developed in S_(1)l_(1-1-1)-S_(1)l_(1-1-3) layers,with a thickness of 0.8-17.0 m,and characterized by high TOC content,good gas-bearing property and highly brittle minerals.(2)Tiangongtang structure has experienced rapid subsidence,deep burial and a large amount of hydrocarbon expulsion before the Late Cretaceous,forming an early enriched overpressure shale gas reservoir.After the Late Cretaceous,it was uplifted and reformed in two phases,and the early enriched overpressure shale gas reservoir gradually transformed to high pressure-normal pressure shale gas reservoir.(3)The preservation conditions of Tiangongtang structure are affected by stratigraphic dip angle and Gong-1 fault,resulting in differential enrichment of shale gas in different structural zones.(4)Tiangongtang structure is an anticline structure-type accumulation model of“early deep burial promotes enrichment,later uplift adjusts enrichment,and preservation conditions control enrichment”.The southwest tip of the structure is a potential favorable area for next shale gas exploration and development.
作者
张梦琳
李郭琴
何嘉
衡德
ZHANG Menglin;LI Guoqin;HE Jia;HENG De(Research Institute of Geological Exploration and Development,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Chengdu 610051,China;Sichuan Changning Natural Gas Development Co.,Ltd.,PetroChina Southwest Oil&Gas Field Company,Chengdu 610000,China)
出处
《岩性油气藏》
CSCD
北大核心
2022年第2期141-151,共11页
Lithologic Reservoirs
基金
国家自然科学基金“海相深层油气富集机理与关键工程技术基础研究”(编号:U19B6003)资助。
关键词
富集主控因素
页岩气
五峰组—龙马溪组
奥陶系
志留系
天宫堂构造
川西南
main controlling factors of enrichment
shale gas
Wufeng-Longmaxi Formation
Ordovician
Silu‐rian
Tiangongtang structure
southwestern Sichuan Basin
