Unveiling the Oldest Industrial Shale Gas Reservoir:Insights for the Enrichment Pattern and Exploration Direction of Lower Cambrian Shale Gas in the Sichuan Basin

扫码查看

原文链接

万方数据
维普

外文摘要：The lower Cambrian Qiongzhusi((€)1q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388 × 105 m3·d-1)from well Z201 in the Deyang-Anyue rift trough(DART),marking an exploration breakthrough of the world's oldest industrial shale gas reser-voir.However,the shale gas enrichment mechanism within the DART is not fully understood.This study reviews the formation of the Qiongzhusi shale gas reservoirs within the DART by comparing them with cotemporaneous deposits outside the DART,and several findings are presented.The gas production interval was correlated with the main phase of the Cambrian explosion(lower Cambrian stage 3).In the early Cambrian ecosystem,dominant animals likely accelerated the settling rates of organic matter(OM)in the upper 1st member of (€)1q((€)1q12)by feeding on small planktonic organisms and producing larger organic fragments and fecal pellets.High primary productivity and euxinic con-ditions contributed to OM enrichment in the lower 1st member of (€)1q(€1q11).Additionally,shale reservoirs inside the DART demonstrated better properties than those outside in terms of thickness,brittle minerals,gas content,and porosity.In particular,the abundant OM pores inside the DART facil-itated shale gas enrichment,whereas the higher thermal maturity of the shales outside the DART pos-sibly led to the graphitization and collapse of some OM pores.Meanwhile,the overpressure of high-production wells inside the DART generally reflects better shale gas preservation,benefiting from the shale's self-sealing nature,"upper capping and lower plugging"configuration,and limited faults and microfractures.Considering these insights,we introduced a"ternary enrichment"model for the Qiongzhusi shale gas.Although the current high gas production of Z201 was found at the reservoir 3,two additional reservoirs were identified with significant potential,thus suggesting a"multilayer stereoscopic development"strategy in future shale gas exploration within the DART.

外文关键词：

Ultradeep shale gasSichuan BasinQiongzhusi shaleDeyang-Anyue rift troughWell Z201Ternary enrichmentMultilayer stereoscopic development

作者：

Caineng Zou、Zhengfu Zhao、Songqi Pan、Jia Yin、Guanwen Lu、Fangliang Fu、Ming Yuan、Hanlin Liu、Guosheng Zhang、Cui Luo、Wei Wang、Zhenhua Jing

展开 >

作者单位：

Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China

College of Geoscience and Survey Engineering,China University of Mining and Technology,Beijing 100083,China

School of Earth and Space Sciences,Peking University,Beijing 100871,China

PetroChina Shenzhen New Energy Research Institute,Shenzhen 518054,China

School of Energy and Resource,China University of Geosciences(Beijing),Beijing 100083,China

Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China

展开 >

出版年：

2024

DOI：

10.1016/j.eng.2024.03.007

工程(英文)

CSTPCDEI

ISSN：2095-8099

年,卷(期)：2024.42(11)