四川盆地8000m海相超深层天然气成藏条件及有利勘探区带  

Accumulation conditions and favorable exploration zones for natural gas in 8000 meters marine ultra-deep strata in the Sichuan basin

作　　者：黄士鹏[1] 姜华[1] 王铜山[1] 文龙[2] 管树巍[1] 曾富英[1] 朱光有[1] 田兴旺[2] 张天怡 Huang Shipeng;Jiang Hua;Wang Tongshan;Wen Long;Guan Shuwei;Zeng Fuying;Zhu Guangyou;Tian Xingwang;Zhang Tianyi(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;PetroChina Southwest Oil and Gas Field,Chengdu,Sichuan 610041,China;China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油西南油气田分公司,四川成都610041 [3]中国矿业大学(北京),北京100083

出　　处：《地质学报》2023年第5期1544-1560,共17页Acta Geologica Sinica

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目“海相碳酸盐岩成藏理论与勘探技术研究”(编号2021DJ05);重点盆地油气综合地质研究与勘探潜力评价(编号2022KT0405)联合资助的成果。

摘　　要：超深层(埋深>6000 m)是全球油气勘探的重大领域。当前,四川盆地天然气勘探已经突破8000 m超深层,但是盆地内8000 m超深层领域是否具备规模油气成藏条件、有利勘探区带分布在哪里等重大问题亟待破解。基于烃源岩、有利相带、储集层、圈闭类型、成藏组合等研究,对四川盆地8000 m超深层领域成藏条件与有利勘探区带进行了梳理和评价,得出以下认识:(1)四川盆地超深层领域主要发育于震旦系—中二叠统,且主要分布在环川中隆起带的川西坳陷、川北坳陷、川东褶皱带的深凹地区,其中川西北地区最具勘探潜力;(2)超深层烃源岩明显受凹陷或台内裂陷控制,主要发育陡山沱组、灯影组三段、麦地坪组和筇竹寺组等四套烃源岩,为8000 m超深层油气勘探提供了雄厚的物质基础;(3)震旦系—古生界主体发育(丘)滩孔隙型、岩溶孔洞型和白云岩孔隙型三类基本储层类型,三者相互叠加兼具裂缝改造形成多套规模储层,为超深层油气勘探提供了有利储集条件;(4)多套烃源岩和储层以走滑或逆冲断层相互沟通,主要发育下生上储、旁生侧储两种成藏组合,立体成藏特征明显;(5)岩性圈闭是震旦系—二叠系超深层气藏的主要圈闭类型,大型斜坡背景上发育的背斜或者鼻状构造叠合岩性体形成的构造-岩性圈闭也是重要的勘探对象;(6)8000 m超深层发育六大领域9个有利勘探区带,累计勘探面积超4.5万km^(2),资源量约3×10^(12)~5×10^(12)m^(3)。研究认识对于四川盆地超深层天然气勘探具有重要理论和现实意义。The ultra-deep layer with depth>6000 m is a major field of global oil and gas exploration.At present,the gas exploration in Sichuan basin has broken through the 8000 m ultra-deep layer,but the scientific questions such as whether the 8000 m ultra-deep field in the basin has the conditions for large-scale gas field accumulation,and where the favorable exploration zones are distributed have not been clearly answered.Based on the study of source rocks,favorable facies zone,reservoir,trap types,and reservoir forming assemblages,the reservoir forming conditions and favorable exploration zones in the 8000 m ultra-deep strata of Sichuan basin were evaluated in detail,and the following conclusions were obtained:(1)the ultra-deep strata of Sichuan basin is mainly developed in the Sinian-Middle Permian,and is mainly distributed in the deep western depression,northern depression and the fold belt in eastern Sichuan.Among them the western depression has the largest exploration potential;(2)the ultra-deep source rocks are obviously controlled by depressions or intra platform rifts,and mainly develop four sets of source rocks,including Doushantuo Formation(Fm),third Member of Dengying Fm,Maidiping Fm and Qiongzhusi Fm,which provide an abundant material basis for 8000 m ultra-deep gas exploration;(3)there are three basic reservoir types in the main body of Sinian-Paleozoic layer,the beach(mound)controlling porous type,karst vuggy type and dolomite porous type,which are superimposed with each other and combined with fracture altered to form large-scale multiple reservoir layers,providing favorable reservoir conditions for ultra-deep gas exploration;(4)many sets of source rocks and reservoirs communicate with each other by strike slip or thrust faults,and mainly develop two kinds of reservoir forming combinations of lower source and upper reservoir,and paraegenic and lateral reservoir assemblages forming obvious three-dimensional reservoir characteristics;(5)lithologic trap is the main trap type of ultra-deep Sinian-Permian gas r

关 键 词：8000m超深层 成藏条件 有利区带 震旦系 古生界 海相 四川盆地 

分 类 号：P618.13[天文地球—矿床学]