四川盆地震旦系灯影组跨重大构造期油气成藏过程与成藏模式  

Process and model of hydrocarbon accumulation spanning major tectonic phases of Sinian Dengying Formation in the Sichuan Basin

作　　者：姜华[1,2] 李文正 黄士鹏 江青春[1] 翟秀芬[1] 谷志东[1] 谢武仁[1] 王瑞菊[1] JIANG Hua;LI Wenzheng;HUANG Shipeng;JIANG Qingchun;ZHAI Xiufen;GU Zhidong;XIE Wuren;WANG Ruiju(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;CNPC Key Laboratory of Natural Gas Accumulation and Development,Langfang,Hebei 065000,China;Chengdu University of Technology,Chengdu,Sichuan 610059,China;PetroChina Hangzhou Research Institute of Geology,Hangzhou,Zhejiang 310023,China)

机构地区：[1]中国石油勘探开发研究院,北京市100083 [2]中国石油天然气集团有限公司天然气成藏与开发重点实验室 [3]成都理工大学 [4]中国石油杭州地质研究院

出　　处：《天然气工业》2022年第5期11-23,共13页Natural Gas Industry

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);国家科技重大专项“下古生界—前寒武系碳酸盐岩油气成藏规律、关键技术及目标评价”(编号:2016ZX05004)。

摘　　要：跨重大构造期成藏是叠合盆地深层含油气系统最显著的成藏特征,研究跨重大构造期油气成藏的有效性和规模性对于深层海相碳酸盐岩油气勘探战略选区具有重要意义。为此,开展了以四川盆地上震旦统灯影组跨重大构造期变革为主线的盆地级古构造恢复和成藏模拟,研究了烃源灶演化,并恢复了成藏过程,构建了成藏模式。研究结果表明:①受多期构造演化控制,下寒武统筇竹寺组烃源灶热演化具有阶段性与差异性,灯影组圈闭不断调整改造,烃类运移与圈闭的动态配置控制油气富集。②筇竹寺组烃源岩普遍为高—过成熟,经历全过程生排烃,生成的原油发生热裂解生气并作为新的烃源灶;干酪根热解与原油裂解构成的烃源灶接力供烃体系控制着跨重大构造期油气聚集过程中的持续烃类补给。③灯影组跨重大构造期成藏类型可划分为原生型和次生型2类:原生型气藏为成油期已具备圈闭条件的气藏类型,可划分为构造型和岩性型2个亚类4个小类。其中,原位构造型长期继承性捕获油气,最有利于规模成藏;岩性型侧向遮挡条件好,可规模成藏,不受埋深控制;次生型气藏受较晚构造活动控制,可划分为3个亚类。结论认为,跨重大构造期成藏是深层、超深层古老海相碳酸盐岩成藏的基本条件,其规模性和有效性受构造演化控制作用显著;已发现四川盆地灯影组原位构造型气藏,揭示原位岩性型及次生型气藏将成为未来主要勘探方向。Hydrocarbon accumulation spanning major tectonic phases is the most significant hydrocarbon accumulation feature of a deep petroleum system in superimposed basins.Therefore,the study on the effectiveness and scale of hydrocarbon accumulation spanning major tectonic phases is of great significance to the strategic selection of deep marine carbonate oil and gas exploration areas.In this paper,basin-scale paleotectonic restoration and hydrocarbon accumulation simulation are carried out with the transformation spanning major tectonic phases of the Upper Sinian Dengying Formation in the Sichuan Basin as the main thread.In addition,the evolution of hydrocarbon source kitchen is studied,the hydrocarbon accumulation process is restored,and the hydrocarbon accumulation model is established.And the following research results are obtained.First,controlled by multi-stage tectonic evolution,the thermal evolution of hydrocarbon source kitchen in the Qiongzhusi Formation of Lower Cambrian is staged and differential.The traps of the Dengying Formation are constantly reformed and reworked.Oil and gas enrichment is controlled by hydrocarbon migration and dynamic trap configuration.Second,the source rocks of the Qiongzhusi Formation are generally in the high-and over-mature stage,having experienced the whole process of hydrocarbon generation and expulsion.The generated crude oil is thermally cracked into gas,acting as a new source kitchen.The continuous hydrocarbon supply in the process of oil and gas accumulation spanning major tectonic phases are controlled by the relay hydrocarbon supply system composed of kerogen pyrolysis and crude oil cracking.Third,the hydrocarbon accumulation spanning major tectonic phases of Dengying Formationcan be divided into primary type and secondary type.Primary type gas reservoirs have trap conditions in oil formation period,and they can be subdivided into 2 subclasses(i.e.,structural type and lithologic type)and 4 groups.Among them,the in-situ structural type has long-term inheritance of oil and ga

关 键 词：四川盆地 震旦系 灯影组 重大构造期 成藏类型 成藏过程 成藏模式 

分 类 号：P618.13[天文地球—矿床学]