四川盆地加里东古隆起构造演化与油气聚集的关系  

Tectonic evolution of Caledonian paleohigh in the Sichuan Basin and its relationship with hydrocarbon accumulation

作　　者：李伟[1] 易海永[2] 胡望水[3] 杨庚[1] 熊璇 

机构地区：[1]中国石油勘探开发研究院 [2]中国石油西南油气田公司 [3]长江大学

出　　处：《天然气工业》2014年第3期8-15,共8页Natural Gas Industry

基　　金：国家科技重大专项(编号:2011ZX05004)

摘　　要：加里东古隆起是四川盆地中西部震旦系及下古生界重要的含气领域,近年来在该区连续取得了天然气勘探突破。为厘清该古隆起构造演化与油气聚集的关系,基于前人的研究成果,开展了新一轮的研究工作。结果表明:①该古隆起自发育以来,经历了震旦纪晚期的整体掀斜与雏形发育、寒武纪—奥陶纪的同沉积隆升、志留纪的联合隆升、泥盆纪—石炭纪的长期隆升剥蚀、二叠纪的整体沉降沉积与区域盖层形成、三叠纪—侏罗纪的古隆起东段高点南迁、白垩纪—新近纪的古隆起西段强烈变形等7个主要演化阶段;②震旦系—下古生界的油气聚集,经历了志留纪—三叠纪古油藏形成、侏罗纪—渐新世古气藏发育与中新世以来的气藏差异演化等3个主要时期;③震旦系—下古生界古油藏和古气藏主要发育于乐山—资阳—高石梯—龙女寺一带及其以北地区,尤其是喜马拉雅晚期以来,古隆起西段构造运动强烈,而古隆起东段构造运动相对稳定,更有利于天然气的聚集与保存。结论认为,高石梯—磨溪—龙女寺构造带及其北翼,不仅是下古生界构造圈闭型气藏最有利的发育区,而且也是寒武系与奥陶系顶部岩溶型岩性圈闭气藏最有利的发育区;后者将成为该区重要的油气勘探对象。The Caledonian paleohigh is an important gas exploration domain in the Sinian and Lower Paleozoic in the western-central Sichuan Basin where gas discoveries are successively obtained in recent years.In order to clarify the relationship between the tectonic evolution of this paleohigh and hydrocarbon accumulation,we carried out a new round of research based on the previous study results.The evolution history of this paleohigh can be divided into 7 episodes：the Late Sinian overall tilting and the youth form development of this paleohigh,the Cambrian-Ordovician syndepositional uplifting,the Silurian joint uplifting,the Devonian-Carboniferous uplifting and erosion,the Permian overall subsidence and deposition of regional caprock,the Triassic-Jurassic migration of structural high of the eastern segment of this paloehigh,and Cretaceous-Neogene strong deformation of the western segment of this paleohigh.The hydrocarbon accumulation in the Sinian-Lower Paleozoic experienced three evolution stages including the formation of ancient oil reservoirs in the Silurian-Triassic period,the development of the paleo-oil reservoirs in the Jurassic-Oligocene period,and differential evolution of gas reservoirs since the Miocene era.The Sinian-Lower Paleozoic paleo-reservoirs mainly occur along the Leshan-Ziyang-Gaoshiti-Longnüsi zone and the area to its north.The tectonic movement of the western segment of the paleohigh was strong,while its eastern segment was relatively stable since the late Himalayan epoch,a situation being favorable for gas accumulation and preservation.It is believed that the Gaoshiti-Moxi Longnüsi structural belt and its northern limb are not only favorable for the development of gas reservoirs of structural type in the Lower Paleozoic but also for gas reservoirs of karstic-lithologic type on the top of the Cambrian and Ordovician.The latter will be the major exploration target in the future.

关 键 词：四川盆地中西部 加里东古隆起 构造演化 震旦纪 寒武纪 早古生代 油气聚集 气藏形成 勘探区 

分 类 号：P618.13[天文地球—矿床学]