四川盆地晚古生代构造-热事件及其与油气关系  

Late Paleozoic tectono-thermal event and its relationship to oil and gas in Sichuan Basin

作　　者：孙自明 卞昌蓉[1,2] SUN Ziming;BIAN Changrong(Sinopec Key Laboratory of Geology and Resources in Deep Stratum,Beijing 102206,China;Sinopec Petroleum Exploration and Production Research Institute,Beijing 100083,China)

机构地区：[1]中国石化深部地质与资源重点实验室,北京102206 [2]中国石化石油勘探开发研究院,北京100083

出　　处：《世界石油工业》2024年第6期19-29,共11页World Petroleum Industry

基　　金：国家自然科学基金企业重点联合基金“盆地深部地质作用过程与资源效应”(U20B6001);国家自然科学基金企业创新发展联合基金项目“海相深层油气富集机理与关键工程技术基础研究“(U19B6003);中国石化科技攻关项目”四川盆地寒武系洗象池群—奥陶系宝塔组天然气富集规律与目标优选”(P21042-2)。

摘　　要：构造-热事件是地球深部强烈构造活动导致岩石圈发生构造变形和变位而引起深源流体上涌的地质现象,为探讨构造-热事件与油气的关系,以四川盆地为例,研究了构造-热事件对油气成藏条件的影响。结果表明:受二叠纪峨眉山地幔柱上涌和南秦岭洋区域岩石圈伸展作用的共同控制,四川盆地及邻区晚古生代经历了一次明显的构造-热事件,对油气成藏条件的影响主要表现在:①形成了多种类型的油气储层,包括与火山喷发相关的火成岩储层、与区域地壳隆升有关的中二叠统茅口组碳酸盐岩岩溶储层、以及与区域构造伸展有关的上二叠统—下三叠统礁滩相灰岩储层和构造-热液白云岩储层等;②快速产生了较高的古地温异常,加速了震旦系—中二叠统烃源岩的成熟演化进程;③提供了油气运移的动力和通道;④促使油气相态发生转化;⑤使油气成藏期提前,延长了古油气藏的保存时间,相应地增加了被后期构造改造或破坏的风险。因此,晚古生代构造-热事件对四川盆地震旦系—下三叠统油气成藏条件、成藏过程、油气相态转化和保存等均具有重要的影响。Tectono-thermal event is a common geological phenomenon of deep-sourced fluid upwelling caused by tectonic deformation and dislocation of lithospheric plate triggered by strong tectonic activity in deep earth.In order to discuss the relationship between tectono-thermal event and oil and gas,taking Sichuan Basin as an example,systemic method was used to investigate the influence of tectono-thermal event on hydrocarbon accumulation conditions.The results show that a tectono-thermal event induced by upwelling of the Emeishan mantle plume and extension of the southern Qinling oceanic lithospheric plate dramatically happened in Sichuan Basin and its adjacent areas in late Paleozoic,which had an important impact on hydrocarbon accumulation conditions.It is mainly shown as follows:①Various types of oil and gas reservoirs were formed,including the igneous rock reservoirs associated with volcanic eruption,the carbonate karst reservoirs of the Middle Permian Maokou formation associated with regional crustal uplift,and the reef-shoal limestone reservoirs and the tectono-hydrothermal dolomite reservoirs related to tectonic extension,etc.②The high paleo-geothermal anomaly is rapidly produced,which accelerates the mature evolution process of Sinian-Middle Permian source rocks.③The driving force and pathways for oil and gas migration are provided.④The phase/state transformation of oil and gas is promoted.⑤The hydrocarbon accumulation times are pushed ahead,and the retention duration of paleo-reservoirs is prolonged,which increases the risks reformed and damaged by late tectonic movements.In conclusion,the Late Paleozoic tectono-thermal event has momentous impacts on hydrocarbon accumulation conditions,accumulation processes,phase transformation and preservation of Sinian-Lower Triassic Systems in Sichuan Basin.

关 键 词：晚古生代 构造-热事件 油气成藏 四川盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]