中国中西部前陆冲断褶皱带油气地质条件及勘探建议

Petroleum geologic conditions in foreland thrust fold belts in west-central China and proposals for exploration

郑和荣 李铁军 蔡立国 龙胜祥

Zheng Herong Li Tiejun Cai Liguo Long Shengxiang

中国中西部前陆冲断褶皱带地处欧亚大陆腹地,随欧亚大陆的增生而经历了元古代以来的多次构造旋回及多幕次的构造运动,其中喜马拉雅期的陆内造山作用使天山两侧、昆仑山北侧等中西部前陆冲断褶皱带最终定型。独特的构造背景和演化历史决定了中国中西部前陆冲断褶皱带主要发育以三叠系、侏罗系煤系和泥质岩为主的陆相烃源岩;长期的生排烃历史和晚期定型的构造圈闭决定了其多期成藏、晚期为主的成藏特征;而后期保存条件好、优质盖层发育的区带为油气成藏的有利地区。中国中西部前陆冲断褶皱带的特殊性决定了其在勘探上既要借鉴国外相似领域的勘探经验,更应加强中国前陆冲断褶皱带油气成藏条件、成藏特征的理论探索和相应的配套技术攻关。

The foreland thrust-fold belts in west-central China are located in the hinterland of Eurasia.They have experienced multiple tectonic cycles and multiple episodes of tectonic movements since Protozoic along with the accretion of Eurasia. The Himalayan intracontinental orogeny finalized the foreland thrust fold belts on both sides of Tian Shan and on northern side of Kunlun mountain.Continental source rocks,composed mainly of Triassic and Jurassic coal measures and argillaceous rocks,are developed in these foreland thrust-fold belts due to the unique tectonic setting and evolution history.The oil and gas pools in this area are characterized by multistage and mainly late stage hydrocarbon accumulations,as a result of long hydrocarbon generation and migration history and structural traps finalized in the late stage.Areas with good preservation conditions and well developed cap rocks are favorable for hydrocarbon accumulation.Efforts should be focused on theoretical study of the unique hydrocarbon accumulation conditions and features in the foreland thrust-fold belts in west-central China and on the relevant technological research,in addition to drawing on foreign exploration experiences in similar regions.

10.11743/ogg20040207