吐哈盆地胜北凹陷浅层油气源与成藏研究

RESEARCH OF THE OIL-GAS SOURCE AND FORMATION OF THE POOLS IN THE SHALLOW BED OF THE SHENGBEI SAG, THE TUHA BASIN

李延钧 陈义才 张艳云 郭秀英 杨军

Li Yanjun Chen Yicai Zhang Yanyun Guo Xiuying Yangjun

西南石油大学, 成都, 610500 2. 成都理工大学, 成都, 610059

South-west Petroleum Institute, Chengdu, Sichuan, 610500, China 2. Chengdu Science and Engineering University, Chengdu, Sichuan 610059, China

通过原油碳同位素、轻烃和油岩生标物综合对比证实,吐哈盆地胜北凹陷浅层上侏罗统喀拉扎组—下白垩统火焰山群油气主要为中下侏罗统水西沟群煤系烃源岩所生,同时一些地区混有中侏罗统七克台组湖相泥岩所形成的烃类。研究表明穿越中侏罗统七克台组—上侏罗统齐古组区域盖层的断裂是浅层油气运聚成藏的关键。不同地区浅层油气运聚时期和来源方式不同,具有"分段捕获"的成藏特征。其中红南—连木沁构造带浅层油气运聚较晚,主要来源于中侏罗统已聚集油气的再分配,为次生油气藏;而胜北构造带浅层上侏罗统喀拉扎组油气运聚较早,主要捕获了中下侏罗统水西沟群煤系早期低熟生烃产物。

By the comprehension correlation of the crude oil carbon isotope,light hydrocarbon,oil-rock biomarker,the paper indicates that the oil-gas in the shallow bed are mainly provided by the Shuixigou Group coal seam of Middle-Lower Jurassic series,and some areas are mixed with the hydrocarbons generated from lake facie shale of the Middle Jurassic Qiketai Formation in the Shengbei Sag,Tuha Basin.In the meantime,it shows that the fault passed through the regional cover(J2q-J3q) is a key to migration and collection of the oil-gas in the shallow bed.Furthermore,the author thinks that the time and way of the oil-gas migration and collection are different in the different areas,which is the characteristic of capturing oil-gas in stags to form pool,example for,Hongnan structure belt,which is later for the shallow oil-gas to migrate,and mainly redistributed that the oil-gas has collected in middle Jurassic,and is secondary oil-gas pool.But,as for Shengbei structure belt,which is earlier for the shallow oil-gas to migrate,and is mainly the low-mature hydrocarbons of the Shuixigou Group coal seam to be captured.

四川省重点学科建设项目(SZD0414)

https://doi.org/10.11781/sysydz200704405