库车前陆盆地古隆起及双超压体系对天然气成藏的控制作用  

Controlling effects of palaeouplifts and dual overpressure systems on gas accumulation in the Kuqa foreland basin

作　　者：孙冬胜 金之钧[1] 吕修祥[2] 杨明慧[2] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中国石油大学,北京102249

出　　处：《石油与天然气地质》2007年第6期821-827,855,共8页Oil & Gas Geology

基　　金：国家"十五"科技攻关项目(2001BA605-02-03-04)

摘　　要：通过地层接触关系、沉积特征及地震反射特征等,在库车前陆盆地识别出6个燕山期古隆起及1个古近纪末的低幅度背斜构造。认为燕山末期的古隆起控油,古近纪末期的低幅度构造聚气,新近纪末期的冲断背斜圈闭富气,说明前陆盆地的古隆起与克拉通盆地的古隆起对油气分布具有同样的控制作用。划分出库车前陆盆地纵向上2个超压体系,认为深部超压体系的形成与快速埋藏条件下的大量生烃有关,而上部超压体系是后期构造侧向挤压的结果。古隆起聚集了大量早期生成的天然气,在形成深部超压体系的同时,也决定了新近纪冲断背斜发育的位置,进而也决定了现今天然气藏的分布。Six palaeouplifts of the Yanshan period and one anticline of low amplitude at the end of the Paleogene were identified in the Kuqa foreland basin according to strata contact relations, sedimentary characteristics, and seismic reflectance signatures. This paper concludes that the palaeouplifts at the end of the Yanshan period con- trolled oil accumulation, the anticline of low amplitude at the end of the Paleogene controlled gas accumulation, and the thrust anticline trap at the end of the Neogene was rich of gas. The conclusion suggests that palaeouplifts of foreland basin had a similar controlling effect on hydrocarbon distribution as that of palaeouplifts in eraton basin. Two vertical overpressure systems were identified in the Kuqa foreland basin. The deep overpressure system was caused by the generation of a large amount of hydrocarbons under conditions of fast burial, while the shallow overpressure system was the result of a late lateral tectonic compression. A large amount of earlier-generated gas were accumulated in the palaeouplifts, leading to the formation of the deep overpressure systems. The palaeouplifts determined the location of the Neogene thrust anticline and thus the distribution of present gas reservoirs.

关 键 词：古隆起 双超压体系 构造挤压 成藏序列 天然气 库车前陆盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]