塔里木盆地柯坪断隆构造特征及油气勘探潜力

Tectonic characteristics and hydrocarbon exploration potential of Keping fault-uplift in Tarim Basin

基于非地震资料的认识和一系列二维地震剖面的精细解释,剖析了柯坪断隆的构造属性、构造演化和断裂系统,划分了内部构造单元。研究认为:柯坪断隆为塔里木盆地的一部分,是盆地的一级构造单元;受不同断裂控制,柯坪断隆可分为3个构造分区,即东段阿克苏区、中段柯坪区和西段西克尔区,分别发育不同的构造样式;柯坪断隆经历了加里东期、海西期、印支期—燕山期、喜马拉雅期等多期构造运动,最终形成了现今的隆-坳格局。油气地质条件综合分析表明,柯坪断隆发育优质烃源岩、良好的生-储-盖组合和古隆起背景,沙井子构造带志留系天然气圈闭资源量达0.2018×10^(12)m^(3),柯坪断隆震旦系—寒武系深层石油资源量为16.84×10^(8)t,油气勘探潜力巨大。其中,阿克苏区的古生界、新生界构造-岩性圈闭,以及柯坪区和西克尔区的寒武系盐下隐伏构造是主要的油气勘探目标。

Based on the understanding of non-seismic data and the fine interpretation of a series of two-dimensional seismic profiles,the paper analyzes the tectonic attributes,tectonic evolution,and fault system of Keping fault-uplift,and divides the internal tectonic units.The study shows that Keping fault-uplift is a part of Tarim Basin and a first-order tectonic unit of the basin.Controlled by different faults,Keping fault-uplift can be divided into three tectonic zones,i.e.,Aksu area in the eastern section,Keping area in the middle area,and Xikeer area in the western section,of which the tectonic styles are different.Keping fault-uplift underwent several tectonic movements,including Caledonian,Hercynian,Indosinian-Yanshanian,and Himalayan movements,finally forming the current uplift-depression pattern.The comprehensive analysis of petroleum geological conditions shows that Keping fault-uplift has high-quality source rocks,good source-reservoir-cap assemblage and paleo-uplift background,the amount of natural resources from Silurian gas trap in Shajingzi structural belt is 0.2018×10^(12)m^(3),and the amount of deep oil resources in Sinian and Cambrian reservoirs of Keping fault-uplift is 16.84×10^(8) t.Those indicate a great potential for oil-gas exploration.In the study area,the Paleozoic and Cenozoic tectonic-lithologic traps in Aksu area as well as the Cambrian subsalt concealed structures in Keping and Xikeer areas are the main hydrocarbon exploration targets.