塔里木盆地周缘凹陷带含油气特征及勘探前景

在塔里木盆地周缘发育有8个中、新生代的凹陷,即北部的阳霞、拜城、乌什凹陷,西南的喀什、叶城凹陷,东南的民丰和若羌凹陷,以及东部的英吉苏凹陷。在东部、北部、西南部的5个凹陷中已发现油气田。周缘凹陷带发育以侏罗系为主体的烃源岩、以碎屑岩为主体的多套储盖组合以及多种成因类型的构造圈闭。从已发现油气分布特点看,主要受生烃中心、深大断裂以及构造带等因素控制。以晚期成藏为主的周缘凹陷带具有巨大的勘探潜力,特别是勘探程度很低、尚未获得突破的乌什凹陷及塔东南凹陷带也是不容忽视的勘探领域。

Oil and Gas Characteristics and Exploration Prospect for Sags on Periphery of Tarim Basin

A total of eight Mesozoic and Cenozoic sags developed on the periphery of Tarim basin-Yangxia, Baicheng and Wushen on the northem border, Keshen and Yecheng in the southwestem border, Minfeng and Ruoqiang on the southeastern border as well as Yingjisu in the eastem border. Oil and gas fields have been found in the five sags on the eastem, northem and southwestem borders. In the peripheral sag belts developed Jurassic hydrocarbon source rock, a number of reservoir-caprock assemblage dominated by clastic rocks and structural traps of different genesis types. Based on the characteristics of discovered oil and gas distribution, those sags are controlled by such factors as hydrocarbon source center, deep and large faults and structural belts. The peripheral sags with reservoirs formed in the late stage have great potential for exploration. Wushen sag and the sag belt in the southeastern part of Tarim basin in particular are the exploration areas that should not be neglected for their low exploration degree. Breakthroughs are to be made in those areas.