库车坳陷北带逆掩断层在天然气运聚成藏中的作用  

The effects of overthrusts on gas migration and accumulation in the north belt of Kuche depression

作　　者：付晓飞[1] 吕延防[1] 付广[1] 杨晶霞[2] 

机构地区：[1]大庆石油学院勘探系 [2]大庆油田公司采油一厂

出　　处：《中国海上油气（工程）》2004年第3期161-165,共5页China Offshore Oil and Gas

基　　金：国家 973攻关项目"高效大气田形成机理及分布研究"( 2 0 0 1CB2 0 914 )资助成果

摘　　要：库车坳陷北带逆掩断层按其与构造层的关系可划分为穿盐断层、盐下断层、盐上断层和盐内滑脱断层等 4类 ,其中穿盐断层、盐下断层和盐内滑脱断层对主要目的层天然气运聚成藏的影响较大。断层与烃源岩和盖层的切割关系不同 ,其在天然气运聚成藏中的作用不同 ,因此断层组合模式是影响该地区天然气运聚成藏的关键因素。逆掩断层主要活动期与烃源岩生排气高峰期的匹配关系 ,决定了该地区天然气的主要成藏期为库车末期—西域期。构造挤压而形成的储层异常高压与天然气的主要成藏期一致 ,以及成藏期后穿盐断裂的垂向封闭 ,使得该地区许多圈闭中的天然气与异常高压共存并保存至今。In the north belt of Kuche depression, overthrusts can be divided into four types in terms of their structure relationships, i.e. through_salt, sub_salt, supra_salt and intra_salt slipping overthrusts. The through_salt, sub_salt and intra_salt slipping overthrusts have greater effects on gas migration and accumulation in the main targets. Different cutting relationships of overthrusts with source rocks and seals may result in different effects on gas migration and accumulation, and the overthrust combination pattern is a key factor in formation of gas reservoirs in this area. The match of main overthrust activity with peak gas generation and expulsion from source rocks has led to a main period of gas accumulation from the latest Kuche to Xiyu. Abnormal high pressure in reservoirs caused by tectonic compression is coincident with the main period of gas accumulation, and the through_salt overthrusts formed after the main period have provided vertical seals. All these have resulted in coexistence of gas and high pressure and its preservation up to now in many traps.

关 键 词：天然气 成藏原因 库车坳陷 逆掩断层 油气运移 油气聚集 

分 类 号：P618.13[天文地球—矿床学]