新疆博格达山北缘大龙口地区构造特征与油气勘探前景  

Structural Features and Petroleum Exploration Prospective in Dalongkou Area of the Northern Bogda Mountain,Xinjiang

作　　者：孙自明[1] 

机构地区：[1]中国石化石油勘探开发研究院,北京100083

出　　处：《现代地质》2015年第1期45-53,共9页Geoscience

基　　金：中国石油化工股份有限公司科技开发项目"西部山前构造带构造建模与有利区带评价"(P07015)

摘　　要：大龙口地区位于新疆博格达山与准噶尔盆地的结合部位,属于博格达山北缘山前冲断带的组成部分,关于该区地下地质构造特征,长期以来缺乏清楚的认识。通过地表地质、地震和非地震资料的综合研究,纵向上以阜康逆冲断裂为界,将该区划分为下盘伸展构造系统和上盘逆冲推覆构造系统,前者为原地系统,构造变形较弱,保留有早二叠世裂谷的隆坳结构,对重新认识博格达山地区早二叠世的区域大地构造背景及演化具有重要意义;后者构造变形强烈,总体以自南向北的冲断推覆为主,并伴有一定的走滑扭动变形。经过多期构造运动,阜康断裂上盘勘探目的层已裸露,加之褶皱和断裂发育,油气保存条件差,勘探前景较差;而断裂下盘发育早二叠世残留凹陷,圈闭发育,油气保存条件好,勘探前景较好。Dalongkou area,located between Bogda Mountain and the eastern Junggar Basin,Xinjiang,is an in-tegral part of the northern fold and thrust belt of Bogda Mountain.Many studies have been carried out about the surface structural features in recent years,but the underground structural features are not clear till now due to the complex structural deformation and poor seismic imaging quality making identification of underground struc-tures difficult.By surface geology,seismic and magnetotelluric data integrated research,given Fukang thrust fault works as a detachment,two structural systems can be divided vertically which are the extensional tectonic system of the Early Permian rift in the lower part and the fold and thrust system in the upper part.The former belongs to the in situ system with weak structural deformation,and the juxtaposed tectonic framework of the Lower Permian faulted high with fault depression is clear which is of great importance in rethinking regional tec-tonic setting and evolution of Bogda Mountain in the Early Permian;the latter,with intense structural deforma-tion,is characterized by the thrusting from south to north,and accompanied by some strike-slip deformation. Undergoing multiple-stage tectonic movements,the Permian to Jurassic exploratory objectives are exposed, together with the intense deformation of folds and faults,and the preservation becomes poor,herein makes pe-troleum exploration prospects poor.On the other hand,there exist favorable petroleum elements,and given the existence of an Early Permian “residual fault depression”,a greater exploration potential for oil and gas can be assumed in the footwall of the Fukang thrust fault.

关 键 词：构造特征 伸展构造 逆冲推覆构造 油气前景 大龙口地区 博格达山北缘 新疆 

分 类 号：TE121.2[石油与天然气工程—油气勘探]