Title

Characteristics of strike-slip fault belt and its hydrocarbon geological significance in the eastern area of central Tarim Basin

单位

(1.西北大学地质学系,大陆动力学国家重点实验室,陕西西安710069;2.中国石油化工股份有限公司华北油气分公司采油气工程服务中心,陕西咸阳712000;3.中国石油化工股份有限公司西北油田分公司勘探开发研究院,新疆乌鲁木齐830011)

Organization

(1.State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China;2.Hydrocarbon Production Engineering Service Center,Sinopec North China E&P Company,Xianyang 712000,China;3.Research Institute of Exploration & Production,Sinopec Northwest Company,Urumqi 830011,China)

摘要

塔中东部断裂带发育北北东(NNE)、北东东(NEE)和北西西(NWW)向3组直立走滑断裂,断穿了寒武系—石炭系地层,具有明显上拱或下弯地震反射特征。三维地震资料精细解释发现,断裂带地层上拱下弯与断裂带厚度和两侧厚度差异之间存在一定的相关性,据此可以判断断裂古应力场性质。断裂带地层的下弯与张扭活动有关,与断裂带地层厚度的同生增大相对应;断裂带地层的上拱则与压扭活动有关,与断裂带地层厚度的同生减薄相对应。据此得出三组走滑断裂的活动期:NNE向断裂形成于晚奥陶世桑塔木组沉积期,经历了左行压扭—左行张扭—静止—张扭4个阶段;NEE和NWW向断裂均以共轭张扭性质开始于中寒武世,NWW向断裂在中寒武世以后停止活动,NEE向断裂则在良里塔格组沉积期停止活动。3组走滑断裂对奥陶系蓬莱坝组、鹰山组及一间房组碳酸盐岩中广泛分布热液岩溶储层的形成及油气聚集都有控制作用。

Abstract

Three sets of vertical strike-slip faults trending NNE,NEE and NWW exist in the eastern area of central Tarim Basin.They cut the strata from Cambrian to Carboniferous.Up-warp or down-warp reflection phenomenon along fault belts exists in 3D seismic profiles.Detailed 3D seismic interpretation shows that the up-warp or down-warp variation is related to the difference in thickness between the fault belt and its bilateral sides.The down-warp phenomenon in fault belt corresponds to the thickness increasing of strata in fault belt and it is considered as a result from the fault tenso-shear activities.The up-warp in fault belt corresponds to the thickness decreasing of the stratum in fault belt and it is generated from fault compresso-shear activities.Therefore,three active periods of the faults have been concluded.NNE trending fault develops in late Ordovician Sangtamu formation deposition period,and goes through four stages,from left-lateral compresso-shear activities to left-lateral tenso-shear activities,then static and finally tenso-shear activities.NEE and NWW trending faults which were conjugated tenso-shear develops in Middle Cambrian,and the later one stops activity after the Middle Cambrian,however,the former one keeps tenso-shear property until the late Ordovician Lianglitage formation.In this region,hydrothermal karsts reservoir are widely distributed in carbonate rocks of Ordovician Penglaiba formation,Yingshan formation and Yijianfang formation.The three sets strike-slip faults take an important role in the generation of karst reservoir formation and hydrocarbon accumulation.

关键词：

塔中东部; 走滑断裂; 上拱下弯; 活动期次; 岩溶;

Keywords:

the eastern area of central Tarim Basin,; strike-slip fault,; up-warp and down-warp,; active stages,; karst;

基金项目

国家自然科学基金项目(41390451)和中国石油化工股份有限公司西北油田分公司项目(KY2013-S-033)联合资助。

DOI

10.3969/j.issn.1000-1441.2016.06.009

塔中东部走滑断裂带特征及油气地质意义