渤海西部沙垒田凸起区走滑断层演化及其对油气的控制作用  

Evolution of strike-slip faults in the Shaleitian bulge of the western Bohai offshore and their control on hydrocarbons

作　　者：彭文绪[1,2] 张志强 姜利群 石文龙 陈国童 

机构地区：[1]同济大学海洋与地球科学学院,上海200092 [2]中海油渤海油田勘探开发研究院,天津300452

出　　处：《石油学报》2012年第2期204-212,共9页Acta Petrolei Sinica

基　　金：国家重大科技专项"近海大中型油气田形成条件及勘探技术"(2008ZX05023)资助

摘　　要：渤海海域西部沙垒田凸起区潜山为太古界花岗岩,新近系河流相碎屑岩直接覆盖在基底潜山之上。该区发育长约20km的NE向右旋走滑断层,斜切整个凸起。潜山内发育的NE和NW向两组走滑断层走向夹角约100°,NE向主走滑断层持续活动至今;NW向断层延续较短,局部表现为沟道,新近纪停止活动。该区走滑断层整体表现为负花状构造。新近纪构造运动在主走滑断层附近诱发大量近EW向左旋张扭性小断层并对主走滑断层形成切割。高分辨率三维地震资料精细解释表明,该区断层演化经历了三个阶段,即新近纪前基底断裂走滑阶段、新近纪早期盖层张性断裂弱雁列化阶段、新近纪晚期盖层张扭性断裂强雁列化阶段。凸起区走滑断层的多期活动不仅形成了断背斜圈闭,而且控制了走滑断层两盘古近系的沉积,对油气聚集和重新分配产生影响。Buried hills in the Shaleitian bulge of the western Bohai offshore are composed of Archaeozoic granite,which is immediately covered by Neogene fluvial clasolites.In this area there is a well-developed NE dextral strike-slip fault that stretches for about 20km and slantingly cuts through the whole Shaleitian bulge.The angle between the NE and NW strike-slip faults within the buried hills is about 100°.The major NE strike-slip fault keeps unceasingly active,while NW faults being no longer active in Neogene extend discontinuously with partial segments displayed as channels.Strike-slip faults in this area commonly show a minus flower structure and the Neogene tectonic movement induced numerous approximately-EW dextral extensional minor faults near the major strike-slip fault,which cut the major strike-slip fault occasionally.Based on detailed interpretations of high-resolution seismic data,we divided the evolution of faults in this area into three stages： the formation of base strike-slip faults in pre-Neogene,the formation of feebly-en-echelon faults in cover strata in early Neogene and the formation of tenso-shear and strongly-en-echelon faults in cover strata in late Neogene.Multiperiodic activities of strike-slip faults in the uplifted area not only formed faulted-anticline traps but also controlled Paleogene deposits on both sides of the faults,exerting an influence on the accumulation and redistribution of hydrocarbons.

关 键 词：走滑断层 花状构造 沙垒田凸起 渤海湾盆地 

分 类 号：TE111.2[石油与天然气工程—油气勘探]