Sinistral strike slip of the Zhangjiakou-Penglai Fault and its control on hydrocarbon accumulation in the northeast of Shaleitian Bulge, Bohai Bay Basin, East China

Abstract

Abstract The structural style, fault activity, strike-slip displacement, and the formation mechanism and hydrocarbon migration and accumulation in the center tectonic zone in the northeast Shaleitian Bulge of Zhangjiakou-Penglai Fault Zone were studied by seismic attribute analysis, structural geometric analysis, fault activity analysis, structure evolution history and simulation of hydrocarbon migration, based on 3-D seismic and drilling data. The main results are as follows: (1) The study area is a superimposed tectonic zone, which experienced early (Paleocene and Eocene) extension and late (Oligocene and Pliocene-Quaternary) strike-slip and pull-apart. (2) The sinistral strike slip of the northeast Shaleitian Bulge of Zhangjiakou-Penglai Fault Zone went through two periods, Oligocene and Pliocene-Quaternary, and the Bohai section was active earlier than the inland section. (3) The sinistral strike slip displacement of Zhangjiakou-Penglai Fault is 4 km since Cenozoic, including 1 km in the Oligocene, and 3 km in the Pliocene-Quaternary. (4) The strike-slip movements have resulted in the increase of fault activity and basin-mountain restructure in the fault zone, also contributed to the formation of the central tectonic belt and the conjugate evolution in north-east structural belt. (5) The conjugate strike slip of the Zhangjiakou-Penglai Fault Zone dominated the migration and accumulation of hydrocarbon in shallow formations by controlling the injection points and segments of hydrocarbon from the deep layers to shallow layers.