从压(扭)性垂向交叉断裂对柴达木盆地七一沟深层含油气预测

AN ASSESSMENT OF HYDROCARBON-BEARING FEATURE IN DEEP STRUCTURE IN QIYIGOU REGION,QAIDAM BASIN,FROM THE FORMATION OF COMPRESSIVE(-SHEAR),VERTICAL INTERSECTING FAULTS

昆仑山以北柴达木等区的压(扭)性(平面上)垂向交叉(剖面上)断裂是由北西西向挤压断隆、断陷相间带与北东东和北北西两组左、右行共轭扭压隆、坳相间带交接,并与北北东向张(扭)性断裂配套,在来自南南西印度洋壳应力场作用下所形成的构造格局。它不仅控制了盆地的形成及盆地内各级构造单元,也控制了盆地内油气的形成与聚集,进而形成新的选坳(凹)定带的找油观点。本文是对该新观点的实践检验,并已初见成效。

Under a SSW directed stress field generated by the stress acting by In- dian ocean crust,a planar compresso-shear and vertically intersecting(in pro- file) faulting action formed a NWW oriented zone with alternate compressive fault-uplifts and fault-depressions joining two in echelon sets of NEE and NNW conjugate torsional-compressional zones with alternate uplifts and de- pressions,as well as NNE oriented torsional-tensile faults.This structural framework dominates the area of Qaidam basin and other places north of Kunlun mountain.It controls the formation of the basin and the structural units of different orders within the basin,and the generation and accumula- tion of hydrocarbon as well.On the basis of the facts mentioned above,a new view point of selecting depressions and belts that favour to the forma- tion of oil and gas field has been put forward and will be illustrated by the examples in this paper.