The Tectonic Characteristics And Its Control On The Oil And Gas Accumulation In The Lenghu Tectoniczone Of The North Margin Of The Qaidam Basin

The Lenghu tectoniczone which located in northwest northern margin of the Qaidam basin, rich in hydrocarbon resources, but its complex tectonic increased difficulty on hydrocarbon exploration in the region.study the structure and its controlaction on oil and gas accumulation deeply would not only be conductive to the deployment of hydrocarbon exploration in the study area but also hydrocarbon exploration of the whole northern margin of the Qaidam basin.In this paper, the auther studied the structural feature, the causes of structure and the controlling on reservoir formation of structure mainly. First, through the analysis of basic structure in the study area, the author summarized structure distribution regularities and tectonic style type. The author think that the most folds were anticline, the most faults were reverse faults and the overall structural units were distributed by "anti-S-type" in the plane; structural styles can be divided into three types pattern which include compressional structure, strike-slip tectonics, extensional tectonics. Then, through the analysis of stratigraphic contact, fault cutting relations and the formative period of main structures, the auther think that there being six angular unconformity, a parallel unconformity in the study area, and the main structure trace were essentially formed in the Cenozoic.Then with the help of five chief profile evolution plot drawed by the auther himself and the analysis of tectonic stress orientation of different stages, the auther further analyzed the possible structure causes of every era, and build a three-dimensional geological model of the study area by the FLAC3D software, while a numerical simulation of tectonic origin was made. Finally, through the analysis of the relationship between structure along with its evolution and reservoir, the auther believe that the development and distribution of the Jurassic source rocks were controlled by structure, the structural trapping reservoirs were dominated, the important hydrocarbon migration passage are faults.At the same time, with the control of structures hydrocarbon migration to lateral migration dominated the early and late vertical migration significantly.