Studies On Origins And Migration Direction Of Petroleum In Shaya Uplift Of Tarim Basin

Beginning with basic geology data, such as the structural evolution, depositional feature, source rock condition, field (reservoir) distribution and trap types in Shaya uplift and areas nearby, the comprehensive research of oil and gas formation, key reservoir formation stage, marine and continental hydrocarbon migration direction in Shaya uplift has taken in this study. According to the extensive hydrocarbon geochemical characteristic analysis, the index of dividing marine and continental hydrocarbon formation was defined. The Shaya uplift has the characteristic of "two sources and two direction of hydrocarbon provision, convergency placed marine and continental hydrocarbon ". The main source rocks were Triassic-Jurassic continental source rock in northern Kuqa depression and Cambrian-Ordovician marine source rock in southeastern Mangar depression, and it is confirmed that the Cambrian-Ordovician marine source rock in shaya uplift is obviously different from east to the west; continental hydrocarbon in northern Kuqa depression could be divided into:lacustrine argillaceous rock and coal. The research of marine and continental hydrocarbon migration direction shows that the marine hydrocarbon mainly migrated from southeast to the northwest along the Ordovician unconformity surface and large scale faulting, and accumulated in Ordovician carst reservoirs. In Carboniferous and its upper layers were secondary oil reservoirs which mainly migrated along faults. The main source rocks of continental hydrocarbon were coal in Yangxia sag and lacustrine source rock in Baicheng sag. Continental hydrocarbon migrated laterally from north to the south, the Yaha-Dalaoba area has mixing sources of lacustrine rock coal.