PRELIMINARY INVESTIGATION ON THE FORMATION MECHANISM OF SILURIAN RESERVOIR IN TAZHONG LOW—UPLIFT OF TARIM BASIN

Tazhong low-uplift is an early Paleozoic remnant paleo-uplift,which was formed during the late Caledonian period on the background of the sedimentary uplift developed during the early Caledonian period.The Silurian asphalt sandstones extensive in the area were formed in the process of petroleum migrationand accumulation rather than after reservoir formation.The entrapment of hydrocarbons by the Siluriansandstones experienced a complicated process of accumulation,destruction and reaccumulation.Thefavourable petroleum accumulation area in the Silurian considered as target bed is the plunging part innorthwestern Tazhong low-uplift.