The Space Relationships Between Sources And Reservoirs And The Process Of Gas Forming Relevant To Unconformity In The Paleozoic Of Ordos Basin

This thesis is about the unconformity between upper and lower Paleozoic in the Ordos Basin. Researches focus on the location of the largest driving force area of the hydrocarbon source rock related the unconformity between upper and lower Paleozoic, the condition of transport and block of gas in the unconformity.Analysis of the distribution of natural gas reservoirs in unconformity based on drilling and logging date.Preliminary analysis the feature of the accumulation process of natural gas reservoirs.The results of this research indicates the following:1. The location of the largest driving force area of the hydrocarbon source rock of upper Paleozoic is defined in the different periods of Ordos Basin. The location of the largest driving force area of Lower Cretaceous is Maerzhuang-Dabazui-Duhoutan-Jiyuan-Majiashan in the period of settling of Ordos Basin. The location of the largest driving force area of Lower Cretaceous is Tiansh-uibao-Huanxian and Tekesumiao in the period of elevation of Ordos Basin. The location of the largest driving force area of nowadays is the south of Tieke-sumiao in Ordos Basin.2. The rocks below the unconformity between upper and lower Paleozoic, which plays the part of sealing better for gas when migrating in the unconformity, develops plaster rock surround Mizhi area in the eastern of Ordos Basin. In the other areas of the basin, cracks and the limestone developed in the dissolution porosity are good passages for the transport of gas.3. In the reservoirs related the unconformity between upper and lower Paleozoic in the Ordos Basin, these reservoirs are mainly distributed in the west of the area where plaster rock developed.and the supply of gas was controlled by the location of the largest driving force area, the accumulating of gas was controlled by rocks block condition.