Gas accumulation model of Ordovician in the north section of the western margin of the Ordos Basin
In order to boost the efficient exploration of natural gas,this paper studies the geological conditions of Ordovician gas accumulation in the north section of the western Or-dos Basin.The basic geological characteristics such as geologic structure and sedimentary evolution are revealed.Based on the data of reservoir characteristics and geochemical testing of source rocks,the geological conditions of Ordovician gas accumulation are sorted out.Ac-cording to the spatial distribution of source rock,reservoir and cap rock,the corresponding natural gas accumulation model is proposed.The Ordovician source rocks are mainly argilla-ceous rocks,and dolomite,limestone and shale can be regarded as reservoirs.Natural gas accumulation modes can be divided into,model of self-generated and self-stored within the source in the deep-sea plain shale,model of self-generation and self-storage within the source of the continental slope turbidite limestone,model of upper-generation and lower-storage near the source in the carbonate platform limestone and model of upper-generation and lower-storage far from the source in the carbonate platform dolomite.According to the drilling data,the model of self-generated and self-stored within the source in the deep-sea plain shale is the main gas accumulation mode in the study area,which is the key target of the following natural gas exploration.
western Ordos BasinOrdoviciannatural gas reservoirgas accumulation model
万方数据
维普
