Research On Source Reservoir Capping Formation And Their Complex Of The Jurassic In The QiangTang Basin

The characteristics of sedimentary facies and oil and gas reservoir of Jurassic in QiangTang basin. On the basis of determining the sedimentary facies style,the sedimentary development characteristic and distribution of time and space, the model of oil and gas reservoir is build up through analyzing the relationships between depositional environment and oil and gas reservoir characteristics. It supplies theoretical base and practical data for the oil and gas exploration of the research area.There have a veritey of sedimentary facies styles of Jurassic in QiangTang basin,it not only develops alluvial fan,fan delta,delta and lagoon,standing for the border of the basin,but also develops deep basin,deep lagoon and flysch,standing for the center of the basin. It developes frontal uplift on the center uplift,and peculiar sedimentary facies on its both side, carbonatite glacis,shallows,delta,marine evaporate,providing abundant datas for researching the structure and pala-eogeographic of the basin.Abundant of research data show that the majority source rock is mixed source rock in Qiangtang basin.,â…¡kerabitumen occupy a dominate position, the type of organic material of carbonatite source rock is superior to argillaceous source rock's. Boglime and limestone is the major type ofâ…¡1 kerabitumen.Clasolite and carbonatite are the major reservoir, in north of basin, carbonatite is the major reservoir, and in east of the basin, the major reservoir is clasolite, the majority carbonatite are dolomite rock and ooidal limestone, the majority clasolite are silt rock and fine sandstone.According to the research data of surface and core, we make research in character of enclosed rocks, the development in longitudinal of the cap rock, the area in horizontal which develops cap rock, and the validity of the cap rock.Based on the source,reservoir and cap rock allocation of time and space in the layer profile of Mesozoic in qiangtang basin.Through multidisciplinary analysis, it is thought Nadigangri-Donghu-Bandaohu and Biruocuo-Tumen are the best prospective oil-gas zone.