Evolutionary Law and Geological Significance of Migration and Superposition of Underwater Distributary Channels in the Bashijiqike Formation,Yaha Area,Tarim Basin
In order to clarify the migration characteristics of the underwater distributary channel at the front of the seasonal braided river delta under the arid climatic conditions in the Yaha Area Tarim Basin,the contact relation-ship and migration evolutionary characteristics of the underwater distributary channel were discussed on the basis of the core observation,thin-section identification,grain-size analysis,and logging curve analysis in conjunction with the sedimentary background by taking the Bashijiqike Formation as an example.The results show that the Bashijiqike Formation in the study area is a front subfacies of the braided river delta,where the microfacies such as underwater distributary channel,mouth bar and interdistributary bay are developed;the width of the underwater distributary channel ranges from 200 to 1 500 m,the sand-to-ground ratio of the sediments is high,and the chan-nel is migrated frequently,and the migration and superposition styles are of interdistributary bay separated,spliced and cut type;the physical properties of the sand body of the underwater distributary channel are better in general,and the sand body can be formed into continuous favorable reservoirs with good pore permeability after migration and superposition.It is of great significance to clarify the migration and superposition law of the underwater distributary channel for further oil and gas exploration in the Yaha Area.
channel contact relationshipchannel migration and superposition characteristicsBashijiqike Forma-tionYaha AreaTarim Basin
万方数据
维普
