Lithological Trap Identification And Reservoir Prediction Of The Cretaceous Bottom Filling Body In The Northern Yanmuxi Area

The Yanmuxi area is located on the western arc-shaped structure belt as a region with great potential for exploration where found Shenquan,Shengnan and Yanmuxi oil fields and Dadun oil structure.The study area is located in the northern part of Yanmuxi area where the sedimentary filling body is developed.It is difficult to obtain a reliable conclusion due to the lack of well control.Aiming at the difficulty of no-well control,it is necessary to make a fine structure interpretation for the bottom of the Cretaceous,identify the depositional filling body as well the reservoir prediction of the Cretaceous bottom based on the 3-D seismic data of Yanmuxi area.At first,the sequence stratigraphic framework of the target layer is established by the fine calibration,and it is prior to make it clear that the structural morphology and fracture characteristics in the northern part of the study area.In order to solve the problem of the uncertainty of lithology in the filling body,it is clear that the body is filled with sediments in the medium-silt sandstone as well a small amount of mudstone which in a several underwater distributary channels.The conclusion is obtained through establishing different source and lithologic forward modeling combined and compared with the actual seismic data reflection characteristics as with the sedimentary facies.We analyze the logging response of underground reservoirs,conduct the reservoir prediction for the target layer by inversion and seismic attributes extraction,predict the vertical and horizontal stacking relationship and the distribution law of the sand bodies in the filling body and clarify the development of the river sand bodies.Finally,we put forward a favorable drilling wells development program through plenty of factors just as structural characteristics,reservoir development as well by the analysis of the reservoir formation conditions,oil&gas migration laws and hydrocarbon detection technology.By the time,a set of practical and feasible forecasting method for the region to find no-well control lithologic reservoirs has been summed up.The method takes macro geological guidance and micro fine characterization as the core.