Reservoir Prediction Research Based On Pre-stack Simultaneous Inversion

For complex litho-logic reservoirs,pre-stack inversion takes advantage of pre-stack gathers information,so more elastic physical parameters can be used for the identification of lithology and fluid.And pre-stack inversion is more accurate than post-stack inversion.For the exploration of complex litho-logic reservoirs provides an effective means.This study area is located in Sulige gasfield.The target layer He 8 belongs to a typical litho-logic gas reservoir.The sedimentary system is braided river delta sedimentary system.Rivers change frequently and it makes the sedimentary microfacies in phrase space superimposed each other.So thesis put the He 8 layer of sand-shale reservoir as research object,and use pre-stack simultaneous inversion to do reservoirs prediction.The main thesis task as follows:(1)In view of the cost of field data acquisition is too high,we rarely do shear wave logging.Several shear wave prediction methods are compared simultaneously to determine the suitable way that meets the requirement of pre-stack inversion.Thesis chooses 6 different methods to do the shear wave prediction and the Krief method is the best method.(2)To calculate the rock physical parameters making use of logging information and predicted shear wave logging data and find the suitable parameters by histogram,crossplot and for pre-stack inversion.(3)The AVO forward modeling for target layer has been done.And the paper has analysised if the target layer has AVO response characteristics.(4)The thesis has done the inversion process of well tying,establishment of low-frequency model,divided the angle gather.Then the workflow of pre-stack inversion is fulfilled to predicate the gas reservoir.The Jason software is used to finish pre-stack simultaneous inversion for He 8 of Sulige gasfield.By way of analysising connecting-well section of rock physical parameters the results shown that poisson ratio,?_R and?/?are the best qualified parameters and the pre-stack simultaneous inversion is a suitable method for reservoir prediction.