Fine Depiction of the South China Sea Paleogene Reservoir from Prestack Geostatistical Inversion

In consideration of the problems of deep burial of reservoirs,complex geological background and low resolution of seismic data,poor data quality in Paleogene Reservoirs of Pearl River Mouth Basin in the South China Sea,the uncertainty in structural interpretation and low accuracy of reservoir prediction were induced and it was difficult for interpretation.In order to elaborate description of reservoir,first in consideration of the target zones,a petrophysical forward model was established,by reconstructing the density of development wells and acoustic logging curves,the rock physical property was analyzed,and rock physical template was established for providing theoretical basis for prestack inversion.Secondly,the pre-stack time migration gather was re-processed and divided into five superimposed gathers of near,middle and far distances,based on fine horizon calibration,reasonable inversion parameters were chosen for carrying out AVA prestack sparse spike inversion(CSSI),therefore the lithologic and stratigraphic interpretation was improved,reservoir characterization accuracy was enhanced,and them based on rock physical template,the reservoir space distribution was predicted.In order to meet the accuracy of finer description of sand and mud thin interbeds in the target zones and on the basis of pre-stack sparse spike inversion(CSSI),AVA geo-statistical inversion techniques are used to obtain multiple bodies for high precision reservoir inversion,from which the structural,geologic and reservoir parameters suitable for inversion are chosen for establishing the geological model with high resolution,it is used for fine description of deep reservoirs,determining reserves,for the optimization of oilfield development plan and adjustment of well locations.