Seismic Reservoir Prediction In The Ng Formation Of NP 2-1 Oilfield

NP2-1 is an anticline structural reservoir complicated by faults in Nanpu No.2structure.Braided river sedimentary sand bodies are developed in the upper part of the Ng formation.The sand bodies are complexly distributed and the oil-bearing area is small and fragmented.The current resolution of seismic data in the area is not ideal,the previous reservoir prediction effect is poor,the sand body structure is unclear,and it is difficult to effectively and reasonably interpret the oil-water relationship,resulting in unclear distribution of remaining oil in the area and low degree of control and utilization.This study is based on the theory of seismic reservoir prediction,comprehensively applies well logging and seismic data,and uses seismic attribute analysis and seismic inversion to carry out reservoir sand body prediction in the upper part of the Ng formation,and studies the spatial distribution law of sand bodies.The oilfield formulates development plans and the deployment of injection-production well patterns to provide geological support.According to the research content of this thesis,based on the previous geological and drilling research,the forward simulation of seismic response was first carried out.Based on the scale of the braided river sand body in the upper part of the study area,a sand body forward model was made,and different velocities and density parameters were set for different lithology bodies based on the rock physics analysis of the reservoir.The following forward simulation analysis results show that seismic excited at the main frequency of 20 Hz ? 30 Hz can effectively distinguish the distribution changes of sand bodies with a thickness of 10-20 meters.The stratified slice method is used to extract amplitude-type seismic attributes,analyze the geophysical significance of various attributes,and compare with the above-ground data to select multiple attributes such as the root-mean-square amplitude for prediction of sand body distribution.By analyzing the physical properties of the reservoir rocks in the study area,a wave impedance curve capable of effectively responding to changes in the lithology of the reservoir was prepared,and a geological statistical inversion tool was used to perform seismic inversion of wave impedance.By analyzing the correlation between the wave impedance and the mud content,the wave impedance distribution is used as a trend to simulate the mud content distribution,and the variation function is adjusted to obtain the ideal inversion result.Furthermore,a three-dimensional model of lithology distribution in the reservoir is established by using the wave impedance attribute body association simulation.Combined with seismic attribute analysis and geostatistical inversion,the sand body distribution in the upper section of the study area is predicted.