Study On Fluid Identification Method Of Pore Reservoir

With the development of oil and gas geophysics,the identification of underground fluids has always been the focus and core of research.And the accuracy of exploration has also put forward higher requirements than before.In order to more accurately characterize subsurface reservoirs and identify fluids contained in reservoirs,we can no longer rely solely on previous equivalent medium theory to characterize reservoirs and identify fluids,but instead use pores that are more in line with actual formation conditions.The media theory describes the reservoir and extracts fluid-related parameters from it to accurately identify the fluid in the reservoir.Reflection seismic data contains many important and abundant information for seismic fluid identification.How to extract the fluid information contained in the reflection seismic data for fluid identification is a problem we need to study.for this problem.Based on the theoretical study of porous media,we deduced the classical Hooke’s law,the shear stress of fluids,and the conservation of momentum and mass of plane waves.It is possible to decouple some of the parameters during the asymptotic analysis and discard high-order terms.Then the relationship between the asymptotic equation and the porous media is obtained through the solid-liquid and fluid-phase petrophysical properties of the porous media.Finally,an asymptotic expression of the reflection and transmission coefficients of the plane wave normal incidence in the seismic frequency band is obtained.Based on this asymptotic expression,a pore reservoir fluid identification factor was established.Through the optimization of the asymptotic equation,the inversion objective function containing the fluid factor is established.Then the fluid factor contained in the objective function is inversely calculated by the least squares inversion algorithm based on the generalized S-transformation,thereby establishing the porosity.Reservoir fluid factor inversion method.The greater the value of the fluid factor,the greater the probability that the fluid is present in the reservoir.This method is applied to the inversion of actual seismic data in a deepwater area of ??the South China Sea.From the inversion results,it can be observed that the fluid identification factor in the area where the hydrocarbon reservoir is located is high or high,and the inversion result is measured.The well data agree well with each other,and the fluid distributionrange and plane distribution characteristics of the reservoir can be determined.It is proved that the reservoir fluid factor obtained by this method can perform more accurate gas detection of the reservoir.Improve the ability of seismic reservoir fluids to detect and predict the accuracy of results.