The Evaluation Methodology In Seismic Prediction For "Sweet Spots" Of Dense Carbonate Rocks

In recent years,with the adjustment of the energy-resource structure and the development of oil and gas exploration,unconventional oil and gas resources have gradually entered people's field of vision.This paper focus on unconventional dense carbonate reservoir,and usually we consider the dense carbonate rocks have the characteristic of low porosity,low permeability,strong anisotropic characteristics.the applicability of the ordinary physical model rock and reservoir prediction method poor.In order to solve the problem of reservoir prediction of dense carbonate rocks,this paper mainly predicts the "sweet spots" of dense carbonate reservoirs on the basis of rock physics technology.According to the particularity of dense carbonate rocks,seismic rock physics model are improved from three aspects,i.e,solid component,fluid composition and aperture structure.So we get an anisotropic rock physics model for dense carbonate reservoirs based on pore connectivity theory.Besides,we systematically studied the pore type a new theoretical model,pore connectivity,pore structure and pore fluid effects of four factors on the rock physics modeling.The results show that the pore volume,pore connectivity and pore types of mudstone have a great influence on tight carbonate rocks,and the results can be confirmed by the validation of the actual logging data.Furthermore,the new fluid identification factors,based on the anisotropic model above,are compared with convention fluid factors in both oil-bearing reservoir and non-reservoir interval and good effect was obtained.