Inversion And Application Of Porosity And Pore Structure Based On Rock Physical Model

In the study of oil and gas geophysics,Porosity is an important parameter to describe the reservoir.The pore structure is the main factor affecting the elastic properties of the rock.They are very important for reservoir prediction.The definition of pore structure is not uniform at present,and researchers often define the pore structure from their own research needs.In this paper,according to the needs of the study,the definition of pore structure includes pore shape,size and pore connectivity.In the current seismic porosity inversion,the pore structure parameters are not included.In this paper,based on the unified model of rock skeleton,the inversion formula of porosity and the calculation formula of pore structure parameters are established.In the case of different geological and rock pores,the unified model of rock skeleton can adjust the parameters of pore structure,and we can obtain different expressions of rock skeleton model.Therefore,based on the unified model of rock matrix,the pore structure and pore structure are taken into account in order to improve the adaptability to geological conditions.And the inversion method is more flexible and more comprehensive.In this paper,based on the unified model of rock skeleton,the inversion formula of porosity is established.And the effects of porosity and pore structure on the elastic properties of rock are studied.As a result,under certain conditions,the influence of pore structure on the elastic properties of rock is equal or even more important than that of porosity.In this paper,based on the commonly used rock physics model simulation analysis,the results show that the parameters of rock structure increases when porosity increases;and the parameters of rock structure increases when consolidation coefficient became larger;and the parameters of rock structure decreases when pore aspect ratio became larger.In this paper,we use the seismic data and logging data in X area through the unified model of rock skeleton to inverse the seismic porosity and pore structure parameters.The inversion results of single well show that the inversion porosity are close to the measured porosity and the deviation is small,and it is proved that the method is reliable and effective.In the reservoir,it reflecting the reservoir space is fracture pore and rock compaction degree is strong that the pore aspect ratio between 0.1 to 0.25,and the coefficient of consolidation between 2 to 5.The inversion results of seismic show that the porosity is between 0.1 to 0.25,and the parameters of pore structure is between 0.02 to 0.04.The inversion results coincide with the actual situation.