Study On Methods Of Rock Physical Modeling And Physical Parameter Prediction For Shale Oil And Gas Reservoirs

As a typical unconventional oil and gas reservoir,shale oil and gas exploration and development have received much attention in recent years.Compared with conventional oil and gas reservoirs,shale reservoirs have the characteristics of low porosity and permeability,complex pore space and mineral composition,and strong anisotropy,which greatly increases the difficulty of identifying shale oil and gas reservoirs.At present,research in China mainly focuses on enrichment conditions,reservoir formation models,and geological evaluation.There is relatively little research on the prediction of rock physics and physical parameters of shale oil and gas reservoirs,and it is necessary to explore the relationship between rock properties and geophysical observations.The physical parameters such as porosity,clay content,and kerogen content are of great significance for the identification and evaluation of shale oil and gas reservoirs.The formation of shale oil and gas reservoirs in China is complex.Currently,there is very little research on rock physics experiments of shale samples in the seismic frequency range in China,and the rock physics response is not clear.This article conducts ultrasonic and low-frequency experiments on shale rock samples taken from the Changning block in the Sichuan Basin,measures and analyzes the relationship between elastic and physical properties of rocks,as well as the anisotropic characteristics of rocks.Based on the experimental test results,a physical model of shale oil and gas reservoirs with frequency variation is constructed based on the complex composition and strong anisotropy of shale minerals,and its dispersion and attenuation phenomena are analyzed,And compare the predicted results of the model with the experimental results to verify the applicability of the model.Based on the established shale reservoir frequency dependent rock physics model,develop frequency dependent rock physics template technology to analyze the quantitative relationship between reservoir elastic parameters and physical properties parameters.Finally,combined with the rock physics model,the MCMC inversion method is used to invert the physical parameters of the reservoir such as porosity,clay content,and kerogen content,providing a basis for subsequent seismic prediction and reservoir evaluation.