Investigating The Rock Pore Structure Characteristics By Using The Technique Of Oblique Incidence Reflectivity Difference Imagining

The microscopic pore structure of reservoir rocks includes the size,geometry,distribution and connectivity of pores and throats,which is characterized by diversity,heterogeneity and complexity.Different pore structure characteristics of reservoir rock have important influence on physical properties of rock such as porosity,permeability,storage,distribution and migration of oil,gas and water in reservoir.Therefore,accurately,qualitatively and quantitatively describing pore micro structure is the basis for evaluating and predicting reservoir productivity.With the utilization of oil and gas resources and the development of characterization technology,characterization of rock pores is developing towards the direction of high-precision nondestructive testing,multi-means joint characterization and three-dimensional imaging.As an ellipsometry,obliqued incident reflectivity difference(OIRD)has the characteristics of high resolution,high sensitivity and non-contact.Some applications have been developed in the fields of biology,medicine,thin film growth and oil and gas detection fields.In this paper,OIRD technique is used to characterize and evaluate rock pores.We optimize and improve traditional OIRD systems in combination with microscopic imaging techniques.The main research results are as follows :1.The response of OIRD signals to different mineral components is determined by OIRD fixed-point test,linear scanning and two-dimensional scanning imaging combined with the simulation results of OIRD physical model.OIRD 2D imaging can clearly and accurately characterize the size,shape,distribution and composition of different substances in rocks.OIRD results are consistent with SEM and EDX results,which proves that the dielectric sensitivity of OIRD can be used to distinguish and characterize different minerals in rocks.2.OIRD 2D images of rubber simulated pores,volcanic rocks and sandstone are obtained by mechanical scanning OIRD system,and three-dimensional images are obtained by fitting the two-dimensional images of continuous layers.The influence of different sample pore areas on OIRD signal is clarified.OIRD 2D and 3D imaging results were used to analyze and evaluate the characteristics of pore size,three-dimensional shape,distribution and rock porosity development.3.OIRD 2D and 3D imaging of oil shale containing banded organic matter and flocculent organic matter is carried out.According to the different responses of OIRD signal to rock pores,fractures and mineral components,pore and fracture part and organic matter part in OIRD imaging map are distinguished and extracted,and 3D characterization of rock macro pore structure and components is realized at the same time.4.The micro-imaging OIRD system is independently designed and built,which solves the problem of blurred pore edge when the mechanical scanning OIRD system images micro and nano pores,and solves the problem of imaging resolution limited by the accuracy of displacement platform and spot size.Through image processing methods such as image enhancement,noise reduction,RGB component separation and pixel value extraction,improve the imaging quality.