Digital Characterization Of Pores And Fractures And Calculation Of Physical Properties In Typical Marine Black Shale

Digital core is a new numerical simulation method.It is a three-dimensional(3D)visual model based on two-dimensional(2D)core image.It can be saved permanently,easily called and reused,and can solves effectively the deficiencies of traditional rock physics experiment.Shale oil and gas are the hotspot in the field of international petroleum industry.The shale core is dense,its pore and fracture are small,its poroperm is very low.Thus,the shale property test and simulation are difficult to be realized.Using of digital core to carry out shale property test and simulation have advantages of efficient and lower cost.In this paper,a series of calculation and simulation programs were developed based on MATLAB platform by using typical marine black shale cores.A series of works including the microscopic characteristics analysis of typical marine shale,core CT scanning and pretreatment,shale 3D digital core reconstruction,shale static parameter calculation,and shale capillary pressure curve simulation are carried out,the main results and awareness are obtained as following.i Carried out a typical marine black shale microscopic characteristics analysis.Based on the previous research works,three shale coring wells data are analyzed,and the typical marine black shale microscopic characteristics are revealed as many pore types,complex pore structure,tight poroperm,etc.It is difficult to use the physical simulation experiment,however,it is beneficial to digital core research.? Completed a typical marine black shale core CT scan.According to the characteristics of shale,the suitable microstructure test method and the processing flow is designed.About 400 2D shale microstructure images are obtained by scanning.A computer software is designed to filter and segment 2D images,and verify the reliability of the 2D images.? Reconstruct 3D shale digital core.The software is designed to read 2D images segmented completely,establish 3D data cubes,refine and smooth data cubes,develop and display 3D shale digital core using volume rendering method,and verify the reliability of the 3D shale digital core finally.iv Calculation of shale static parameters.Based on the 3D shale digital core,the lattice Bolzmann method is used to simulate the porosity,tortuosity and absolute permeability and so on.A new algorithm is used to calculate shale specific surface,and the software is designed to complete abovementioned works verify their reliability.v Simulate the capillary pressure curve of the shale.Based on the biphasic incompatible fluid lattice Bolzmann method,the oil and water is chosen as fluid,and the software is designed to simulate the oil-water distribution in the shale under different pressures,and the oil-water capillary pressure curve in shale core is calculated completely.Through the above works,the 3D shale digital core is established by using a series of procedures,four physical parameters about shale core are calculated,and the 3D digital characterization and static parameters of typical marine shale are successfully completed,which provide the methodological basis and technical support for deep research of shale digital core.