3D Reconstruction Of Porous Medium Based On Rock Slice Image

Rock slice images can be analyzed through the computer technology, so as to extract rock sample parameters rapidly and exactly, such as porosity, pore shape, pore ratio and other feature information. Based on the feature information of two-dimensional rock images, it can be extended to the three-dimensional space for the simulation of porous media structure. On this basis, three-dimensional reconstruction models are combined with microscopic seepage simulation for the follow-up study.In this paper, three dimensional reconstruction of porous medium is based on rock slice images. The casting slice images, used as experimental materials, are obtained under the optical microscope, which is different from the CT scanning of rock cores. First, the threshold segmentation of image is processed to get the skeleton and pore binary figure which is used in the three dimensional reconstruction. Then through the digital image processing to analyze the color spaces of rock slice image, the Cr channel of YCbCr space is used for the threshold segmentation. The result of image is treated with morphology processing, a good training image with the pore geometry structure is obtained finally.Based on the binary image, multiple-point geostatistics is applied to the image training and three dimensional reconstruction, and SNESIM (single normal equation simulation) method is mainly used for the reconstruction of digital cores in this paper. To test the feasibility and reliability of the algorithm, the cores from the wells of Su279and Lian47from Changqing oilfield are selected for the reconstruction. The experimental results show a good trend of aperture distributions between the reconstructed digital core and the real value, and the relative errors of porosity are within8%. Thus, the above research content indicates that the three-dimensional reconstruction of rock slice image is effective.