%0 Journal Article %A Yao, Jun %A Hu, Rongrong %A Wang, Chenchen %A Yang, Yongfei %D 2015 %I Begell House %K carbonate reservoir, digital rock, pore-scale network model, hybrid method, multiscale characteristics %N 1 %P 1-9 %R 10.1615/IntJMultCompEng.2014010500 %T MULTISCALE PORE STRUCTURE ANALYSIS IN CARBONATE ROCKS %U https://www.dl.begellhouse.com/journals/61fd1b191cf7e96f,3aa783e13c5ffcbe,3758fb6734760a2e.html %V 13 %X Carbonate reservoirs are inherently heterogeneous; the pore sizes can vary over orders of magnitude and often show trimodal distribution, and it is necessary to describe the pore characteristics of different scales in carbonate rocks. In this article, two-dimensional thin section carbonate images with different resolutions are collected with scanning electron microscopy; the lowest-resolution image shows vug characteristics, the intermediate resolution shows interpore characteristics, and the highest-resolution image shows intrapore characteristics. Based on three different resolution images, a Markov chain Monte Carlo method is used to reconstruct vug, interpore, and intrapore digital rock, and the corresponding pore-scale network models are extracted, respectively. Then, a hybrid method including superposition and integration is used to construct a carbonate multiscale network model. At last, the geometry-topology and flow properties are analyzed and compared among the vug, macro pore, micro pore, and multiscale networks. Results show that the carbonate multiscale network with hybrid method could capture the pore size distribution and connectivity characteristics of different scales simultaneously. More importantly, different contributions to flow properties of certain scale pore structures are recognized, flow processes are simulated among each pore-scale network under water wet conditions, and the water phase relative permeability curves of each pore network model have a similar tendency; however, the oil phase relative permeability curve of the multiscale network model has the highest isoperm saturation and lowest residual oil saturation. Compared with each single pore-scale network model, the multiscale network has a better connectivity and flow ability owing to the mutual connection between different scale pores, and it has important theoretical and applicational meanings for the microscopic flow study in carbonate rocks. %8 2015-01-29