Multi-scale and multi-region pore structure analysis on sandy conglomerate whole core with digital rock model

Abstract

Based on industrial CT, the whole core sandy conglomerate is scanned with a resolution of 0.5 mm/voxel, and the representative debris region and filling region subsample is selected to be scanned with a resolution of 15 µm/voxel using micro-CT. Then, four regions of the whole core sandy conglomerate image are segmented with the multi-threshold segmentation algorithm including macro-pore, debris, filling and gravel regions, while binary segmentation is performed on the debris and filling subsamples to segment the debris pores and filling pores respectively. Finally, the multi-scale and multi-region pore network model of the sandy conglomerate was constructed by the integration method to analyze the different types of pore characteristics. It can be found that, the integrated sandy conglomerate model can reflect the structural characteristics of macro-pore, debris pore and filling pore at the same time. Meanwhile, the porosity/permeability of integrated sandy conglomerate model are calculated and is basically consistent with the that of lab test results, which greatly increases the accuracy of the multi-scale multi-region pore network model.