Abstract The percolation probabilities of the actual oil shale sample of the size of 0.82 mm×7mm at different temperatures were calculated according to the data from the three-dimensional micro-CT using the three- dimensional percolation theory for porous media. The values of the percolation probability reflected the distribution of the largest groups of connected pores and the degree of the connectivity of the porous media, which avoided the influence of the smaller pore group on the judging of the permeability of porous media. When the temperature was in the ranges of 300 ℃ to 400 ℃ and the porosity of the oil shale was 8%–12%,the percolation probability increased quickly. The largest group of pores connected completely the two ends of up and down of the three-dimensional rock core. The percolation transition occurred with the percolation threshold value in the range of 8%–12 % for the oil shale. The percolation of the fluid was found to be difficult when the porosity was smaller than 8%. When the porosity was larger than 12%,pore connectivity was good for output and input of the oil gas.
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Received: 05 May 2014
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