中文摘要：

基于高精度显微CT技术，采用多孔介质三维逾渗理论，计算不同温度下油页岩试件（φ0.82 mm×7 mm）真实三维数字 CT岩芯的逾渗概率。逾渗概率的大小实质上反映多孔介质内部最大连通孔隙团的分布程度，可对多孔介质的连通性进行直观、准确地判定，避免因为统计对渗透性无贡献的“小级别死端孔隙”而造成对多孔介质渗透性优劣的误判。当温度达到300℃～400℃，油页岩孔隙率为8%～12%时，逾渗概率开始快速增长，最大孔隙团已完全连通三维数字CT岩芯的上、下两端，证明油页岩内部发生逾渗转变，逾渗阈值应处于8%～12%范围内。研究表明：随着温度的上升，当油页岩孔隙率低于8%时，孔隙连通团的连通性很差，相互隔离，导致流体难于渗透；而当孔隙率高于12%时，孔隙连通团的连通性很好，渗流通道变得十分通畅，更易于油气的产出和高温流体的注入。该较低的逾渗阈值范围大大降低了油页岩开发、利用的难度，为实现大规模油页岩原位注热开发提供有力的技术支撑。

英文摘要：

The percolation probabilities of the actual oil shale sample of the size of φ0.82 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.