Research on the Pore Evolution of Oil Shale under Different Thermal Treatment Temperatures Using NMR and FE-SEM Methods

Underground in situ pyrolysis for oil shale extraction is currently significant; the evolutions microstructure, porosity, and permeability parameters are essential factors evaluating productivity of after pyrolysis. With underground reservoir core, obtained from Jimsar Sag Junggar Basin China, as research object, samples were subjected to treatment at different high temperatures (400°C, 500°C, 600°C, 700°C). The NMR FE-SEM experiments on conducted; T 2 relaxation spectra, pore size distribution, porosity variation analyzed; relationships between movable fluid saturation established, respectively. results showed that when thermal temperature increased, rose continuously but laws. being lower than 400°C, increased slowly, growth rate rapidly was higher 500°C. In range 25°C~400°C, relatively slow. enhancing (500°C~600°C), accelerated rapidly. When continued rise (700°C), increase began slow down. There a nonlinear correlation an approximately linear saturation. findings 600°C suitable shale.