不同温度作用下油页岩内部孔隙结构精细表征

Advanced characterization of pores in oil shale at different temperatures

利用显微CT试验分析系统和压汞仪,对取自抚顺西露天矿的油页岩试样经过高温作用热解后的孔隙结构进行度量表征,得出:(1)300～600℃温度段是抚顺油页岩内部有机质热解的主要阶段;(2)在显微CT能分辨的孔隙尺度(>1.94μm)范围内,油页岩的孔隙不发育;在压汞法测定的孔隙尺度(7nm～1.94μm)范围内,油页岩的孔隙较为发育。高温作用后,油页岩内部的有机质不断发生热解,各孔径阶段的孔隙不断形成,孔隙结构也在发生变化,各孔径阶段的孔隙逐渐连通,超大孔(>1.94μm)和中孔(0.1～1μm)的孔隙率逐渐增大,小孔(0.01～0.1μm)和微孔(<0.01μm)的孔隙率也基本处于增大的状态,为油气物质的产出提供通道。

The oil shale samples from Fushun west open-pit mine were pyrolyzed at high temperature.The pore structure of the samples was characterized by a micro-CT experimental system and mercury injection apparatus.The results show that 300-600℃are the main stage of organic matter pyrolysis inside Fushun oil shale;the pores of the oil shale are not developed in the range of the pore size(>1.94μm)that can be resolved by the micro-CT.The pores of the oil shale are more developed in the range of pore size(7 nm-1 mm)measured by the mercury injection method.After the effect of high temperature,the organic matter in the oil shale is continuously pyrolyzed,pores in each aperture are constantly formed,the pore structure is constantly changed,pores connected gradually.The porosity of super large pores(>1.94μm)and middle hole(0.01-0.1μm)increased gradually,the porosity of small holes(0.01-0.1μm)and micropore(<0.01μm)are also in an increasing state basically,which provide a channel for hydrocarbon substances.