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| STUDY OF PYROLYSIS AND INTERNAL STRUCTURAL VARIATION OF OIL SHALE BASED ON 3D CT IMAGES |
| ZHAO Jing，FENG Zengchao，YANG Dong，KANG Zhiqin |
| (Institute of Mining Technology，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China) |
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Abstract A micro-CT experimental system was used to scan a specimen of oil shale subjected to pyrolysis at different temperatures. From 3D CT images based on X-ray attenuation coefficients，the evolution of pores and cracks in the specimen was analyzed at different stages of pyrolysis. The results show that：(1) From 20 ℃ to 600 ℃，the specimen is transformed from a compact state to a porous medium. (2) At the higher temperatures，increasing numbers of voids become interconnected. At 100 ℃，the voids are restricted to a very small region；but as the temperature is raised to 200 ℃，channels for oil and gas seepage are formed within the study region. At 600 ℃，the pyrolysis rate of the specimen is calculated to reach 39.80%；and the largest void is 97.45% of all the voids. All voids are interconnected into one large void，forming a channel for the seepage of oil and gas running through the entire X-rayed region. The study conclusions are of great significance for discovering how the channels for oil and gas seepage developing during in-situ pyrolysis of oil shale.
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Received: 01 March 2013
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2014, Vol. 33 
