Evolution Law of Porosity and Permeability in In-Situ Pyrolysis Zone of Oil Shale

Abstract

This paper tested the permeability and porosity of oil shale during the pyrolysis process. Combined with the in-situ pyrolysis simulation, this paper analyzed and discussed the evolution of permeability and porosity in the oil shale in-situ pyrolysis zone through electric heating technology. During the pyrolysis of oil shale, the porosity and permeability increased significantly when temperature ranged from 300℃ to 500℃. The scope of the in-situ pyrolysis zone expanded with the increase of heating time and pyrolysis saturation was reached essentially after six years of heating. After in-situ pyrolysis, oil shale's permeability and porosity changed greatly within 7.5 meters in the vertical direction and 4.8 meters in the horizontal direction from the central wellbore of the heating well. Oil shale in this area changed from aquifuge to aquitard.