Two-phase model of thermal decomposition of shale stratum

Abstract

There are various methods of oil shale thermal processing with the purpose to generate primary energy product -so-called shale gas -however, methods that do not require the extraction of rock to the surface are of special interest [1]. In these methods, shale gas is extracted directly from the stratum as it is heating up, in one way or another.The aim of this work is to build a model of thermal decomposition of shale strata when they are heated by electromagnetic field.The model takes into account the phenomenon of thermal conductivity, interphase heat and mass transfer, thermal effect of chemical reactions and gas flow in the pores.Due to significant anisotropy of properties, shale stratum can be represented in the form of a solid porous plane, which has evenly distributed heat sources formed by electrodes, the distance between which L is much larger than their radii R 0 .The geometry of the computational domain is shown in Fig.

Composition of pyrolysis gas from oil shale at various stages of heating

“…The experimental data confirmed the estimates of the low rate of thermal energy distribution in an oil shale [5,6]. In this experiment, the temperature in the center of a heated zone at the time, when a temperature at 90 mm apart from the channel center did not reach 100°C, exceeded 900°C.…”

“…Heating the continuous medium, which takes place in a subterranean formation, a temperature gradient and the movement of liquid and gaseous products of pyrolysis are unavoidable. Calculation of such heating requires taking into account many factors [5].…”