ANALYSIS OF TRANSIENT TEMPERATURE DISTRIBUTION EXTERIOR TO AN IN SITU OIL SHALE RETORT.

The initial-boundary-value problem for the transient temperature fields in oil shale, which is heated by a propagating combustion flame in an in situ retort chimney, is formulated and solved analytically. The transient temperature fields in the oil shale surrounding the retort are calculated and discussed with respect to their spatial variations and dependence on the flame relaxation time. The theoretical temperature distributions are shown to be consistent with those observed experimentally. The high temperature core extends less than a retort radius into the surrounding shale bed. This result has implications for the in situ retort design and the environmental impact of in situ retorts.