Method for in situ recovery of liquid and gaseous products from oil shale deposits

摘要

A tunnel is formed above an in situ oil shale retort in a subterranean deposit containing oil shale. A void is excavated in the retort site and remaining deposit in the retort site is fragmented by explosively expanding toward the void to form a subterranean cavity containing a fragmented permeable mass of particles containing oil shale. The top of the fragmented mass is spaced downwardly from the tunnel to leave therebetween a pillar of unfragmented deposit. A retorting gas is introduced into the retort through a plurality of sloping passages from the tunnel for retorting oil shale in the fragmented mass. The liquid and gaseous products of such retorting are removed from the bottom of the retort. A portion of the carbonaceous products are used for generating electricity. In working a large area of deposit, a plurality of retorts are arranged in rows and columns. The tunnel is part of a tunnel system communicating with the tops of the retorts and having a peripheral double entry tunnel surrounding the rows and columns of retorts. Tunnel systems are also provided at a level adjacent the bottom of the retorts and at a level between the bottom and top.