Abstract: The process of the present invention involves the following steps:producing, as by hydrofracing, a substantially horizontal fracture in the subterranean rock mass to be processed;emplacing an explosive charge in the mass in spaced juxtaposed position to the fracture;enlarging the fracture to create a void space thereat, an initial lifting of the overburden, and to provide a free face juxtaposed to and arranged to cooperate with the emplaced explosive charge; andexploding the charge against the free face for fragmenting the rock and to distribute the space, thus providing fractured, pervious, rubble-ized rock in an enclosed subterranean chamber.Firing of the charge provides a further lifting of the overburden, an enlargement of the chamber and a larger void space to distribute throughout the rubble-ized rock within the chamber.

Abstract: The subterranean fragmented and pervious zone is formed beneath an overburden which, as a first step of the process, is lifted as a substantially monolithic land mass to produce a void space and a free space proximate the rock to be fragmented, the raised overburden thus providing a substantially impervious lid or closure for the fragmented zone as formed by the present invention. Explosive charges are then placed proximate to and for blasting against the free face formed on raising the overburden. The charges are exploded to fragment the rock to distribute the space, thus producing fractured, pervious rubble-ized rock in a defined and enclosed zone. Different techniques are disclosed for the critical raising of the overburden and subsequent fragmenting of the rock.

Abstract: Subterranean carbonaceous deposits, such as oil shale or the like, that are located at or close to the surface, are prepared for retorting by drilling blast holes from the surface into the deposit, and blasting, creating a rubble pile that reaches the surface. The surface is sealed by suitable means, and the oil shale is retorted in place. Where a stratum of barren rock lies between the carbonaceous deposit and the surface, the blast holes are drilled and blasted in such a manner as to maximize the fragmentation of the carbonaceous deposit, and minimize the fragmentation of the overlying barren stratum. Where overburden conditions are not suitable for treatment by this method, the overburden is removed by strip mining methods, and the carbonaceous deposits are exposed for treatment by the method described above.

Abstract: Subterranean mineral deposits, such as oil shale or the like, are prepared for in-situ retorting by selectively mining out an area at the base of the deposit leaving an overlying deposit supported in a suitable manner such as by a plurality of pillars. The overlying deposit is expanded in any suitable manner into the underlying area in a fashion to create a predetermined distribution of permeability from an area of low permeability to an area of high permeability. An inlet is provided at the low permeability area and an outlet at the high permeability area. A suitable medium is introduced into the deposit at the low permeability end for extracting and forcing mineral values from the deposit toward the outlet end for recovery.

Abstract: Subterranean mineral deposits, such as oil shale or the like, are prepared for in situ retorting by selectively mining out an area at the base of the deposit leaving an overlying deposit supported in a suitable manner such as by a plurality of pillars. The overlying deposit is expanded in any suitable manner into the underlying area in a fashion to create a predetermined distribution of permeability from an area of low permeability to an area of high permeability. An inlet is provided at the low permeability area and an outlet at the high permeability area. A suitable medium is introduced into the deposit at the low permeability end for extracting and forcing mineral values from the deposit toward the outlet end for recovery. .Iadd.