Abstract: In-situ retorting methods include forming an in-situ mass of rubblized, hydrocarbon-containing minerals covering at least part of that mass with a nonflammable liquid such as water, uncovering part of the mass and retorting to produce hydrocarbon values from that part, and then progressively or sequentially uncovering other parts of the mass and retorting hydrocarbons from those parts. Methods for forming highly permeable rubblized masses include forming a retorting zone in a kerogen-bearing formation wherein two walls of the retorting zone form a low angle to one another, and cleaving oil shale from the upper wall beginning near the intersection of the two walls and proceeding upwardly.

Abstract: A process for the in-situ recovery of minerals from subsurface deposits comprises forming a gas-tight or self-sealing chamber and injecting into it a solvent which is pressure cycled over a predetermined period of time. This pressure cycling increases the mineral extraction efficiency by improving the dissolution of material contained in blind cracks in the underground formation.

Abstract: In a process for the recovery of resources from underground geological structures, the process is improved by fracturing the walls of the underground structure and large boulders or rocks by inducing thermal gradients in the deposits. Determination of the thermal gradients which will produce the desired fracturing pattern in each specific deposit involves subjecting a core sample to a controlled heating program. When the heating program has been established from tests on the core sample, it is then applied to the underground formation.

Abstract: A process for the in-situ recovery of hydrocarbon, carbon monoxide, and hydrogen values and associated minerals from subsurface oil shale deposits is provided by forming a gas-tight retort chamber and injecting it with a hot, pressurized gas followed by a solvent extraction and finally a combustion of the hydrocarbon residue. In order to conduct the process, the shale formation must be beneath a gas impermeable geological structure which will form a gas-tight chamber upon leaching of the water soluble minerals.

Abstract: A process for the in-situ recovery of hydrocarbon, carbon monoxide, and hydrogen values and associated minerals from subsurface oil shale deposits is provided by forming a gas-tight retort chamber and injecting it with various process gases which are pressure cycled over a predetermined period of time. This pressure cycling increases the extraction efficiency by improving the recovery of material contained in blind cracks in the underground formation, and by provising an independent means of controlling the thermal gradients induced in the deposit.