Abstract: An improved tertiary recovery method for obtaining medium and high gravity crude oil from subsurface formations is disclosed wherein the gravity of the crude oil is downgraded. An in-situ combustion method is used where the boiling temperature of a light viscous crude is altered to provide residual coke, enabling sustained combustion.

Abstract: A method of recovering oil from a subterranean, viscous oil-containing formation comprising injecting into the formation an aqueous solution of at least one salt of carbonic acid, and then recovering the oil from the formation by means of a drive means.

Abstract: The present invention relates to a process for the recovery of mineral values from ores containing such wherein at least part of the mineral values is present as a refractory mineral complex. A fluid bed reactor is utilized to simultaneously solubilize the mineral values not present as the refractory complex and to separate the refractory complex from the ore.

Abstract: Recovery of oil from an oil-containing formation is effected by injection of steam followed by a soak period, if desired, and then injecting a mixture of sodium bicarbonate and citric acid that react in the formation to form carbon dioxide in situ. A driving fluid, preferably hot water or low quality steam (less than 20%), is then injected to displace the carbon dioxide and oil toward a production well for recovery. The process may be operated under conditions wherein the carbon dioxide formed in situ is miscible with the formation oil at the pressure and temperature of the formation thereby effecting miscible displacement and enhancing oil recovery.

Abstract: A method for recovering hydrocarbons from oil bearing shale which comprises placing the shale in pulverized form into a retort and simultaneously processing under retorting conditions.