Abstract: A method for in situ recovery of oil from oil shale containing oil bearing compound. The method begins with thermally decomposing the kerogen underground to produce oil vapors, combustible gases, and carbon residue, followed by conducting the oil vapors and combustible gases to aboveground and recovering it there. Next comes the steps of burning the carbon residue underground at a controlled rate such that the temperature of the formation remains below the softening temperature of the spent shale and at controlled oxidation so that carbon monoxide is produced and of conducting the carbon monoxide to aboveground and recovering it. After the burning step has been completed comes the steps of injecting water in the form of liquid, vapor, mist or steam into the hot formation to produce steam at high temperature, and conducting the high temperature steam aboveground and recovering it there.

Abstract: A process for obtaining useful products from an oil shale formation that has intermixed nahcolite and dawsonite. An aqueous solution of sodium hydroxide, containing a surfactant, is injected into the formation via wells. The sodium hydroxide reacts with the nahcolite to yield a sodium carbonate solution, which is withdrawn for further processing. Thereafter the shale is retorted in situ, with controlled pyrolysis while supplying air in controlled amounts, and petroleum products are recovered. Then water is sent into the retorted formation to produce steam, which is recovered. At some stage before or after the retorting, the dawsonite is reacted with NaOH and recovered as sodium aluminate in solution, which may be hydrolyzed or carbonated above ground to precipitate hydrated alumina. Carbon dioxide may be added to the recovered sodium carbonate aboveground to precipitate sodium bicarbonate, which may be heated to form solid sodium carbonate.