Abstract: A method for heat injection into a subterranean diatomite formation is provided. The method utilizes a heater that is placed directly in the diatomite formation without cement around the heater. Diatomite is very soft, and will quickly fill in around the heater, operation of the heater will sinter the diatomite and significantly increase the original thermal conductivity and strength of the diatomite.

Abstract: A method for heat injection into a subterranean diatomite formation is provided. A heater is placed in a wellbore within the diatomite formation, and the heater is then operated at a temperature above that which the heater could be operated at long term in order to better sinter the formation in the vicinity of the wellbore. The improved sintering of the diatomite significantly improves the heat transfer coefficient of the diatomite and thereby increases the rate at which heat can be injected from a constant limited long term heater temperature.

Abstract: A process of recovering oil from a subterranean reservoir in which the oil is acidic but forms monovalent cation soaps of only relatively low interfacial activity when reacted with aqueous alkaline solutions, comprises displacing the oil toward a production location with a mixture of gas and cosurfactant-containing aqueous alkaline solution.