Abstract:
A method for recovering heavy oil or bitumen from an underground reservoir by injection of anhydrous ammonia gas at a temperature greater than the temperature of the reservoir and a pressure such that the ammonia gas fills voids left by recovered oil and condenses to liquid as the gas cools from contact with the reservoir. The ammonia reacts with native naphthenic acids in the oil to form surfactants. These surfactants emulsify the oil into the immiscible liquid ammonia, which flows into a producing well that carries the emulsified fluid to the surface. The fluid may be depressurized to release the oil and recover the ammonia as a gas that may be recycled. The process requires no water supply, no water treatment, no water disposal, less heat than generating steam, and is compatible with oil-wet, acid-soluble, carbonate-type formations.
Abstract:
A thermal phase separation simulator and method for testing chemicals is disclosed. The simulator comprises a circular block heater carousel (lO)mounted for rotation on a stage (20). The carousel includes a circular array of test wells (12) for receiving a plurality of test bottles (60), a plurality of heating elements (14) and thermocouples (15) disposed between the wells. Each well has an illumination port (40) and a vertical slit (24) to the outside to allow visual observation or imaging of a vertical swatch of the bottle. An illumination source (41) aligns with the illumination port of each well in response to rotation of the carousel. The method includes adding a mixed phase fluid to a plurality of bottles, adding a chemical agent to each bottle, and simulating a thermal phase separation. Images of the fluid in each bottle are captured and analyzed to determine the performance of the one or more chemical agents.
Abstract:
Air and ammonia gas are introduced into a subterranean formation during the in-situ combustion to increase the mobility of hydrocarbons in a subterranean formation and facilitate recovery of the hydrocarbons from the subterranean formation. The air supports in-situ combustion of a portion of the hydrocarbon within the subterranean formation to form water and establish a combustion front. The ammonia gas contacts the hydrocarbons ahead of the combustion front and reacts in-situ with naphthenic acid in the hydrocarbon to form a surfactant. The hydrocarbons, water and surfactant then form an oil-in-water emulsion that drains more freely through the formation. A production well, in fluid communication with the hydrocarbons ahead of the combustion front, may be used to remove the oil-in-water emulsion from the subterranean formation.