In situ reverse combustion

Analyses of Oil Produced during in Situ Reverse Combustion of a Utah Tar Sand... 

The in situ combustion method of enhanced oil recovery through air injection (28,273,274) is a chemically complex process. There are three types of in situ combustion dry, reverse, and wet. In the first, air injection results in ignition of cmde oil and continued air injection moves the combustion front toward production wells. Temperatures can reach 300—650°C. Ahead of the combustion front is a 90—180°C steam 2one, the temperature of which depends on pressure in the oil reservoir. Zones of hot water, hydrocarbon gases, and finally oil propagate ahead of the steam 2one to the production well. 

Late in 1975, personnel from Laramie Energy Research Center (LERC), then of the U.S. Energy Research and Development Administration, conducted an in situ recovery experiment in the Northwest Asphalt Ridge deposit near Vernal, Utah. Reverse combustion was chosen as a recovery method because it was felt that this method was more likely to succeed for in situ recovery of tar sands hydrocarbons. 

This section outlines the methods available for the in situ gasification of coal. In terms of the combustion process itself, both forward and reverse combustion are employed. Forward combustion is defined as movement of the combustion front in the same direction as the injected air whereas... 

The ChemChar process is a patented, ex situ method for the treatment of hazardous and mixed wastes using reverse-burn gasification. Organic components of the treated waste are converted to a combustible gas and a dry, inert solid. The solid can be mixed with cement to prevent leaching of radioactive or heavy-metal constituents retained in the char residue after gasification, or the solid can be further reduced by forward-bum gasification. 

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