In situ hydrous pyrolysis/partial oxidation of organics at the site of the organics constrained in an subsurface reservoir produces surfactants that can form an oil/water emulsion that is effectively removed from an underground formation. The removal of the oil/water emulsions is particularly useful in several applications, e.g., soil contaminant remediation and enhanced oil recovery operations. A portion of the constrained organics react in heated reservoir water with injected steam containing dissolved oxygen gas at ambient reservoir conditions to produce such surfactants.

Disclosed is a method for removing phenols from an underground gasification zone by injecting an alkaline material to convert at least a portion of the phenols to the corresponding salt and producing the solution of said salt. Thereafter, the salt can be converted to the free phenol or merely evaporated to dryness. In both of these cases, the phenol or salt can be incinerated.

Disclosed is a process for recovering petroleum from subterranean, viscous asphaltic or bituminous petroleum-containing formations, including subterranean tar sand deposits. A zone of gas permeability is established in the formation first, such as by fracturing or gas sweeping a section of the formation. Oxidizing gas such as oxygen, air, oxygen enriched air, ozone, or chlorine, or a mixture of steam and an oxidizing gas is introduced into the zone of increased gas permeability to expand the zone and further to cause a reaction to occur between the oxidizing gas and the oxygen-susceptible groups or labile groups associated witn the bituminous or asphaltic petroleum molecules forming acidic or aldehyde groups. Next, a gaseous or liquid alkalinity agent such as ammonia is introduced into the formation to react with the oxidatively pre-treated groups in the bituminous or asphaltic petroleum to form surface active agents or surfactants in situ. Finally, steam or a mixture of steam and an alkalinity agent such as ammonia or steam and air or a mixture of steam, oxidative gas and an excess of ammonia is introduced into the treated zone to recover petroleum. This process may be applied as a push-pull process or it may be applied in a multi well, throughput process. In a preferred embodiment, gaseous ammonia serves as an alkaline agent to neutralize the surface active agents formed in the formation, and also functions as a non-condensable gas to prevent loss of gas permeability as the viscous petroleum is heated in the final stages of the process.

This specification is directed to a method of producing oil from an oil-containing subterranean formation by a caustic waterflood. Oil containing carboxylic acids is passed through an ion-exchange resin to selectively remove the carboxylic acids therefrom. The removed carboxylic acids are injected into the formation in conjunction with the caustic waterflood to enhance the production of oil from the formation.

A two-step method for recovering hydrocarbons from a subterranean formation in which in situ combustion is first initiated in the formation by injection of air, for example, through an injection well, the injection of air is terminated and in a final step a combustion-supporting gas such as air, air mixed with oxygen, etc. and a combustible gas such as hdyrogen, carbon monoxide and mixtures thereof are introduced into the formation preferably through separate sets of casing perforations and finally hydrocarbons are recovered via a production well.