Abstract: A composition for closing pores in a formation following a steam-flooding enhanced oil recovery process. The composition comprises an aqueous temperature activated gellable mixture. This mixture is comprised of water, water dispersible polymers, phenolic compounds, and aldehyde producing compounds. Polymers which can be utilized herein include polyvinyl alcohol, polyacrylamide and poly(acrylamide-co-acrylamido-2-methylpropane sulfonate). Phenol is the phenolic compound of choice. At a formation temperature greater than 300.degree. F., trioxane, the preferred aldehyde producing compound decomposes to yield formaldehyde which reacts with phenol to form phenolic resin in situ. The resin gels the polymer and forms a solid gel in a heated zone of the formation.

Abstract: A method for minimizing well recompletions in a multiple zone hydrocarbonaceous fluid containing formation. A steam flooding enhanced oil recovery (EOR) is conducted in the upper zone of said formation via fluidly communicating injector and producer wells which penetrate the upper and lower zones. The wells are unperforated and do not communicate with each other in the lower zone. Thereafter, a temperature activated gellable composition is injected into the upper zone where it forms a solid gel. Afterwards, both wells are perforated so as to fluidly communicate with each other in the lower productive interval. Subsequently, a steam-flooding EOR operation is conducted in the lower level and hydrocarbonaceous fluids are removed therefrom. Polymers utilized in the gellable composition include polyvinyl alcohol and polyacrylamide cross-linked with phenol and an aldehyde producing compound sufficient to form a phenolic resin in situ.

Abstract: A composition for closing pores in a formation following a steam-flooding enhanced oil recovery process. The composition comprises an aqueous temperature activated gellable mixture. This mixture is comprised of water, water dispersible polymers, phenolic compounds, and aldehyde producing compounds. Polymers which can be utilized herein include polyvinyl alcohol, polyacrylamide and poly(acrylamide-coacrylamido-2-methylpropane sulfonate). Phenol is the phenolic compound of choice. At a formation temperature greater than 300.degree. F., trioxane, the preferred aldehyde producing compound decomposes to yield formaldehyde which reacts with phenol to form phenolic resin in situ. The resin gels the polymer and forms a solid gel in a heated zone of the formation.

Abstract: A process for minimizing well recompletions in a hydrocarbonaceous fluid containing formation having an upper productive interval temperature in excess of 300.degree. F. In this process, a temperature activated gellable composition is injected into a producer well in the productive interval after cooling said well to a temperature of about 300.degree. F. to about 450.degree. F. Once in the productive interval, the formation heats the gellable composition to a temperature sufficient to cause the composition to form a solid gel thus closing pores in the upper productive interval. Thereafter, ungelled composition is either diluted or removed from cooler areas of the formation so as to prevent forming a solid gel therein. Afterwards, a steam-flooding or a steam stimulation oil recovery operation is conducted to remove hydrocarbonaceous fluids from a lower productive interval without recompleting said lower interval.

Abstract: A process for closing pores in a heated steam swept zone of a formation having zones of varying permeabilities where a temperature activated aqueous gellable mixture is utilized following a steam flooding or steam stimulation enhanced oil recovery method. After being placed into the steam swept zone having varying permeabilities, a temperature above 300.degree. F. activates components in the gellable mixture which causes a solid gel to form which closes pores in the steam swept zone. A spacer volume of cold water is pumped into the formation to remove any ungelled mixture. Steam is directed into an unswept zone and hydrocarbonaceous fluids recovered therefrom. Polymers utilized include polyvinyl alcohol and polyacrylamide cross-linked with phenol and an aldehyde producing compound sufficient to form a phenolic resin in situ.

Abstract: High permeable thermally fluid swept zones in an oil containing formation are selectively plugged by a high temperature selective gel-forming solution without plugging the less permeable unswept portion of the formation. Ungelled solution in the less permeable unswept portion of the formation in the vicinity of the injection well is removed and a thermal fluid is injected into the formation that sweeps oil from the less permeable, unswept portion of the formation, thereby resulting in more complete displacement of oil from the formation.

Abstract: A miscible flooding process for oil recovery employs a multiple contact miscible solvent such as carbon dioxide and an additive such as butane which lowers the minimum miscibility pressure of the oil/solvent system. The additive is injected in a slug with a solvent, preferably followed by a slug of water to improve sweep, after which solvent alone may be injected to extract residual additive and oil by miscible extraction. A number of slugs of solvent, either by itself or with the additive may be injected, with intervening slugs of water and finally, water injection may be made to termination.

Abstract: A flooding process for oil recovery which is carried out under conditions of immiscibility or near-immiscibility, employs a displacing fluid such as carbon dioxide and an additive such as ethane which increases the solubility of the displacing fluid in the reservoir oil. The additive is injected in a slug with the displacing fluid preferably followed by a slug of water to improve sweep, after which displacing fluid alone may be injected to extract residual additive and oil. A number of slugs of displacing fluid, either by itself or with the additive may be injected, with intervening slugs of water and finally, water injection may be made to termination.

Abstract: The sweep efficiency of a steam flooding process is improved by injecting steam into the lower portion of the formation through an injection well until steam channeling or steam overriding has occurred, after which steam injection is terminated and an oxygen-containing gas such as air, oxygen-enriched air, or oxygen is injected into the formation to oxidize the residual oil in the portion of the formation where steam override or channeling has occurred. This forms an asphaltic material that decreases the permeability of that zone. Thereafter, steam injection is resumed and as a consequence of the oxidized asphaltic material plug, the steam moves into portions of the formation to mobilize viscous oil not swept by the initial injection of steam. During injection of the oxygen-containing gas production of oil may be terminated or continued. Multiple cycles of steam and oxygen-containing gas injection may be applied to a formation to better control sweep efficiency.

Abstract: A thermal oil recovery process in which steam is injected into a heavy oil-bearing formation through a horizontally-drilled injection well and oil is produced through a horizontal production well parallel to the injection well.

Abstract: In a thermal method for the recovery of oil from a subterranean, viscous oil-containing formation, a predetermined amount of steam in an amount not greater than 1.0 pore volume and an injection rate of 4 to 7 barrels of steam (cold water equivalent) per day per acre-foot of formation is injected into the formation via an injection well and oil is produced from the formation via a production well. The injection well is then shut-in for a variable time to allow the injected steam to dissipate its heat throughout the formation and reduce oil viscosity while continuing production of oil. Thereafter, a predetermined amount of hot water or low quality steam in an amount not greater than 1.0 pore volume is injected into the formation with continued production but avoiding steam breakthrough. Thereafter, production is continued until there is an unfavorable amount of water or steam in the fluids recovered.

Abstract: A method for the recovery of viscous oil from subterranean formations including tar sands by the injection of a mixture of carbon dioxide and steam into the formation through an injection well, after which formation fluids are recovered from the well in a cyclic manner, using the well alternately for injection and production. Incremental recovery is optimized by maintaining the ratio of carbon dioxide to steam within the range 200 to 300, preferably 230 to 270 SCF carbon dioxide per barrel of steam (with water equivalent) in the injected mixture.

Abstract: A method for the recovery of viscous oil from a subterranean, viscous oil-containing formation by injecting steam into the formation via at least one well at a sufficient temperature, rate, and in a sufficient amount to effect maximum visbreaking of the oil in place, terminating injection of steam and producing fluids including oil through the same well used for injecting steam. The injection-production cycle may be repeated for a plurality of cycles until the ratio of oil/water in the produced fluids is unfavorable.

Abstract: Oil is recovered by a CO.sub.2 miscible oil recovery method in which the CO.sub.2 minimum miscibility pressure of the oil-containing formation is lowered by injecting a coolant into the formation. The formation is then pressurized to a pressure at least that of the reduced CO.sub.2 minimum miscibility pressure by injecting a fluid therein. A slug of carbon dioxide is then injected into the formation at the formation pressure whereby the carbon dioxide is miscible with the formation oil and thereafter a driving agent is injected to displace the formation oil and carbon dioxide toward a production well from which oil is produced.

Abstract: A method for recovering oil from a subterranean, viscous oil-containing formation employing a cyclical injection-production program in which first a mixture of steam and solvent are injected after which fluids including oil are produced until the water cut of the produced fluids reaches 95 percent. Thereafter, the sequence of injection of a solvent/steam mixture and production of fluids including oil is repeated for a plurality of cycles. The ratio of solvent to steam is 2 to 10 volume percent. The mixture of solvent and steam is injected into the lower portion of the formation in which adequate fluid communication exists or in which a communication path is first established. In another embodiment, after the initial solvent/steam injection-production cycle, steam or hot water is injected into the formation followed by production and drawdown of the formation.

Abstract: A method for the recovery of oil from a subterranean, viscous oil-containing formation by injecting a predetermined amount of steam into the formation via a well completed in the middle portion of the oil-containing formation for a distance between 40 to 60 percent of the vertical thickness of the oil-containing formation, terminating injection of steam and producing fluids including oil through the same well used for the injection of steam. The steps of injecting steam and producing oil can be repeated for a plurality of cycles. Injecting steam through a selected completion interval in the middle of the formation induces maximum visbreaking of the viscous oil within the formation by controlling heat losses to the over and under strata.

Abstract: A subterranean, viscous oil-containing formation not greater than 2500 feet in depth is penetrated by at least one injection well extending into the lower portion thereof. A horizontal fracture is formed in the lower portion of the formation through the injection well. At least one spaced-apart production well penetrates the formation in fluid communication with the upper two-thirds or less of the formation. A slug of steam, about 0.35 to 0.45 pore volume, is injected into the injection well and fluids including oil are recovered from the formation via the production well. The injection well is shut-in for a predetermined period of time while continuing production of oil. Thereafter, a predetermined amount, about 0.03 to 0.10 pore volume, of hot water or low quality steam is injected into the injection well and production is continued until there is an unfavorable amount of water or steam in the fluids recovered.

Abstract: A subterranean, viscous oil-containing formation is penetrated by at least one injection well extending to the lower portion thereof. A cavity not greater than 0.10 pore volume is formed in the lower portion of the formation through the injection well. At least one spaced-apart production well penetrates the formation in fluid communication with the upper two-thirds or less of the formation. A slug of steam, about 0.35 to 0.45 pore volume, is injected into the injection well and fluids including oil are recovered from the formation via the production well. The injection well is shut-in for a predetermined period of time while continuing production of oil. Thereafter, a predetermined amount, about 0.03 to 0.10 pore volume, of hot water or low quality steam is injected into the injection well and production is continued until there is an unfavorable amount of water or steam in the fluids recovered.

Abstract: A method for the recovery of heavy oil from a subterranean silica-containing oil-containing formation comprising treating the formation with a slug of a hot aqueous solution containing sodium hydroxide and sodium bicarbonate capable of forming in-situ CO.sub.2 and metasilicate followed by injection of a drive fluid to aid in recovering the oil.

Abstract: A method for initiating an in-situ combustion process for the recovery of oil from a subterranean, viscous oil-containing formation wherein a combustible gas such as natural gas or methane and a mixture of oxygen and carbon dioxide containing 55 to 80 volume percent carbon dioxide is injected into a downhole burner in the injection well and ignited to produce combustion gases containing heat energy that pass into the formation. After the area of the formation surrounding the injection well reaches a temperature within the range of 500.degree. to 800.degree. F., injection of the combustible gas is terminated and injection of the mixture of oxygen and carbon dioxide is continued to initiate in-situ combustion in the formation. Thereafter, essentially pure oxygen is injected into the formation to support in-situ combustion in the formation for the recovery of oil therefrom.