Abstract: The invention is a method of recovering hydrocarbons from underground hydrocarbon formations penetrated by at least one injection well and at least one production well, which comprises injecting into the formation a mixture of hot water and about 0.1% to about 5% by weight of a hydrocarbon liquid having an aromatic content greater than about 30%. The hot water and hydrocarbon mixtures should be injected at a temperature of at least about 80.degree.C. Hydrocarbons and other fluids are recovered from a production well after a suitable period of time.

Abstract: The invention is a method for lowering the oxygen content of an aqueous polymer solution below 100 ppb, which comprises recirculating an aqueous polymer solution through microporous hollow fibers grouped in a module having an air tight interior which surrounds the hollow fibers. A vacuum is applied to the interior of the fiber module to enhance transportation of oxygen through the walls of the hollow fibers and out of the module interior.

Abstract: A series of water-soluble, or at least water-dispersible, corrosion inhibiting solutions are disclosed which contain about 2 ppm to about 70%, preferably about 3 ppm to about 200 ppm, of an ethoxylated, propoxylated alkylphenol amine represented by the formula: ##STR1## wherein R is hydrogen or an alkyl group containing about 5 to about 12 carbon atoms, R' is an alkyl group containing about 5 to about 12 carbon atoms, x equals about 1 to about 20, z equals about 1 to about 20, a equals about 1 to about 20, and b equals about 1 to about 20. The salt reaction products of the instant alkoxylated amine and an organic acid selected from the group consisting of hydroxyacetic acid, a fatty acid, a dicarboxylic acid, a dimer-trimer acid, an acidic phosphorus containing compound, and mixtures thereof are also effective in controlling sour and sweet corrosion.

Abstract: The invention is a method of group type separation of whole oils and bitumen by high performance liquid chromatography into fractions of asphaltenes, resins, aromatics, and saturated hydrocarbons. A multistep process is involved wherein the oil is initially solvated with a three part solvent mixture of methanol, acetone, and choroform. The solvated oil mixture is injected with a mobile phase into a cyano bonded phase column which will retain asphaltenes and resins, and pass through aromatics and saturated hydrocarbons. The unretained aromatics and saturated hydrocarbons are then injected into a silica column which will retain aromatics and pass through saturated hydrocarbons. Saturated hydrocarbons are recovered as they pass through the silica column. The resins, asphaltenes, and aromatics are recovered from the columns by a displacement material.

Abstract: The invention is a method of recovering hydrocarbons from an underground hydrocarbon formation which comprises drilling and completing at least three substantially parallel horizontal wells to form a substantially triangular well pattern within a hydrocarbon formation. The first well is placed relatively near the top of a hydrocarbon interval and the second and third wells are placed near the bottom of the interval on each side of the first well. A recovery fluid is injected into the formation through the second and third wells and hydrocarbons and other fluids are recovered through the first well.

Abstract: The invention is a method of restoring the permeability of an underground hydrocarbon formation adjacent to a wellbore which comprises injecting a first aqueous solution of hydrochloric or hydrofluoric acid into a formation interval where permeability has decreased due to polymer plugging and producing that acid out of the well after a soaking period. A second solution of about 200 ppm to about 2% by weight of chlorine dioxide is injected into the same interval and followed by a third solution of hydrochloric or hydrofluoric acid. The second and third solutions are allowed to soak in the formation for about 4 to about 48 hours before placing the well back on injection or production.

Abstract: A series of oil soluble to water-dispersible, corrosion inhibiting solutions are disclosed which contain about 2 ppm to about 70%, preferably about 3 ppm to about 200 ppm, of an ethoxylated, propoxylated dialkylphenol amine represented by the formula: ##STR1## wherein R and R' are alkyl groups containing about 5 to about 12 carbon atoms, x equals about 1 to about 10, and z equals about 2 to about 20. The salt and amide reaction products of the instant alkoxylated amine and an organic acid selected from the group consisting of hydroxyacetic acid, a fatty acid, a dicarboxylic acid, a dimer-trimer acid, an acidic phosphorus containing compound, and mixtures thereof are also effective in controlling sour and sweet corrosion. A method is also disclosed for protecting metal from corrosion by contacting the metal with an effective amount of the amine, or the amine/acid or amide reaction products, in a continuous or batch treatment.

Abstract: The invention is a method of recovering hydrocarbons from an underground vertical hydrocarbon reservoir having a substantial vertical thickness, an oil saturation relatively near residual oil saturation to gas, and at least one injection well and one production well penetrating the reservoir. The method comprises injecting a surfactant slug into the bottom of the reservoir above any water zone or aquifer, and driving the surfactant slug upwards through the reservoir by the use of some driving force. The driving force may be supplied by one or more of a combination of methods comprising producing the gas cap of the reservoir, producing hydrocarbons banked above the surfactant slug, or injecting fluid below the surfactant slug. Hydrocarbons are recovered at one or more production wells.

Abstract: The invention is a method for recovering residual hydrocarbons from a reservoir which has been previously swept by gas. The invention steps comprise drilling and completing at least one horizontal injection well relatively near the top of the reservoir, injecting a miscible solvent through the horizontal injection well to create a curtain of solvent falling through the previously gas swept reservoir, and producing hydrocarbons and other fluids that have been banked below the falling solvent curtain through a vertical or horizontal production well.

Abstract: The invention is a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, in which a saline polymer slug containing about 0.1% to about 3.0% of a drive fluid additive is injected into the formation after the injection of a saline surfactant slug. The drive fluid additive has the structure:R(C.sub.2 H.sub.4 O).sub.n H.sub.y (SO.sub.3 M).sub.xwhere R is a phenol, an alkylphenol having up to about 4 carbon atoms in the alkyl chain, or the product of reduction of lignin in the presence of carbon monoxide or hydrogen at a temperature greater than about 200.degree. C. and a pressure greater than about 100 psi, n has an average value of about 5 to about 30, x is 0 or 1, y is 1 if x is O, y is O if x is 1, and M is an alkali metal or ammonium ion.

Abstract: The invention comprises injecting about 5% to about 25% pore volumes of a recovery fluid simultaneously into an underground formation through at least two wells. One well which is destined to be the production well is shut-in for a soak period of about one to about 60 days while injection of the recovery fluid is continued through the second well. The shut-in well is then converted to a production well and hydrocarbons and other fluids are produced from the production well while recovery fluid is injected through the second well. The shut-in well is then converted to a production well and hydrocarbons and other fluids are produced from the production well while recovery fluid is injected through the second well.

Abstract: The invention is a method of recovering oil bypassed by a steam override zone. First, the production well is drilled below the oil producing zone into an underlying interval. The well perforations in the oil producing zone are closed off. The underlying interval is fractured to establish fluid communication between the underlying interval and the oil producing zone. The production well is completed for production through the fractured portion of the underlying interval. Finally, the steamflood is controlled to increase the pressure in the oil producing zone and drive the oil and steam downward to the new perforations in the underlying for production.

Abstract: The invention is a method of recovering hydrocarbons from underground hydrcarbon formations by injecting a mixture of carbon dioxide and a polar alcohol or polar glycol additive, said additive having less than about 9 carbon atoms. The mixture of carbon dioxide and additive is injected at a temperature and pressure above the critical temperature and pressure of carbon dioxide. The alcohol or glycol additive comprises about 0.1% to about 10% by weight of the injected mixture. After being injected through an injection well, the mixture is driven through the formation and the hydrocarbons and other fluids are recovered at one or more production wells.

Abstract: The invention is a method for recovering residual hydrocarbons from a reservoir which has been previously swept by gas. The invention steps comprise drilling and completing at least one horizontal injection well relatively near the top of the reservoir and relatively near a substantially vertically oriented boundary of the reservoir, drilling and completing at least one second injection well between the horizontal injection well and the vertical boundary of the reservoir, injecting a miscible solvent through the horizontal injection well to create a curtain of solvent falling through the previously gas swept reservoir, and injecting a drive fluid into the reservoir through the second injection well to drive the curtain of falling solvent horizontally through the reservoir. A production well is employed to produce hydrocarbons and other fluids that have been banked in front of the horizontally driven falling solvent curtain.

Abstract: The invention is a method of producing surfactants from lignin which comprises subjecting lignin to two reactions, alkylation with an alkyl chain having about 3 to about 24 carbon atoms at phenolic sites, and oxidation sufficient to break the lignin into smaller polymeric and monomeric units. The invention also includes using these lignin surfactants in surfactant floods for enhanced oil recovery.

Abstract: A method of producing surfactants from lignin is disclosed by reducing lignin in the presence of a carbon monoxide or hydrogen reducing agent at high temperature and pressure to produce low molecular weight lignin phenols and subjecting the lignin phenols to one or a combination of several reactions such as alkoxylation, alkylation, sulfonation, sulfation, alkoxysulfation, and sulfomethylation. The lignin surfactants so produced can be employed in a surfactant system to recover oil from underground formations.

Abstract: The invention is a method of recovering hydrocarbons with a surfactant flooding system, wherein the surfactant slug comprises about 0.1% to about 10% by weight of an alkylphenol lignin surfactant. The alkylphenol lignin surfactant is produced by reacting an alkylphenol having about 6 to about 15 carbon atoms in the alkyl chain with formaldehyde in basic solution at a temperature of about 50.degree. to about 120.degree. C. for about 15 minutes to about 3 hours to form a first reaction product. The first reaction product is then reacted with a kraft lignin in solution at a temperature of about 100.degree. to about 160.degree. C. for about 30 minutes to about 5 hours to form an alkylphenol lignin reaction product.

Abstract: Disclosed is an invention for shutting off a portion of a producing zone such as a steam override zone in a hydrocarbon producing wellbore. The bottom of the wellbore is filled with a material such as sand up to the bottom of the steam override zone. A pipe is placed and centralized in the middle of the wellbore so that the pipe extends throughout the steam override zone. A cement plug is placed around the centralized pipe while keeping the interior of the pipe free of cement. A larger cylindrical hole is then drilled through the cement plug by using the centralized pipe to center and guide a drill through the middle of the cement plug.

Abstract: A series of water-dispersible and oil-dispersible corrosion inhibiting solutions are disclosed which contain a polythioether represented by the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are H, a methyl group, or an ethyl group, X is a divalent organic radical selected from the group consisting of --C.sub.2 H.sub.4 --, --C.sub.4 H.sub.8 --, --C.sub.2 C.sub.4 OC.sub.2 H.sub.4 --, and C.sub.2 H.sub.4 SC.sub.2 H.sub.4 --, n is about 2 to about 40, and p is 0 or 1. The corrosion inhibitor solvent is preferably a hydrocarbon, such as an aromatic solvent or an alcohol, but may be water. Metal equipment can be protected through the use of the invention corrosion inhibiting solutions by contacting metal with an effective amount of inhibiting solution containing the polythioethers in a continuous exposure or batch treatment.

Abstract: The invention is a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which employs the steps of injecting a lignin amine surfactant slug, injecting an aqueous buffer slug of low salinity containing a polyacrylamide, injecting a high salinity aqueous drive fluid with polysaccharide, and recovering hydrocarbons and other fluids from the formation through a production well. The lignin amine surfactant slug is comprised of lignin, a primary amine having about 8 to about 18 carbon atoms and a sulfonate surfactant having an equivalent weight between about 200 and about 400 in the relative concentrations of about 1% to about 20% by weight of amine, about 10% to about 80% by weight of lignin, and about 10% to about 75% by weight of sulfonate surfactant.