Abstract: A process for removing water from heavy crude oil uses an inorganic salt which is a Group IA or Group IIA metal halide or nitrate salts. The crude oil is in the form of a water-in-oil emulsion with water content of 8% (by weight) or less. The salt is stirred into the crude oil. The resulting mixture is warmed. A water layer with added salts and an oil layer form. The salts are water soluble and settle out of the crude oil layer with the water.

Abstract: An improved glycol dehydration apparatus with a condenser on the reboiler water vapor vent to condense volatile carbon compounds, said condenser comprising a countercurrent flow shell-and-tube condenser with an annular space of at least three-quarters of an inch, said shell inlet in fluid communication with the glycol dehydration apparatus at a first location between the pressure reduction pump and the glycol reboiler and said shell outlet in fluid communication with the glycol dehydration apparatus at a second location between the glycol reboiler and the first location.

Abstract: Oil recovery by carbon dioxide flooding is increased by adding surfactants to the carbon dioxide at high pressures such that an emulsion with water will be formed in the pore spaces of rock. The emulsion diverts flow of carbon dioxide to rock containing higher oil saturations.

Abstract: The invention is a method for recovering hydrocarbons from an underground hydrocarbon reservoir penetrated by at least one injection well and at least one production well, which comprises injecting into the reservoir through an injection well an aqueous caustic solution comprising greater than 0.1% and less than 1.0% lignosulfonate by weight to shift the optimal salinity for enhanced oil recovery of the caustic solution to a relatively higher salinity, and producing hydrocarbons and other fluids through a production well.

Abstract: The disclosed invention is a group of steam foaming agents for injection with steam and a non-condensable gas to decrease permeability in steam swept zones and increase oil recovery. The foaming agents have the general formula:RO(R'O).sub.n R"CO.sub.2 Mwhere R is an alkyl radical, branched or linear, having from about 8 to about 24 carbon atoms in the alkyl chain, R' is ethylene, propylene or a mixture of ethylene and propylene, n has an average value of about 3 to about 11, R" is methylene or ethylene, and M is an alkali metal or ammonium ion.

Abstract: The disclosed invention is a group of steam foaming agents for injection with steam and a non-condensable gas to decrease permeability in steam swept zones and increase oil recovery. The foaming agents have the general formula:RO(R'O).sub.n R"SO.sub.3 Mwhere R is an alkyl radical, branched or linear, or an alkylbenzene, alkyltoluene or alkylxylene group, having from about 8 to about 24 carbon atoms in the alkyl chain, R' is ethyl, propyl or a mixture of ethyl and propyl, n has an average value of about 1 to about 20, R" is ethyl, propyl, hydroxypropyl or butyl and M is an alkali metal or ammonium ion.

Abstract: The disclosed invention is a one step or two step process for extracting surfactant from produced emulsions of oil, water and surfactants, concentrating the surfactants into a relatively small volume emulsion middle phase that can be reutilized in surfactant flooding and separating substantial quantities of salable oil from the emulsions.In the two step process, a sulfonated alkyl benzene is added and mixed with the emulsion, which partitions upon settlement into three phases, a clean oil phase, a first microemulsion middle phase and an aqueous phase. An ethoxylated phenol is then added and mixed to the first middle phase to yield at least two more similar phases with the middle phase containing the concentrated surfactants. Alternately, the sulfonated alkyl benzene and the ethoxylated phenol can be combined and added in a one step extraction process.

Abstract: A method is disclosed for restoring permeability of injection wells which have become plugged with polymer residue, protein debris, biological matter and the like. The method includes treating the well for a period of time with an aqueous solution containing hydrogen peroxide and optionally a surfactant.

Abstract: Disclosed is a surfactant waterflooding enhanced oil recovery process and surfactant fluid suitable for use in an enhanced oil recovery process which accomplishes an increase in the amount of oil recovered over prior art methods. The surfactant fluid contains an alkylpolyalkoxy sulfate or alkylarylpolyalkoxy sulfate, or an alkylpolyalkoxyalkylene sulfonate or alkylarylpolyalkoxyalkylene sulfonate, either alone or in combination with an organic sulfonate anionic surfactant, such as petroleum sulfonate. The optimum average degree of ethoxylation of the alkoxy sulfate or alkoxy sulfonate surfactant is identified, and the surfactant fluid is formulated with a mixture of ethoxylated and sulfated or ethoxylated and sulfonated surfactants, having a broad even range of degree of ethoxylation.

Abstract: An aqueous treating solution is disclosed for surfactant flooding operations to increase oil recovery. The treating solution comprises water, one or more surfactants, one or more solubilizers and a sulfonated dicyclopentadiene compound which permits a reduction in the needed quantities of surfactant and solubilizer without loss of surfactant stability and activity or oil recovery efficiency.

Abstract: Surfactant waterflooding in oil formations containing high salinity water, e.g. water whose salinity is in excess of 50,000 part per million total dissolved solids and whose temperatures exceed about 100.degree. to 150.degree. F. is accomplished by injecting into the formation an aqueous solution of an alkylarylpolyalkoxyalkylene sulfonate containing a stabilizing amount of a normally liquid hydrocarbon. The amount of hydrocarbon employed is less than 1% and below the amount which would form a discrete discontinuous hydrocarbon zone, i.e. less than the amount of hydrocarbon which forms a conventional emulsion is employed to stabilize the surfactant-containing solution.

Abstract: Oil is recovered from an underground petroleum reservoir which contains a brine having a salinity of from 50 to 220 kg/m.sup.3 total dissolved solids by injecting an alkylarylpolyalkoxy sulfate or alkylpolyalkoxy sulfate surfactant that exhibits phase stability in the brine or diluted brine. The surfactant is injected in an aqueous solution which is prepared with diluted brine which has a salinity slightly less than that required to cause partitioning of the surfactant out of the aqueous phase into the oil-water interface or oil phase. The injection of surfactant is followed by the injecting of a driving slug comprised of either diluted brine or thickened diluted brine.

Abstract: The effectiveness of a surfactant waterflooding oil recovery process employing an aqueous, saline fluid containing an alkylpolyalkoxy sulfate or an alkylarylpolyalkoxy sulfate is increased substantially if the fluid is subjected to a high shear for a predetermined period of time prior to injecting the fluid into the oil-containing formation. The surfactant fluid should be subjected to a shear rate of at least 150 and preferably at least 250 reciprocal seconds for a period of time of at least 0.1 minutes and preferably at least 0.5 minutes. The improvements obtained by shearing the surfactant fluid include increased stability of the solution, i.e., resistance to separation into separate, distinct phases, reduced turbidity of the fluid which provide improved injectivity with reduced well plugging problems, and attainment of significantly lower interfacial tension between the aqueous surfactant fluid and formation petroleum, and more effective oil displacement from reservoir rock.

Abstract: Petroleum is extracted from a subterranean reservoir by injecting into injection wells an aqueous surfactant solution wherein the surfactant is a mixture of mono- and di-alkyl benzene polyethoxy alkyl sulfonates wherein the alkyl group contains the same number of carbon atoms in both components of the surfactant, driving the surfactant solution through the reservoir and recovering petroleum from production wells penetrating the reservoir. The fluid composition of the surfactant mixture is also claimed.

Abstract: The conformance of a supplemental oil recovery process in a formation containing at least two zones of varying permeability is improved by flooding until the higher permeability zone has been depleted, after which a fluid is injected into the high permeability zone, said fluid having relatively low viscosity at the time of injection and containing surface active agents which promote the formation of a coarse emulsion in the flow channels of the formation which reduces the permeability of the high permeability zone. Most of the emulsion-forming fluid invades the previously swept high permeability zone; however, some invasion of the low permeability zone occurs immediately adjacent to the wellbore. The wellbore is washed with a low, C.sub.1 to C.sub.6 alcohol, to remove the emulsion formed immediately adjacent to the wellbore.

Abstract: Oil is recovered from an underground petroleum reservoir which contains a brine having a salinity of from 50 to 220 kg/m.sup.3 total dissolved solids by injecting an alkylarylpolyalkoxyalkylene sulfonte surfactant that exhibits phase stability in the brine or diluted brine. The surfactant is injected in an aqueous solution which is prepared with diluted brine which has a salinity slightly less than that required to cause partitioning of the surfactant out of the aqueous phase and to the oil-water interface or oil phase. The injection of surfactant is followed by the injection of a driving slug comprised of either diluted brine or thickened diluted brine.

Abstract: The conformance of a surfactant waterflood oil recovery process in a formation containing at least two zones of varying permeability, the permeability of one zone being at least 50 percent greater than the permeability of the other zone, is improved by flooding until the higher permeability zone has been depleted, after which a small amount of oil is injected followed by water injection for a period of time sufficient to resaturate the swept zone at least adjacent to the injection well. Next, a fluid is injected into the high permeability zone, said fluid having relatively low viscosity at the time of injection and containing surface active agents which promote the formation of a coarse emulsion in the flow channels of the formation which reduces the permeability of the high permeability zone.

Abstract: The effectiveness of an aqueous, saline surfactant fluid, especially one containing as essentially the only surfactant an alkylpolyalkoxyalkyl sulfonate or an alkylarylpolyalkoxyalkyl sulfonate for oil recovery by surfactant flooding is increased substantially if the fluid is subjected to a high shear rate for a predetermined period of time prior to injecting the fluid into the oil containing formation. The surfactant fluid should be subjected to a shear rate of at least 150 and preferably at least 250 reciprocal seconds for a period of time of at least 0.1 minutes and preferably at least 0.5 minutes. The improvements obtained by shearing the surfactant fluid include increased stability of the solution, i.e.

Abstract: The conformance of an aqueous flooding oil recovery process, including steam, hot water or surfactant or other chemicalized water flood process, in a formation containing at least two zones of different permeability, the permeability of one zone being at least 50 percent greater than the permeability of the other zone, is improved by flooding until the higher permeability zone has been depleted, after which a fluid is injected into the depleted, high permeability zone, said fluid having relatively low viscosity at the time of injection and containing a mixture of at least two surface active agents which promotes the formation of a coarse emulsion in the flow channels of the formation which reduces the permeability of the high permeability zone. Since the viscosity of the fluid injected into the previously water flooded, high permeability zone is no greater than water, it is injected easily into the zone and moves through substantially the same flow channels as water would move in the formation.

Abstract: The amount of oil recoverable from a subterranean, petroleum-containing, permeable formation by surfactant water flooding is improved if at least two separate slugs of surfactant-containing fluid are injected into the formation, the first being a fluid containing a surfactant which is an effective emulsifier for the petroleum in the formation and the second surfactant fluid containing a surfactant which does not produce an emulsion between the aqueous fluid and the formation petroleum, but which is effective for achieving maximum oil recovery, or for achieving the minimum interfacial tension between the aqueous phase present in the flow channels of the formation and the formation petroleum. In one embodiment, both surfactants are an aliphatic (e.g. alkyl) or alkylarylpolyalkoxyalkyl sulfonate, differing only in the average number of alkoxy groups per molecule. The first emulsifying surfactant contains an average of from 0.2 to 0.8 fewer alkoxy groups than the second surfactant.