Abstract: Injection of steam or other thermal fluid for recovery of heavy crude oil is accompanied by or followed by injection in the same well of a solution of petrochemical sulfonate and a co-surfactant, the co-surfactant being either an olefin sulfonate or a propane sulfonate of an ethoxylated alcohol or alkyl phenol. The surfactant mixture is followed by injection in the same well of a water-soluble polymer solution and additional oil is recovered from production wells.

Abstract: The invention is a method for decreasing formation permeability in an underground formation around a wellbore by injecting an aqueous fresh water solution comprising about 0.9% to about 3.0% by weight of hydroxy propyl cellulose having an average molecular weight greater than about 1,000,000 and about 0.4% to about 3.0% by weight of an alkali metal dodecyl sulfate in the ratio of about 3:1 to about 1:1.5 of cellulose to sulfate, said formation must contain a connate brine having a salinity greater than about 20,000 ppm TDS, or an injected brine having a salinity greater than about 20,000 ppm TDS to mix and react with the aqueous solution to form a gel. The invention is also a method for forming a high viscosity gel by mixing hydroxy propyl cellulose, alkali metal dodecyl sulfate and sufficient salinity.

Abstract: The invention is a method of producing hydrocarbons from a region bounded by two vertical wells and a horizontal well, which comprises injecting a gas through a first vertical well, concurrently performing a cyclic injection, soak and production of gas through a horizontal well, converting the first well to production after the gas injected from the first well reaches the area affected by gas from the horizontal well, and injecting gas through a second vertical 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, which comprises injecting into an underground formation through an injection well about 0.05 to about 1.0 pore volumes of an aqueous surfactant slug comprising about 0.1% to about 10% by weight of a surfactant system, injecting a drive fluid into the formation through the injection well to push the surfactant slug towards the production well, and recovering hydrocarbons at the production well, said surfactant system comprised of a lignin phenol surfactant, a lignin, a primary amine having about 8 to about 20 carbon atoms, and a solubilizer.

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 foam method for improving conformance during a steam flood or carbon dioxide flood in an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises injecting into an injection well about 0.05% to about 2% by weight aqueous surfactant solution, and then injecting into the injection well a flooding medium of steam or carbon dioxide, said surfactant solution comprising a surfactant having the formulaR(C.sub.2 H.sub.4 O).sub.n SO.sup.4 M.sup.+where R is a lignin phenol produced by reducing lignin in the presence of a reducing agent 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 2 to about 25, and M.sup.+ is an alkali metal or ammonium cation.

Abstract: A sacrificial agent solution which is compatible with high molecular weight mobility control polymers for enhanced oil recovery, said solution comprising about 0.1% to about 5% by weight of a lignosulfonate and about 0.01% to about 5% by weight of a polyalkylene glycol having a relatively low molecular weight.

Abstract: The invention is a method of evaluating a sample of an underground formation such as drill cuttings to determine the producibility of any hydrocarbons present in the formation by solvating a sample in a polar solvent which will solvate asphaltenes, solvating the sample in an aliphatic solvent which will solvate most crude fractions without solvating asphaltenes, quantitatively measuring the emission fluorescence at a wavelength below 400 nm of both solvated samples at an excitation wavelength at which most petroleum compounds fluoresce, and determining the producibility of any hydrocarbon present in the sample by comparing the emission fluorescence of the two samples to previous correlations made between fluorescence and known producibility.

Abstract: The disclosed invention is a method of injecting a solution or emulsion containing about 0.05% to about 10% by weight of urea as a sacrificial agent for surfactants into an underground formation in enhanced oil recovery operations, said underground formation having a temperature greater than about 130.degree. F.

Abstract: The invention is a process for separating a mixture of saturated hydrocarbons into normal paraffins, branched chain paraffins, and cyclic paraffins which comprises contacting said mixture with a series of two molecular sieves comprising a first silicalite and a second silicalite which have different retention conditions. One of the silicalites is selected so that it will retain normal paraffins and pass through branched chain paraffins and cyclic paraffins. The second silicalite is selected so that it will retain normal and branched chain paraffins and pass through cyclic paraffins. The two molecular sieves are employed in series so that the mixture of saturated hydrocarbons can be separated into normal paraffins, branched chain paraffins, and cyclic paraffins.

Abstract: The invention is a method of evaluating a sample of an underground formation to determine the hydrocarbon content of any hydrocarbons present in the formation. It involves the steps of solvating a known volume of a sample in a known volume of a solvent which will solvate hydrocarbons, quantitatively measuring with a fluorometer the emission fluorescence below about 400 nanometers of the solvated sample at an excitation wavelength at which most petroleum compounds fluorescence, and determining the hydrocarbon content of any hydrocarbon present in the sample by comparing the emission fluorescence of said solvated sample to previous correlations. The previous correlations are drawn between known hydrocarbon contents of samples and the emission fluorescence of the known samples in said solvent.

Abstract: A method is disclosed for increasing the recovery of oil in enhanced oil recovery operations employing anionic surfactant by blending a taurine with said anionic surfactant. The taurine may also increase the salt and divalent ion tolerance of the anionic surfactant.

Abstract: A method for producing a homogeneous oil-in-water microemulsion by first creating a surfactant, oil and water mixture, adding salt to the mixture in a sufficient quantity to drive the mixture into a Type III or Type II(+) phase regime, preparing a solution having a selected salinity lower than the salinity of the Type III or Type II(+) phase regime, and mixing a sufficient amount of the lower salinity solution with the Type III or Type II(+) regime to invert the Type III or Type II(+) regime into a Type II(-) oil-in-water microemulsion. The microemulsion may be used in a surfactant flood to recover hydrocarbons from underground formations.

Abstract: The disclosed invention is a method for reducing lost circulation in wellbores. In the method, a liquidized sand, comprised of a particulate material, a resin, and a carrier fluid comprising a surfactant mixed with air, is injected into the wellbore. The liquidized sand is then allowed to solidify in the lost circulation area, thereby sealing the area and reducing or eliminating the lost circulation.

Abstract: The invention is a liquid membrane process for separating a gaseous stream into a permeate stream of gases having predominantly lower equilibrium K values and a stream of gases having predominantly higher equilibrum K values, wherein the feed stream and the liquid membrane are operated at a temperature and pressure near a dew point of the feed stream in the two phase liquid/gas region of the phase envelope so that condensate from the feed stream will supply the liquid for the liquid membrane. The liquid membrane process is especially useful to separate hydrocarbon gases, such as a natural gas feed stream containing a large concentration of methane.

Abstract: Petroleum is extracted from a subterranean reservoir by injecting into injection wells an aqueous polymer solution wherein the polymer is stabilized against viscosity deterioration by treating the reservoir with an effective amount of urea in an aqueous solution.

Abstract: A series of water-dispersible corrosion and scale inhibiting solutions are disclosed which contain the reaction product of a phosphonate compound containing at least two phosphonate groups of the formula ##STR1## and an ethoxylated, propoxylated alkylphenol amine represented by the formula ##STR2## wherein R is an alkyl group containing about 5 to about 12 carbon atoms, X equals about 1 to about 20, and z equals about 1 to about 20.

Abstract: The invention is a method of producing a homogeneous oil-in-water microemulsion comprised of oil, brine and surfactant, wherein the oil has a equivalent alkane carbon number higher than the crude oil which is to be recovered by the microemulsion. A mixture of oil, water and surfactant is prepared in the same relative ratios to oil and surfactant as in the microemulsion desired to be injected, but at higher concentration relative to water and salt than in the microemulsion to be injected. The cloudy mixture is stirred while adding salt until the mixture changes to a clear oil-in-water microemulsion concentrate. The microemulsion concentrate is then mixed with sufficient water of the proper salinity to form the oil-in-water microemulsion desired to be injected.

Abstract: The invention is a method for isolating a sample of oilfield production without shearing the sample, which includes a multistep method of using a chamber to isolate a sample of fluid from a flowline by transferring the sample from the flowline without a significant pressure drop. This involves placing a valved isolation chamber in fluid communication with a sampling port of an oilfield production flowline, the isolation chamber consists of a closed vessel, a first entry port into the vessel, and a first exit port out of the vessel controlled by a first valve. The sampling port valve is opened while the first valve of the isolation chamber is closed to permit pressure within the isolation chamber to equalize with pressure within the flowline. The first valve is then opened to permit oilfield production to pass from the flowline through the sampling port and the first entry port into the isolation chamber and out of the first valve.

Abstract: The invention is a method of fracturing an underground formation penetrated by a wellbore, which comprises injecting into a formation a mixture of carbon dioxide and a polar alcohol or polar glycol additive at a temperature and pressure above the critical temperature and pressure of carbon dioxide. The alcohol or glycol additive should have less than about 9 carbon atoms and comprises about 0.1% to about 10% by weight of the injected mixture. The mixture is injected with sufficient volume and pressure to cause a fracture to be formed in the underground formation.