Abstract: A process for recovering hydrocarbons from a subterranean hydrocarbon bearing formation penetrated by an injection well and a production well which comprises injecting an aqueous drive fluid into the formation and forcing the drive fluid through the formation to recover the hydrocarbons from the production well.

Abstract: Novel deacetylated polysaccharide biopolymers having improved viscosity/filtrability/injectability, well adopted for the secondary and tertiary recovery of oil deposits, are conveniently prepared by (i) acidifying an aqueous polysaccharide composition, e.g., a carbohydrate fermentation broth, with nitric acid to a pH of from about 2 to 0.1, (ii) heat-treating said acidified composition at a temperature of from about 50.degree. to 100.degree. C. for from about 5 to 60 minutes, and (iii) cooling said heat-treated composition and adjusting the pH thereof to a value of from about 5 to 7.

Abstract: A method is provided for recovering oily waste from oily waste accumulations underground comprising sweeping the oily waste accumulation with hot water to recover said oily waste, wherein said area treated is isolated from surrounding groundwater hydraulically. The hot water may be reinjected after the hot-water displacement or may be treated to conform to any discharge requirements.

Abstract: A composition of matter wherein amino resins such as melamine formaldehyde ("MF") resins co-gel and crosslink with polymers useful for profile control where said polymers have amine, amide, hydroxyl and thiol functionalities. Resulting gels are useful as profile control agents for high temperature reservoirs during a water-flooding operation.

Abstract: A composition is disclosed which comprises:(A) a compound represented by the formula ##STR1## wherein: R.sup.1 and R.sup.2 are independently hydrocarbyl groups of from about 2 to about 24 carbon atoms; R.sup.3 is a trivalent hydrocarbyl group of from 1 to about 16 carbon atoms; R.sup.4 is CH.sub.2 CH.sub.2 O, CH.sub.2 CH.sub.2 CH.sub.2 O or a mixture thereof; X is SO.sub.3.sup.-, SO.sub.4.sup.- or COO.sup.- ; and Y is an alkali metal or ##STR2## wherein R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are independently hydrogen or methyl; and n is a number ranging from zero to about 15; and(B) a compound represented by the formula R.sup.9 -(R.sup.10).sub.m A.sup.-D.sup.+wherein: R.sup.9 is a hydrocarbyl group of from about 8 to about 24 carbon atoms; R.sup.10 is CH.sub.2 CH.sub.2 O, CH.sub.2 CH.sub.2 CH.sub.2 O or a mixture thereof; A is SO.sub.3.sup.-, SO.sub.4.sup.- or COO.sup.- ; D is an alkali metal or ##STR3## wherein R.sup.11, R.sup.12, R.sup.13 and R.sup.

Abstract: A microbial process is provided for selectively plugging a high permeability stratum or zone in a subterranean reservoir. Starved bacteria of reduced size are injected into the zone. A poor-nutrient media is either simultaneously or subsequently thereafter injected into the zone to substantially uniformly resuscitate the starved bacteria. Thereupon, the bacteria regain full cell size, proliferate, and commence production of biofilm-forming exocellular polysaccharides. The biofilm is functional to selectively seal off the high permeability zone of the formation and reduce aqueous flow through the zone.

Abstract: The present invention is a bacteria and its use in a Microbial Enhanced Oil Recovery (MEOR) process. Any one of two newly isolated strains of bacteria are injected downhole in a petroleum reservoir to modify its profile. This bacteria has the capability to plug the zones of higher permeability within the reservoir so that a subsequent waterflood may selectively enter the oil bearing less permeable zones. The injected water is used to drive this oil to an area where it may then be recovered.

Abstract: Aqueous solutions of polysaccharide biopolymers, e.g., Xanthomonas/carbohydrate fermentation worts, are treated with mutanase-containing enzymes to improve the filterability and injectability thereof, and are well adapted, e.g., for secondary and tertiary hydrocarbon (petroleum) recovery by waterflooding therewith.

Abstract: The present invention is a process for in situ biodegradation of spilled hydrocarbons. The process involves drawing oxygen into a hydrocarbon contaminated zone. A borehole is drilled into the contaminated zone and gas is evacuated at high rates out of the borehole to thereby draw oxygen into the contaminated zone. Surprisingly, the carbon dioxide concentration in the evacuated gas remains high even at the high flow rates.

Abstract: Process for preparing Xanthomonas heteropolysaccharide from Xanthomonas campestris NCIB 11854 and use of the latter, e.g. as viscosity modifier in an aqueous solution, and in a drilling fluid and use in connection with well treatments, and enhanced oil recovery.

Abstract: A process for the degradation with acid of a viscous microbial polysaccharide formulation which is applied in oil and/or gas reservoir operations, wherein the polysaccharide formulation contains an amount of a salt or a salt mixture which is sufficient to adjust the transition temperature of the polysaccharide such that it is close to the reservoir operating temperature. A process for the preparation of an acid degradable polysaccharide formulation and a polysaccharide formulation.

Abstract: The invention relates to a process for reducing or completely stopping a water inflow from a formation towards a producing well.The process according to the invention, using the injection of an aqueous dispersion of hydrosoluble polysaccharide in this producing well, blocks the water inflow without however decreasing the oil and gas flow towards this well.This process is particularly of high interest when the produced water is hot, e.g. at a temperature from 70.degree. to 130.degree. C., and/or salted, e.g. of a salt content of at least 30 g/l.This process is used for oil and/or gas production.

Abstract: A process for recovering hydrocarbons from a subterranean, hydrocarbon-bearing formation comprising: (a) introducing microbes into the formation, the microbes being effective to render at least a portion of the hydrocarbons in the formation more easily recoverable; (b) passing electrical energy through at least a portion of the formation to increase the mobility of the microbes in the formation; and (c) recovering hydrocarbons from the formation.

Abstract: An apparatus and method for withdrawing gaseous decomposition products from a refuse dump. Disposed at various locations in the refuse are gas collection mechanisms, such as gas wells, drainage systems, etc., each of which is connected via a gas withdrawal line with a collector, from which the gas is withdrawn for further utilization. Disposed in each gas withdrawal line is a sensor and a regulatable shutoff device. The sensor transmits the content of a characteristic constituent of the gas flow in a given gas withdrawal line to a measuring and control unit, which monitors the gas flow volume as a function of a comparison of the sensor signals with preset threshold values. If the sensors indicate that the content of the characteristic constituent of the gas flow exceeds or drops below the preset threshold values, the measuring and control unit opens or closes the associated shutoff device by an appropriate amount.

Abstract: A method for reducing the gelation time of a biopolysaccharide which utilizes a hydroxide of an alkaline earth metal in an aqueous solution containing said biopolysaccharide wherein the mixture is afterwards complexed with a polyvalent metal ion. The resultant stable gel can be injected into a hydrocarbonaceous fluid formation for the recovery of hydrocarbonaceous fluids.

Abstract: Aqueous solutions of polysaccharide biopolymers, e.g., Xanthomonas/carbohydrate fermentation worts, are heat treated for more than 5, but less than 60 minutes, at a pH ranging from 3.5 to 6.2, to improve the viscosifying, filterability and injectability properties thereof, and are well adapted, e.g., for secondary and tertiary hydrocarbon (petroleum) recovery by waterflooding therewith.

Abstract: The permeability of subterranean oil-bearing formations is selectively reduced by the injection into the formation of the non-xanthan, anionic heteropolysaccharide S-130 produced by fermentation with a microorganism of the Alcaligenes species. The polymer forms shear-thinning, viscous solutions which selectively enter the more highly permeable regions of the formation and form a gel plug in them to reduce their permeability. The polymer forms gels which are stable under a wide range of reservoir conditions including high temperatures.

Abstract: Materials of particular utility in separating hydrocarbon values from mineral deposits, e.g. bitumen from tar sands, are prepared by a microbiological fermentation process using certain selected microorganisms. The fermentation process is conducted under aerobic conditions, with the selected microorganisms growing on a hydrocarbon substrate. The materials have surfactant properties, in greater or lesser degree. The materials may be subsequently separated from the fermentation broth, or alternatively the broth may be used as is, since it contains relatively large proportions of suitable separation effecting materials.

Abstract: Polymers used in enhanced oil recovery operations, including polysaccharides, polyamides and cellulose derivatives may be crosslinked by the use of organic nitrogen compounds bearing at least two positively charged nitrogen atoms. Suitable crosslinking agents include the salts of aliphatic and aromatic diamines and bis (quaternary ammonium) compounds. The crosslinked copolymers may be used for mobility and permeability control purposes. The crosslinking agents are effective over a wide range of pH conditions to form stable gel structures with the polymers.

Abstract: An enhanced oil recovery process comprising injecting into an oil-bearing formation a sacrificial agent to adsorb on and occupy active sites of the formation matrix and introducing into the formation microbial cells or agents which produce metabolic products in-situ thereby enhancing oil displacement from the formation.

Abstract: The present invention is a process to stimulate the biooxidation of a contaminant in a subterranean formation by introducing an aqueous solution into the formation. The concentration of the hydrogen peroxide is increased thereby acclimating the biota to higher concentrations of hydrogen peroxide. Periodically the concentration of the hydrogen peroxide is increased for a short time sufficiently to be toxic to the biota at or relatively adjacent to the site of introduction, thereby increasing the permeability of the formation at or adjacent to the site of introduction.

Abstract: A method of preparing viscous aqueous liquids containing Xanthomonas polysaccharides for injection into wellbores. The Xanthomonas polysaccharide is dispersed into relatively fresh water. This dispersion of polysaccharide is then mixed with a relatively saline aqueous makeup solution to provide the final thickened aqueous liquid. Trivalent metal ions may be incorporated in the polysaccharide dispersion prior to the addition of the aqueous saline solution in order to complex the polysaccharide. The complexed polysaccharide solutions are useful for selectively blocking high permeability regions in stratified reservoir formations by injecting the complexes into the formation at shear rates which cause a reversible disruption of the complex; the disrupted complexes penetrate the high permeability regions and when the shearing forces decrease at a certain distance from the wellbore, the complexes re-form to block the high permeability regions selectively.

Abstract: A method of controlling and selectively reducing the permeability of zones in an oil-bearing underground formation which have higher permeabilities than the surrounding zones by injection of exopolymer producing microorganisms into the oil-bearing formation is described. The exopolymer production of the microorganisms used in the method is controlled by regulation of the availability to the microorganisms of a compound such as sucrose which triggers exopolymer production.

Abstract: Subterranean paths of water flow are impeded or changed by the facilitation of microbial growth therein. Either indigenous bacterial growth may be stimulated with nutrients or the formation may be first seeded with bacteria or their spores which inhibit fluid flow after proliferation. These methods and bacteria are usable to alter the flow of water in a waterflooded oil formation and to impede the outflow of contaminated water.

Abstract: A method is disclosed for recovering petroleum from a subterranean reservoir penetrated by at least one injection well and at least one production well comprising: injecting into the reservoir through the injection well a surfactant slug comprising an aqueous solution containing about 0.001 to about 5% by weight of an amphoteric surfactant and an effective amount of a high molecular weight homopolysaccharide gum thickener derived from fungus strains of the genus Schlerotium to provide the surfactant slug with a viscosity exceeding the viscosity of the petroleum in the reservoir; and recovering fluid from the production well.

Abstract: A process for recovering hydrocarbons from a subterranean hydrocarbon bearing formation penetrated by injection well and a production well includes the steps of injecting into the formation via an injection well an aqueous drive fluid comprising water and more than about 200 parts per million of Beta-(1.fwdarw.6)-D-glucan having an average molecular weight of more than about 2.times.10.sup.4 and comprising recurring units of the disaccharide gentiobiose: ##STR1## forcing said aqueous drive fluid through the formation and recovering hydrocarbons from the production well. The process also includes using a more concentrated solution of the glucan, more than about 2,000 parts per million, as a vertical conformance agent. The invention also includes a concentrate of the glucan in dimethylsulfoxide or in a 4 molar or higher concentration of aqueous urea which is diluted to form the aqueous drive fluid.

Abstract: A pure culture of Bacillus licheniformis strain JF-2 (ATCC No. 39307) and a process for using said culture and the surfactant lichenysin produced thereby for the enhancement of oil recovery from subterranean formations. Lichenysin is an effective surfactant over a wide range of temperatures, pH's, salt and calcium concentrations.

Abstract: In a polymer flood, where bacterial contamination frequently causes a loss in viscosity of the polymer, the viscosity of the polymer solution is maintained by the use of a xanthan polymer modified by methylation of a portion of the subunit sugar residues of the xanthan base.

Abstract: An aqueous heteropolysaccharide solution is treated to improve its injectivity into a subterranean hydrocarbon reservoir by passing the solution through a colloid mill.

Abstract: A thermostable, viscous xanthan polysaccharide solution prepared by the process of heating a xanthan polysaccharide solution in the presence of at least one C.sub.1 to C.sub.10 alkyl or C.sub.3 to C.sub.10 cycloalkyl substituted primary or secondary mono- or diamine having an upper limit of a total of 15 carbon atoms under conditions sufficient to form a thermostable, viscous xanthan polysaccharide solution.The thermostable, viscous xanthan polysaccharide solution may be used as a mobility buffer in a process for the enhanced recovery of oil.

Abstract: A method of treating a subterranean oil-bearing formation having an in-situ microbial population therein. In a preferred embodiment, the method permits increased oil recovery by stimulating the growth of the in-situ microbial populations. Nutrients, including nitrogenous-and phosphorous-containing compounds, are injected into the formation concurrent with or subsequent to a waterflood. The nutrients can be injected sequentially, and the sequence can be varied or repeated as necessary. Growth of the microorganisms increases displacement and sweep efficiency of a subsequent waterflood.

Abstract: A stable xanthan solution with superior filterability and subterranean injectivity characteristics comprising biopolymer and a chelating agent selected from aliphatic alpha-hydroxy acids having from about 2-7 carbon atoms; aliphatic and aromatic beta-keto compounds having from about 4-9 carbon atoms; or 2- and 4-pyrones having a hydroxyl group alpha to the carbonyl and having 5 or 6 carbon atoms; said chelating agent being present in an amount of at least about 1.0 ppm of the total solution. A method of enhancing oil recovery comprising employing as a mobility control solution in oil-bearing formations a mixture of xanthan biopolymer and a chelating agent is also disclosed.

Abstract: A method of controlling and selectively reducing the permeability of zones in an oil-bearing underground formation which have higher permeabilities than the surrounding zones by injection of exopolymer producing microorganisms into the oil-bearing formation is described. The exopolymer production of the microorganisms used in the method is controlled by regulation of the availability to the microorganisms of a compound such as sucrose which triggers exopolymer production.

Abstract: A method of tertiary oil recovery from petroleum-containing formations at elevated temperature comprises injecting a substantially oxygen-free aqueous saline solution of water-soluble polysaccharide biopolymer treated at pH of at least 5 by the addition of alkali metal borohydride as viscosity stabilizer.

Abstract: Residual polymeric material from a post-secondary oil recovery operation is consumed by microorganisms injected into the oil-bearing reservoir. The resulting metabolic products, including surfactant-acting substances, enhance additional oil production from the reservoir.

Abstract: A post-primary oil recovery process is provided in which carbon dioxide-tolerating microorganisms are injected into an oil-bearing subterranean formation and feed on nutrients which are extracted from the oil by carbon dioxide injected and maintained under a pressure of at least about 500 psig. The products of microorganism growth enhance petroleum recovery from the formation.

Abstract: A process for recovering oil from a subterranean formation using a modified aqueous saline heteropolysaccharide solution as mobility control agent, said aqueous solution containing at least 0.5 wt. % of inorganic salts wherein the solutions are stabilized against loss of pyruvate groups on heat treatment by a process which comprises preparing an aqueous solution containing heteropolysaccharide and inorganic salts, adding a buffer to control pH between about 6.5 and 10.0, heating to a temperature of at least 100.degree. C. and maintaining the pH at from 6.0 to 9.5 during heating, then removing cell debris. The buffered solutions do not suffer loss of pyruvate content which leads to viscosity loss.

Abstract: The filtrability of xanthan gum aqueous solutions is improved by an enzymatic treatment in two successive steps, the first step by means of a polysaccharase and the second step by means of a protease, the operating conditions of each step being such that the corresponding enzyme is active in said step.

Abstract: A process for recovering crude oil from a subterranean formation using aqueous saline heteropolysaccharide solutions containing at least 0.5 wt. % of inorganic salts which are stabilized against viscosity loss on heat treatment. The stabilization process comprises preparing an aqueous solution containing heteropolysaccharide and inorganic salts, removing oxygen from the saline solution, heating to a temperature of at least 100.degree. C. in an inert atmosphere, then removing cell debris. The solutions also have improved filterability and are free of cell debris.

Abstract: A method for increasing pressure in geological oil-bearing structures by gas production due to microbial activity comprising adding to a geological oil-bearing structure, a methane producing aneorobic micro-organism, a culture medium and formic acid. The formic acid is converted to carbon dioxide and methane gases resulting in increased pressure in the structures.

Abstract: An aqueous mobility control solution for tertiary oil recovery from saline oil fields comprises from about 200 to 2000 ppm xanthan biopolymer in the form of clean, unreconstituted fermentation broth and from about 20 to 200 ppm of a selected water-soluble polyglycol-based surfactant. A process for tertiary oil recovery which comprises the injection of the mobility control solution into saline oil-bearing subterranian formations is also disclosed.

Abstract: A method and apparatus for treating ground and ground water contaminated with hydrocarbon and halogenated hydrocarbon compounds. Treatment of contaminated water removed from the ground is accomplished by microorganisms which consume the contaminants. Growth of microorganisms is enhanced under controlled conditions by addition of nutrients and gases such as oxygen, nitrogen, carbon dioxide or a combination of these and other gases to the contaminated water. Treated water carrying microorganisms, nutrients and gases is returned for recirculation through the contaminated area of ground to leach out and biodegrade the contaminants deposited in the ground. Microorganism activity is also enhanced in the ground by injection of nutrients and oxygen or other gases into the ground and ground water in the contaminated area.

Abstract: This invention relates to a process for the production of a polysaccharide wherein a microorganism species which produces polysaccharide (preferably in the stationary phase of the growth cycle) is supported on a porous, particulate inert support, the pore size being greater than about 0.5 .mu.m, to form an immobilized cell system, aqueous nutrient medium is passed through the immobilized system, and polysaccharide-containing medium is withdrawn from the system. The invention provides also for the use of the polysaccharide in the displacement of fluid from subsurface formations, and an immobilized cell system for use in the foregoing process.

Abstract: Water-soluble polymers that thicken reversibly in aqueous solution on alteration of the degree of alkalinity are manufactured by treating an aqueous suspension of protein with the enzymes elaborated extracellularly by a species of the genus Pseudomonas. The water soluble polymers resulting therefrom are biodegradable. They are useful for stabilizing emulsions, as flow-control agents in water base paint, and as anti-redeposition agents in laundry detergents. They are particularly useful as coagulants for colloidal suspensions of solids such as the phosphate slimes byproduct of the large scale hydraulic mining of the phosphate deposits. They are also particularly useful as flow control agents in the water flooding process for the recovery of petroleum.

Abstract: Application, for the enhanced oil recovery by means of an aqueous solution, of an agent capable of increasing the viscosity of the solution. Said agent consists of a mixture of a xanthan salt of a trivalent metal, iron or aluminum, with a complexant for the ion of the trivalent metal.

Abstract: A mutant strain of the genus Xanthomonas produces a pyruvate-free biopolymer. This biopolymer and the deacetylated form of this new biopolymer provide mobility control solutions which are especially useful for enhanced oil recovery where high brine applications are involved. The mobility control solutions of the present invention may be made from whole or filtered fermentation broth containing the pyrvuate-free biopolymer or its deacetylated form. Alternatively, the biopolymer or its deacetylated form may be recovered from the broth and the recovered product used to form the desired mobility control solutions.

Abstract: A method for restricting fluid flow in depth outwardly from the bore hole through the medium to high permeable zones of a subterranean reservoir of nonuniform permeability in which there is injected into the reservoir aqueous solutions of a water-soluble polymer and an alkali metal silicate. The injected solutions are either admixed at the surface prior to injection, simultaneously injected or injected sequentially.

Abstract: A method for enhancing the ability of polysaccharides in aqueous solution to flow through a porous medium comprises contacting the polysaccharides with an endoenzyme capable of hydrolyzing at least one of the linkages of the sugar units of the polysaccharides and maintaining the polysaccharides in contact with the enzyme under hydrolysis conditions for a time sufficient to decrease the tendency of the polysaccharides to plug the porous medium yet insufficient to decrease the viscosity of the aqueous polysaccharides by more than 25%. The partially hydrolyzed polysaccharides are useful as thickening agents for flooding water used to recover oil from oil-containing subterranean formations.

Abstract: Disclosed is a novel sulfated biopolymer, a method for synthesizing the sulfated biopolymer and an oil recovery method employing an aqueous fluid containing the material. The sulfated biopolymer is made by reacting polysaccharides with sulfuric acid in the presence of an aliphatic alcohol at a temperature of from 35.degree. to 75.degree. F., in order to avoid degradation of the polymer by the sulfuric acid. The polymer produces a viscous solution which is less prone to increasing viscosities as shear rate is decreased, which makes it especially suitable for use as a viscosifying polymer in a polymer flooding enhanced oil recovery process.

Abstract: A method for increasing pressure in geological oil-bearing structures by gas production due to microbial activity comprising adding to a geological oil-bearing structure, an aneorobic micro-organism (Methanobacterium Termoautotroficum), a culture medium and formic acid. The formic acid is converted to carbon dioxide and methane gases resulting in increased pressure in the structures.