Marathon Oil Company

Hercules Corporation

Other

John S Rhudy

Perry A Argabright

Bruce L Knight

William B Gogarty

Brian L Phillips

Connie L Gibb

An on-site, in-line process and system for recovering oil from oil-bearing subterranean formations which involves the production, modification, dilution and injection of a polymer solution, preferably consisting essentially of an aqueous solution of a partially hydrolyzed polyacrylamide, having injectivity and mobility properties capable of meeting the specific permeability requirements of substantially any subterranean formation to be achieved. The polymer solutions prepared by the process and system can be used as drive fluids for displacing oil (secondary polymer flood) in an oil-bearing formation, as mobility buffers to follow micellar dispersion floods in the conjoint presence of chemical reagents in other chemical floods (e.g., surfactant, caustic, etc.), or they can follow a water flood. The solutions can also be used to promote pipelining of high viscosity crude oil. Irrespective of the use to which the solutions are put, the process and system enable the polymer solutions to be customized, or tailor-make, so to speak, to meet the performance demands of the environment in which they are to be used, whether it be an oil-bearing formation or a pipeline.

Oil recovery process and system

An on-site, in-line process and system for recovering oil from oil-bearing subterranean formations which involves the production, modification, dilution and injection of a polymer solution, preferably consisting essentially of an aqueous solution of a partially hydrolyzed polyacrylamide, having injectivity and mobility properties capable of meeting the specific permeability requirements of substantially any subterranean formation to be achieved. The polymer solutions prepared by the process and system can be used as drive fluids for displacing oil (secondary polymer flood) in an oil-bearing formation, as mobility buffers to follow micellar dispersion floods in the conjoint presence of chemical reagents in other chemical floods (e.g., surfactant, caustic, etc.), or they can follow a water flood. The solutions can also be used to promote pipelining of high viscosity crude oil. Irrespective of the use to which the solutions are put, the process and system enable the polymer solutions to be customized, or tail-made, so to speak, to meet the performance demands of the environment in which they are to be used, whether it be an oil-bearing formation or a pipeline.

An on-site, in-line process and system for recovering oil from oil-bearing subterranean formations which involves the production, modification, dilution and injection of a polymer solution, preferably consisting essentially of an aqueous solution of a partially hydrolyzed polyacrylamide, having injectivity and mobility properties capable of meeting the specific permeability requirements of substantially any subterranean formation to be achieved. The polymer solutions prepared by the process and system can be used as drive fluids for displacing oil (secondary polymer flood) in an oil-bearing formation, as mobility buffers to follow micellar dispersion floods in the conjoint presence of chemical reagents in other chemical floods (e.g., surfactant, caustic, etc.), or they can follow a water flood. The solutions can also be used to promote pipelining of high viscosity crude oil. Irrespective of the use to which the solutions are put, the process and system enable the polymer solutions to be customized, or tailor-made, so to speak, to meet the performance demands of the environment in which they are to be used, whether it be an oil-bearing formation or a pipeline.

Oil recovery process

A method of reducing the fluid flow friction loss of fluid waste materials in the conduits of sanitary sewer systems while at the same time maintaining the solid materials in the fluid in a flowable condition by introducing into a sewer system about 1 to about 10,000 ppm of an aqueous solution of a partially hydrolyzed polyacrylamide polymer having a preselected average molecular weight and molecular weight distribution.

Treatment of sanitary sewer systems

Polymer mobility control agents useful in supplemental oil recovery processes, which give improved reciprocal relative mobilities, are prepared by initiating the polymerization of a monomer containing a vinyl group with a catalyst comprising a persulfate and ferrous ammonium sulfate. The vinyl monomer is an acrylyl, a vinyl cyanide, a styryl and water soluble salts thereof.

Mobility control agent

Drag reduction of fluids containing a water phase, e.g. hydrocarbon-in-water mixture, flowing through a conduit, is reduced by incorporating within the water phase a polymer obtained by radiation-induced polymerization of acrylamide, methacrylamide, acrylic acid, methacrylic acid, alkali metal salts thereof, or mixtures thereof. The polymerization is preferably carried out in 10-60% aqueous monomer solution with gamma radiation. The mixture of monomers, before radiation, preferably contains 25-99% acrylamide and 75-1% sodium acrylate. The polymer preferably shows viscoelastic effects at high concentrations in a solvent. Concentrations of about 1-10,000 ppm of the polymer in the water phase is desired. Examples of fluids useful with this invention include hydrocarbon-in-water and water-in-hydrocarbon slurries, the hydrocarbon is preferably comminuted oil shale or coal, congealed particles of crude oil and/or wax, viscous crude oil, etc.

Use of radiation-induced polymers as friction reducing agents

Plugging of reservoirs with high molecular weight polymers, e.g. partially hydrolyzed polyacrylamide, is overcome by chemically treating a polymer having an excessively high average molecular weight prior to injection into a reservoir with an oxidizing chemical, e.g. sodium hypochlorite, and thereafter incorporating a reducing chemical, e.g., sodium sulfite, to stop degradation of the polymer when a desired lower average molecular weight and flooding characteristics are attained.

Recovery of petroleum with chemically treated high molecular weight

Improved injectivity profiles and/or vertical conformance in flooding heterogeneous formations containing high permeability zones is obtained by injecting an aqueous polyacrylamide solution and an aqueous formaldehyde solution into the formation and allowing the polyacrylamide to react with the formaldehyde in the relatively high permeability zones to form a gel. Thereafter, improved sweep efficiency is realized in displacing hydrocarbon from the lesser permeability zones.

Method of improving injectivity profiles and/or vertical conformance in

The injectivity profile of a heterogeneous formation and/or vertical conformance is improved by injecting an aqueous solution into the formation, the solution containing a polymer obtained as a product of radiation-induced polymerizatin of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in a 10-60% aqueous solution with gamma radiation; the aqueous monomer solution preferably contains 25-99% acrylamide and 1-75% sodium acrylate. Immiscible, miscible, or miscible-like displacing processes can be used in conjunction with this invention.

Injection profiles with radiation induced copolymers

Improved fracturing of subterranean formations with water-based fracturing fluids is obtained by incorporating into an aqueous fracturing fluid (1) a water-soluble, high molecular weight polymer that will crosslink in the presence of chromic ion and (2) controlled amounts of chromic ion to crosslink the polymer to form a gel of desired viscosity. Useful polymers include partially hydrolyzed polyacrylamide and copolymers of acrylamide and sodium acrylate.

Fracturing fluid

Water loss from cement slurries is reduced by incorporating within a cement slurry a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in 10-60% aqueous monomer solution with gamma radiation. The aqueous monomer solution preferably contains 25-99% acrylamide and 75-1% sodium acrylate. The polymer can be present in concentration of about 0.001 to about 3.0 weight percent, based on the aqueous phase of the slurry.

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Littleton, CO, United States of America

John S Rhudy