Marathon Oil Company

Wayne E Luetzelschwab

Mark A Plummer

Perry A Argabright

Donald E Schroeder, Jr

Carle C Zimmerman, Jr

Henry J Pietrzak

Kent W Robinson

John R Coleman, Jr

A process for preparing aqueous polymer solutions wherein a section of a fluid conduit through which a stream of liquid polymer product flows contains spaced static mixers. Heated water from a heat exchanger surrounding the section of conduit containing the mixers is introduced to a reactor to function as reaction water. The static mixers are spaced apart enough to enable the heat exchanger to sufficiently cool the liquid polymer product. The mixers function to mix other liquid agents with the liquid polymer product and to mix together warmer and cooler quantities of liquids encountered in the conduit.

Preparation and cooling of aqueous polymer solution

A low viscosity liquid, such as a monomer, is mixed with a gel, such as a concentrated polymer in gel form. The gel and monomer flow through a cylinder containing spaced rotating discs and stationary discs mounted between the rotating discs. The rotating discs are rotated slowly, at speeds in the range of 10 to 100 rpm, so as not to degrade the polymer. The discs contain a number of apertures through which the gel and liquid flow, breaking the gel down into small particles and increasing the gel surface area exposed to the liquid, thus increasing the rate of diffusion of the low viscosity liquid into the gel.

Apparatus and method for mixing a gel and liquid

A polymer solution makeup water containing hydrogen sulfide is pretreated with an oxygenating agent to convert the hydrogen sulfide to an inert compound. The treated water is then mixed with an acrylamide polymer to form a stable polymer solution for oil recovery applications.

Oil recovery process using a treated polymer solution

Apparatus and method for the continuous preparation of dilute solutions of water soluble polymers, and especially to a closed, on-site arrangement for the continuous production of partially hydrolyzed polyacrylamide solutions for use in the secondary and tertiary recovery of oil from subterranean, oil-bearing reservoirs. The apparatus, in its preferred form, comprises an in-line system which includes a polymerization reactor, a hydrolysis reactor and a diluter. The dimensions of the reactors are such that the reactions taking place therein will go to completion as the reaction mixtures move from the inlet to the outlet of the reactors. Drag means advantageously are positioned in the reactors to control the flow rate of the reaction mixtures and to promote intermixing of the reactants. The diluter of the system incorporates a plurality of polymer dispersing stations which act to progressively increase the water absorbing surface area of the polymer as the polymer solution passes through each station. The diluted end product is characterized by its ability to meet the performance demands of substantially any oil-bearing formation.

Apparatus and method for the continuous production of aqueous polymer

Apparatus, and method, for controlling the flow of dilute solutions of polymers such as dilute aqueous solutions of partially hydrolyzed polyacrylamides without causing any significant degradation of the polymer comprising the solutions. In one embodiment, the apparatus comprises a plurality of fixed restrictions connected in series with nipples having a larger internal diameter than the fixed restrictions. In another embodiment, the apparatus comprises at least one fixed restriction in communication with a flow control valve such as a needle valve.

Flow control apparatus and method

A water-soluble inorganic non-crosslinking salt is incorporated in an aqueous gel-like solution of a water-soluble uncrosslinked polymer at an initial higher polymer concentration. The salt accelerates the dilution of the polymer solution with an aqueous diluent to an aqueous polymer solution at a predetermined lower polymer concentration. The gel-like polymer solution is diluted without substantially degrading the polymer so that it retains desirable properties for use in a hydrocarbon recovery process.

Method of diluting a concentrated polymer solution for use in a

Apparatus, and method, for diluting polymer solutions of a known concentration to a preselected lower concentration without any concomitant degradation or thinning of the polymer comprising the solution. The apparatus comprises an elongated chamber desirably in the form of a cylinder or tube having polymer solution dispersing stations arranged in spaced relation therealong. The dispersing stations comprise at least one perforated plate or screen. The perforations in the plates or screens diminish in size as the polymer solution and a diluent for the solution advance in the direction of the outlet or discharge end of the chamber. Flow control means desirably are positioned between one, or more, of the dispersing stations. In accordance with the method aspects of the invention, a polymer solution of a known concentration is successively dispersed in a manner to enable increasing amounts of a diluent to be taken-up or absorbed by the polymer solution until the concentration of the polymer in the final solution attains a predetermined lower concentration.

Dilution apparatus and method

A process for producing an aqueous partially hydrolyzed polyacrylamide solution employed to recover oil from a subterranean oil-bearing formation. The properties of viscosity and screen factor for an aqueous polymer solution are correlated to the polymerization reaction parameters. Values of the parameters are selected which correlate to the specific predetermined polymer properties capable of meeting the performance demands of the formation and the aqueous partially hydrolyzed polyacrylamide solution is produced at the selected values of the reaction parameters.

Production of a polyacrylamide solution used in an oil recovery process

Flow control of a diluted polymer solution stream is effected by utilizing positive-displacement flow devices such as hydraulic pumps and motors to withdraw energy from the stream and to use it to control the rate of flow of the stream in a manner to prevent, or minimize, degradation of the polymer comprising the solution. Flow control is obtained by varying the nature and amount of energy withdrawn, by means of an air compressor in one form of the system.

Polymer flow control apparatus

A method for preparing dilute aqueous polymer solutions, especially dilute aqueous partially hydrolyzed polyacrylamide solutions, for use in secondary and tertiary oil recovery processes. The method comprises producing a concentrated polymer solution in a polymerization reactor and diluting the resulting gel-like, relatively high concentration polymer solution to obtain a free-flowing, relatively low concentration polymer solution by means of a staged dilution process. In each stage, an aqueous diluent is combined with the polymer solution to produce a nonuniform mixture which is maintained in a vessel in a quiescent state until the mixture becomes uniform. The stages are repeated as many times as necessary until the free-flowing, relatively low concentration polymer solution is obtained.

Method for preparing dilute polymer solutions

A method for the on-site continuous preparation of aqueous solutions of polymers, especially aqueous solutions of partially hydrolyzed polyacrylamides, for use in secondary and tertiary oil recovery processes. The method utilizes an apparatus comprised of a polymerization reactor and a post polymerization reactor. Successive batches of an initiated reaction mixture are sequentially fed into the polymerization reactor in discrete volumes. The volumes are moved through the polymerization reactor at a rate such that when a volume reaches the outlet of the polymerization reactor, the reaction will have gone to substantial completion. The resulting polymer solution is withdrawn from the polymerization reactor and continuously conveyed to the post polymerization reactor. Enroute dilution water and a polymer modifying agent are continuously introduced into the polymer solution to form a second reaction mixture. The second reaction mixture is continuously moved through the post polymerization reactor at a flow rate such that the reaction will be substantially complete when the mixture reaches the reactor outlet.

Method for preparing polymer solutions

Apparatus for the on-site, continuous preparation of aqueous solutions of polymers, especially aqueous solutions of partially hydrolyzed polyacrylamides, for use in secondary and tertiary oil recovery operations. The apparatus comprises a polymerization reactor and a post reactor. Successive batches of a pre-prepared reaction mixture are continuously fed into the polymerization reaction in a manner to form zones or layers in the reactor, each zone or layer comprising a reaction mixture which has reached a different stage or level of completion of the reaction than the zone or layer below and above it. The zones or layers are continuously moved through the polymerization reactor at a rate such that when a zone or layer reaches the outlet of the polymerization reactor, the reaction will have gone to substantial completion. The zones or layers are continuously conveyed from the polymerization reactor to the post reactor. Enroute to the post reactor, a polymer modifying agent is continuously introduced into the zones or layers from the polymerization reactor. A second reaction mixture is established in the post reactor in which the extent of the completeness of the reaction taking place in the post reactor varies from the inlet to the outlet thereof. The second reaction mixture is continuously moved through the post reactor at a flow rate such that the reaction will be substantially complete when the outlet of the post reactor is reached.

Apparatus for preparing polymer solutions

Apparatus, and method, for controlling the flow of dilute solutions of polymers such as dilute aqueous solutions of partially hydrolyzed polyacrylamides without causing any significant degradation of the polymer comprising the solutions. In one embodiment, the apparatus comprises a needle valve positioned in a conduit for transporting polymer solutions, and across which a fluid pressure differential exists. In another embodiment, the apparatus comprises a self-adjusting flow regulator which incorporates a tapered, or pointed, throttle carried on a reciprocatable piston.

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Littleton, CO, United States of America

Wayne E Luetzelschwab