NOVEL FORMULATIONS OF WATER-SOLUBLE POLYMERS AND STABILIZING ADDITIVES FOR INJECTING A SINGLE COMPOUND USEABLE IN INJECTION FLUIDS FOR CHEMICAL ENHANCED OIL RECOVERY

• US 20120058922A1
• Filed: 06/12/2009
• Published: 03/08/2012
• Est. Priority Date: 05/18/2009
• Status: Active Grant

• Current Assignee: SPCM SA
• Original Assignee: SPCM SA
• Inventors: Gaillard, Nicolas, Favero, Cédrick, Giovannetti, Bruno
• Granted Patent: US 9,469,805 B2
• Time in Patent Office: Days
• US Class Current: 507/226
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 220/585 and containing other heteroatoms, e.g. 2-acrylamido-2-methylpropane sulfonic acid [AMPS]
• CPC Class Codes: C08F 226/08 N-Vinyl-pyrrolidine
• CPC Class Codes: C08K 5/005 Stabilisers against oxidation, heat, light, ozone
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: C09K 8/588 characterised by the use of specific polymers polymeric surfactants C09K8/584

Abstract

Composition based on anionic polymers or water-soluble amphoteric (co)polymers suitable for viscosifying the injection fluids for oil recovery, characterized in that, before dilution with the injection fluid, it further contains at least 3 stabilizing agents selected from the group comprising oxygen reducing agents, precipitating agents, free radical scavengers, complexing agents and sacrificial agents, the said stabilizing agent being suitable for preventing the chemical degradation of the polymer once the polymer is introduced into the injection fluid.

Claims

1. Composition based on anionic polymers or water-soluble amphoteric (co)polymers suitable for viscosifying the injection fluids for oil recovery, characterized in that, before dilution with the injection fluid, it further contains at least three stabilizing agents selected from the group comprising oxygen reducing agents, precipitating agents, free radical scavengers, complexing agents and sacrificial agents, the said stabilizing agent being suitable for preventing the chemical degradation of the polymer once the polymer is introduced into the injection fluid.

2. Composition according to claim 1, characterized in that it contains two different stabilizing agents selected from the group comprising the free radical scavengers and a third stabilizing agent different from the first two and selected indifferently from the group comprising the free radical scavengers, complexing agents, sacrificial agents, oxygen scavenging agents or precipitating agents.

3. Composition according to claim 1, characterized in that it contains a first stabilizing agent selected from the group comprising free radical scavengers, a second stabilizing agent selected from the group comprising oxygen reducing agents and a third stabilizing agent different from the first two and selected indifferently from the group comprising free radical scavengers, complexing agents, sacrificial agents, oxygen reducing agents or precipitating agents.

4. Composition according to claim 1, characterized in that the free radical scavengers are selected from the group comprising diethyl thiourea, dimethyl thiourea, mercaptobenzothiazole and mercaptobenzoimidazole.

5. Composition according to claim 1, characterized in that the oxygen reducing agents are selected from the group comprising sulphites bisulphites, metabisulphites, dithionite, hydrazine and derivatives thereof, carbohydrazides, sodium erythorbate.

6. Composition according to claim 1, characterized in that the sacrificial agents are selected from the group comprising glycerol, propylene glycol, trimethyleneglycol, isopropanol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2,4-butanetriol, pentaerythritol (PETA), trimethylolethane, neopentylglycol, 1,2-pentanediol, 2,4-pentanediol, 2,3-pentanediol, trimethylolpropane, 1,5-pentanediol, polyvinyl alcohol partially or totally hydrolyzed.

7. Composition according to claim 1, characterized in that the complexing agents are selected from the group comprising polyacetates and polycarboxylates, polyaspartates, polyphosphates and polyphosphonates, polysuccinates, ethylene-diamine-tetraacetic acid (EDTA), Hepta sodium salt of diethylene triamine penta (methylene phosphonic acid) (DTPMP•

Na7), maleic acid, nitrilotriacetic acid (NTA), oxalic acid.

8. Composition according to claim 1, characterized in that the precipitating agents are selected from the group comprising hydroxides, carboxylates, carbonates, arsenates, cyanurates, phosphorus derivatives or sulphur derivatives.

9. Composition according to claim 1, characterized in that the polymer used contains:

a) at least one monomer selected from non-ionic monomers based on an acrylamide, acrylic, vinyl, allyl or maleic backbone and having a polar non-ionic side group,

b) and optionally one or more ionic monomers selected from the group comprising anionic monomers based on an acrylamide, acrylic, vinyl, allyl or maleic backbone and, having a carboxylic function, a sulphonic acid function;

cationic monomers based on acrylamide, acrylic, vinyl, allyl or maleic having an amine or quaternary ammonium function,

Optionally combined with

c) a hydrophobic monomer based on an acrylamide, acrylic, vinyl, allyl or maleic backbone, having a side hydrophobic function selected from the group comprising derivatives of acrylamide, N,N-dialkylacrylamides, derivatives of acrylic acid, vinyl monomers,

d) and a branching/crosslinking agent selected from the group comprising methylene bisacrylamide (MBA), ethylene glycol diacrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate or methacrylate, triallylamine, formaldehyde, glyoxal, compounds of the glycidylether type or epoxies,

e) and a surfactant monomer based on an acrylamide, acrylic, vinyl, allyl or maleic backbone and, having a structure bearing both hydrophilic and hydrophobic functions.

10. Composition according to claim 1, characterized in that it is in the form of a powder, bead, a reverse emulsion or solution.

11. Composition according to claim 1, characterized in that it contains at least 30% by weight of polymer, preferably at least 50% by weight of polymer.

12. Method for offshore or onshore enhanced oil recovery, consisting in injecting a fluid into the reservoir, the fluid being previously made viscous by means of a water-soluble polymer, characterized in that the polymer is in the form of the composition according to claim 1.

13. Method according to claim 12, characterized in that the composition is injected in a concentration lower than 10 g/l.