Weak gel system for chemical enhanced oil recovery

Patent metadata

Field	Value
Publication number	US-2017145292-A1
Application number	US-201615360148-A
Country	US
Kind code	A1
Filing date	Nov 23, 2016
Priority date	Nov 23, 2015
Publication date	May 25, 2017
Grant date	—

Abstract

Method are provided for treating a wellbore or subterranean hydrocarbon-bearing formation to increase hydrocarbon recovery from the formation by in-depth mobility control and/or fluid diversion conformance by introducing a water soluble acrylamide polymer and a non-metallic organic crosslinking agent, or a crosslinkable acrylamide polymer, into an injection fluid entering the wellbore or the formation.

First claim

What is claimed is:

1 . A method of treating a wellbore or subterranean hydrocarbon-bearing formation to increase hydrocarbon recovery from the formation, the method comprising:
introducing either a water soluble acrylamide polymer and a non-metallic organic crosslinking agent, or a crosslinkable acrylamide polymer, into an injection fluid entering the wellbore or the formation; wherein the acrylamide polymer and the crosslinking agent or the crosslinkable acrylamide polymer form a flowable crosslinked polymer in the presence of the injection fluid flowing within the formation and the flowable crosslinked polymer pushes the hydrocarbon out of the formation while the flowable crosslinked polymer continues to flow through the formation; the crosslinking agent comprising a polymeric polyamine which is either (i) a reaction product of a polymerization mixture comprised of at least one monomer of Formulae I, II, or III, or a salt thereof; or (ii) comprised of at least one structural unit of Formulae IA, IIA, IIIA, IIIB or IVB, wherein Formulae I, II, III, IA, IIA, IIIA, IIIB and IVA have the following structures:

wherein:
R 1 is each independently hydrogen, a protecting group, or alkyl; and
R 2 R 3 , R 4 , R 5 , R 6 and R 7 are each independently hydrogen, alkyl, or alkoxylalkyl; and
the crosslinkable acrylamide polymer comprising a reaction product of a polymerization mixture comprised of at least one acrylamide monomer and at least one monomer of the Formula I, II or III, or a salt thereof.

2 . A method of increasing the sweep efficiency of a fluid flood of a subterranean hydrocarbon-bearing formation to enhance hydrocarbon recovery from the formation, the method comprising:
introducing either a water soluble acrylamide polymer and a non-metallic organic crosslinking agent, or a crosslinkable acrylamide polymer, into an injection fluid entering a wellbore or the formation to form a crosslinked polymer in a high permeability zone existing within the formation; discontinuing hydrocarbon production from the formation being treated for a time period sufficient to allow the viscosity of the crosslinked polymer within the high permeability zone to increase so that the crosslinked polymer remains fixed within the high permeability zone to divert fluid flow into unswept zones of the formation; after the discontinuation step, introducing injection fluid into the formation being treated to flood the formation, mobilize the hydrocarbon and form a flood fluid; and removing the flood fluid containing the mobilized hydrocarbon from the well as a produced fluid, wherein the crosslinking agent comprises a polymeric polyamine which is either (i) a reaction product of a polymerization mixture comprised of at least one monomer of Formulae I, II, or III, or a salt thereof; or (ii) comprised of at least one structural unit of Formulae IA, IIA, IIIA, IIIB or IVA, wherein Formulae I, II, III, IA, IIA, IIIA, IIIB and IVA have the following structures:

wherein:
R 1 is hydrogen, a protecting group, or alkyl; and
R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each independently hydrogen, alkyl, or alkoxylalkyl; and
the crosslinkable acrylamide polymer comprising a reaction product of a polymerization mixture comprised of at least one acrylamide monomer and at least one monomer of the Formula I, II or III or a salt thereof.

3 . The method of claim 1 , wherein the water soluble acrylamide polymer and the non-metallic organic crosslinking agent are introduced into the injection fluid.

4 . The method of claim 3 , wherein the acrylamide polymer and crosslinking agent are separately introduced into the injection fluid.

5 . The method of claim 3 , or wherein the acrylamide polymer has a molecular weight of from about 0.05 to about 25 megadaltons (“MDa”) or from about 5,000 Daltons to about 25 MDa.

6 . (canceled)

7 . The method of claim 5 , wherein the crosslinking agent has a molecular weight of from about 0.1 to about 1.5 MDa.

8 . The method of claim 3 , wherein the weight ratio of the acrylamide polymer to the crosslinking agent ranges from about 100:1 to about 1:100 or from about 2:1 to about 60:1.

9 . (canceled)

10 . The method of claim 3 , wherein the acrylamide polymer comprises polyacrylamide or partially hydrolyzed polyacrylamide containing up to about 40 mole percent degree of hydrolysis.

11 . The method of claim 3 , wherein the acrylamide polymer comprises either; an anionic co-polymer of acrylamide and up to about 40 mole % of an acrylic acid; an anionic co-polymer of acrylamide and up to about 40 mole % of 2-acrylamido-2-methylpropane sulfonic acid (“AMPS”); an anionic terpolymer of acrylamide and up to about 40 mole % of a combination of acrylic acid and AMPS; a terpolymer of acrylamide and up to about 40 mole % of a combination of AMPS and N-vinylpyrrolidone (“NVP”); or a terpolymer of acrylamide and up to about 40 mole % of a combination of t-butyl-acrylate and NVP.

12 .- 15 . (canceled)

16 . The method of claim 1 , wherein the water soluble acrylamide polymer concentration is from about 200 to about 2,000 ppm.

17 . The method of claim 2 , wherein the water soluble acrylamide polymer concentration is greater than 2,000 ppm.

18 . The method of claim 1 , wherein the crosslinking agent is a polyamine comprising a homopolymer or copolymer of a dialkylamine.

19 . The method of claim 18 , wherein either: the polyamine comprises a homopolymer of diallylamine; the polyamine polymer comprises a copolymer of diallylamine with an acrylamide or an acrylic acid, or a terpolymer of diallylamine with an acrylamide and an acrylic acid; or the polyamine polymer comprises a copolymer of diallylamine with AMPS or NVP, or a terpolymer of diallylamine with AMPS and NVP.

20 .- 22 . (canceled)

23 . The method of claim 1 , wherein the crosslinking agent concentration is from about 5 to about 500 ppm.

24 . The method of claim 3 , wherein during the enhanced hydrocarbon recovery operation, the water soluble acrylamide polymer and the crosslinking agent are continuously added into the injection fluid entering the wellbore or the formation; the water soluble acrylamide polymer and the crosslinking agent are intermittently added into the injection fluid entering the wellbore or the formation; the water soluble acrylamide polymer is intermittently added into the injection fluid entering the wellbore or the formation, and the crosslinking agent is continuously added into the injection fluid entering the wellbore or the formation; or the crosslinking agent is intermittently added into the injection fluid entering the wellbore or the formation, and the water soluble acrylamide polymer is continuously added into the injection fluid entering the wellbore or the formation.

25 .- 27 . (canceled)

28 . The method of claim 1 , wherein the crosslinkable acrylamide polymer is introduced into the injection fluid.

29 . The method of claim 28 , wherein the crosslinkable acrylamide polymer comprises the reaction product of the polymerization mixture comprised of the acrylamide monomer and diallylamine.

30 . The method of claim 28 , wherein the crosslinkable acrylamide polymer is introduced into the injection

Assignees

• Ecolab Usa Inc

Inventors

• Szalai Michael L
• Liu Mei
• Chang Kin-Tai

Classifications

• E21B43/20

  Displacing by water · CPC title

• C09K8/588 Primary

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title

• C09K8/512

  containing cross-linking agents · CPC title

• C09K8/5083

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title