# US 2014/0190699 A1 · Recovery of Oil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190699 A1 - Document ID: US20140190699A1 - Status: Published application - Kind: A1 - Application number: 14/236,120 - Filed: 2012-07-23 - Published: 2014-07-10 - Earliest claimed: 2011-08-01 - Assignees: Oilflow Solutions Holdings Limited - Inventors: Philip Fletcher; Jeffrey Forsyth; Cory Jaska - Web page: https://patentgrep.com/patent/US20140190699A1 ## CPC - C09K 8/588: characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} - E21B 43/16: Enhanced recovery methods for obtaining hydrocarbons - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A treatment formulation for use in enhanced oil recovery is described which includes a dispersing polymer which may be a partly hydrolyzed polyvinyl alcohol and a displacing polymer which may be a partially hydrolysed polyacrylamide. ## Claims ### Claim 1 A method of recovering oil from a subterranean formation, the method including the step of: (a) contacting the subterranean formation with a treatment formulation comprising a displacing polymer and a dispersing polymer; and (b) collecting oil which has been contacted with said treatment formulation via a production well. ### Claim 2 (depends on 1) A method according to claim 1, wherein said displacing polymer is such that a test formulation comprising 500 ppm of said displacing polymer dissolved in deionized water, in the absence of any other additives, has a viscosity when measured at 25° C. and 1 s−1 in the range 5 cP to 100 cP and the following first relationship applies, when viscosity is measured as aforesaid: Viscosity   of   test   formulation   at   30 ∘  C Viscosity   of   test   formulation   at   20 ∘  C >= 0.6 and the following second relationship applies, when the viscosity is measured as aforesaid: Viscosity   of   test   formulation   at   80 ∘  C Viscosity   of   test   formulation   at   20 ∘  C >= 0.10 ### Claim 3 (depends on 1) A method according to claim 1, wherein the viscosity of the treatment formulation divided by the viscosity of a formulation that is the same as said treatment formulation except that it does not include the dispersing polymer, when the viscosities are measured at 25° C. and 1 s−1, is in the range 0.6 to 1.3. ### Claim 4 (depends on 1) A method according to claim 1, wherein said displacing polymer has a molecular weight of at least 200,000 Daltons and a molecular weight of less than 35,000,000 Daltons. ### Claim 5 (depends on 1) A method according to claim 1, wherein said displacing polymer is selected from poly(vinylalcohol), acrylic acid-based, acrylamide-based and vinylpyridine-based polymers, poly(methylvinylether), polyvinylpyrrolidone, polyethylene oxide, cellulose, polysaccharides, biopolymers, scleroglucan, xanthan and derivatives of the aforesaid. ### Claim 6 (depends on 1) A method according to claim 1, wherein said displacing polymer includes at least two different repeat units, wherein said at least two different repeat units include functional groups selected from amide, carboxy, hydroxy and ether groups. ### Claim 7 (depends on 1) A method according to claim 1, wherein said displacing polymer includes a repeat unit which includes an acrylamide of formula ### Claim 8 (depends on 7) A method according to claim 7, wherein said displacing polymer includes a repeat unit of formula I in combination with a repeat unit comprising a moiety wherein the O* moiety is an O− moiety or is covalently bonded to another atom or group. ### Claim 9 (depends on 7) A method according to claim 7, wherein said displacing polymer includes a repeat unit of formula I in combination with a repeat unit comprising a moiety wherein R1 and R2 are independently selected from a hydrogen atom and an optionally-substituted alkyl group. ### Claim 10 (depends on 9) A method according to claim 9, wherein said moiety III is of formula wherein p is an integer in the range 0 to 10; or said moiety III is of formula ### Claim 11 (depends on 1) A method according to claim 1, wherein said displacing polymer is a hydrophobically modified polyacrylamide or an acrylamidomethyl propane sulphonate (AMPS). ### Claim 12 (depends on 1) A method according to claim 1, wherein said displacing polymer is of formula wherein m, n and w represent the average number of respective repeat units and p is an integer in the range 0 to 10; or of formula ### Claim 13 (depends on 1) A method according to claim 1, wherein said treatment formulation includes less than 8000 ppm and at least 25 ppm of said displacing polymer. ### Claim 14 (canceled) ### Claim 15 (depends on 1) A method according to claim 1, wherein an oil dispersion comprising oil from the subterranean formation and an aqueous formulation of dispersing polymer, containing 5000 ppm of dispersing polymer, at an oil:aqueous formulation ratio of 70:30, have the following characteristics at 25° C.: viscosity, at a shear rate of 1 s−1, of less than 4000 cP; pseudoplasticity over the shear rate range 1 s−1 to 100 s−1; viscosity, at a shear rate of 100 s−1, of no more than 600 cP. ### Claim 16 (canceled) ### Claim 17 (depends on 1) A method according to claim 1, wherein said dispersing polymer includes, on average, at least 10 —O— moieties pendent from a polymeric backbone. ### Claim 18 (depends on 1) A method according to claim 1, wherein said dispersing polymer includes a moiety: ### Claim 19 (canceled) ### Claim 20 (canceled) ### Claim 21 (depends on 18) A method according to claim 18, wherein the free bond to the oxygen atom in moiety VIII is bonded to a group R10, wherein moiety —O—R10 is an hydroxyl or acetate group. ### Claim 22 (canceled) ### Claim 23 (canceled) ### Claim 24 (depends on 1) A method according to claim 1, wherein the dispersing polymer includes acetate groups and hydroxyl groups and the ratio of the number of acetate groups to the number of hydroxyl groups in said dispersing polymer is in the range 0.06 to 0.3. ### Claim 25 (depends on 18) A method according to claim 18, wherein each free bond to the oxygen atoms in —O— moieties pendent from the polymeric backbone in said dispersing polymer is of formula —O—R10 wherein each group —OR10 is selected from hydroxyl and acetate. ### Claim 26 (depends on 1) A method according to claim 1, wherein said dispersing polymer comprises at least 70 mole % of vinylalcohol repeat units and 30 mole % or less of vinylacetate repeat units. ### Claim 27 (depends on 1) A method according claim 1, wherein said dispersing polymer comprises 80 to 95% hydrolysed polyvinylalcohol. ### Claim 28 (depends on 1) A method according to claim 1, wherein the weight average molecular weight of said dispersing polymer is in the range 5,000 to 50,000 and/or the viscosity of a 4 wt % aqueous solution of the dispersing polymer at 20° C. is in the range 2 to 4 cP. ### Claim 29 (canceled) ### Claim 30 (depends on 1) A method according to claim 1, wherein said treatment formulation includes: 100 ppm to 30000 ppm displacing polymer 500 ppm to 10000 ppm dispersing polymer. ### Claim 31 (depends on 1) A method according to claim 1, wherein said displacing polymer includes an acrylamide repeat unit and said dispersing polymer includes vinylalcohol and vinylacetate repeat units. ### Claim 32 (canceled) ### Claim 33 (depends on 1) A method according to claim 1, wherein the treatment formulation includes less than 0.1 wt % of a surfactant. ### Claim 34 A treatment formulation comprising a displacing polymer, a dispersing polymer and water wherein said displacing polymer includes an acrylamide repeat unit and said dispersing polymer includes vinylalcohol and vinylacetate repeat units, said treatment formulation includes: 100 ppm to 30000 ppm displacing polymer 500 ppm to 10000 ppm dispersing polymer. ### Claim 35 (depends on 34) Apparatus for use in recovering oil from a subterranean formation, the apparatus comprising: (i) means containing a treatment formulation as claimed in claim 34; (ii) means for delivering said treatment formulation to a subterranean formation so that said treatment formulation contacts the subterranean formation; (iii) means for collecting oil which has been contacted with said treatment formulation. ### Claim 36 (depends on 1) A method according to claim 1, wherein said displacing polymer has a molecular weight of at least 200,000 Daltons and a molecular weight of less than 35,000,000 Daltons, said displacing polymer includes an acrylamide repeat unit and said dispersing polymer comprises 80 to 95% hydrolysed polyvinylalcohol, wherein said treatment formulation includes: 100 ppm to 30000 ppm displacing polymer 500 ppm to 10000 ppm dispersing polymer.