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US-20260125497-A1 - POLYMER, PREPARATION METHOD THEREFOR AND USE THEREOF

US20260125497A1US 20260125497 A1US20260125497 A1US 20260125497A1US-20260125497-A1

Abstract

A polymer contains a sulfonate group, a benzene ring, and an unsaturated double bond at the same time. The molar ratio of the sulfonate group, the benzene ring, and the unsaturated double bond is 3-8:5-20:10-120. The number average molecular weight of the polymer is 1000-15000 g/mol. The polymer, as a viscosity reducer, has a high resistance to high concentrations of calcium and magnesium ions, a good viscosity reduction effect on super heavy oil, and good natural sedimentation and dehydration properties. It is resistant to viscosity rebound, has good water solubility, and has a simple matching injection process, and is suitable for practical use in oil fields.

Inventors

  • Guangfu Wang
  • Haibo Wang
  • Xi LU
  • Jichao Fang
  • Liansheng Wang
  • Yong Hu
  • Mengtao Li
  • Ping Tang

Assignees

  • CHINA PETROLEUM & CHEMICAL CORPORATION
  • PETROLEUM EXPLORATION & PRODUCTION RESEARCH INSTITUTE

Dates

Publication Date
20260507
Application Date
20231010
Priority Date
20221011

Claims (20)

  1. 1 . A polymer, wherein the polymer contains a sulfonate group, a benzene ring, and an unsaturated double bond at the same time; a molar ratio of the sulfonate group, the unsaturated double bond, and the benzene ring is (3-8):(5-20):(10-120); a number average molecular weight of the polymer is within a range of 1,000-15,000 g/mol.
  2. 2 . The polymer according to claim 1 , wherein the number average molecular weight of the polymer is within a range of 2,000-8,000 g/mol; a molecular weight distribution is within a range of 1.2-2.
  3. 3 . The polymer according to claim 1 , wherein a conjugated large 71 bond is formed between the benzene ring and the unsaturated double bond in the polymer.
  4. 4 . The polymer according to claim 1 , wherein the polymer comprises structure unit A having a structure represented by formula I and structure unit B having a structure represented by formula II: wherein R 1 , R 2 , R 3 in formula I are independently selected from hydrogen, substituted or unsubstituted C 1 -C 6 alkyl, M is an alkali metal element, alkaline earth metal element, or NH 4 + ; R 4 , R 5 , R 6 , R 7 , R 8 , R 9 in formula II are independently selected from hydrogen, substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted aryl, and at least two of R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are substituted or unsubstituted aryl.
  5. 5 . The polymer according to claim 4 , wherein R 1 , R 2 , R 3 in formula I are independently selected from hydrogen, substituted or unsubstituted methyl, substituted or unsubstituted ethyl; R 6 , R 7 , R 8 , R 9 in formula II are independently benzene ring, both R 4 and R 5 are independently selected from hydrogen, substituted or unsubstituted methyl, substituted or unsubstituted ethyl.
  6. 6 . The polymer according to claim 4 , wherein the structure unit A is contained in an amount within a range of 10-50 wt %, and the structure unit B is contained in an amount within a range of 50-90 wt %, based on the total weight of the polymer.
  7. 7 . A method for preparing the polymer comprising: subjecting monomer A and monomer B to an emulsion polymerization reaction in the presence of an initiator, a catalyst, and a surfactant under an anaerobic condition to obtain the polymer; the monomer A contains a sulfonate group, and the monomer B contains a benzene ring and a unsaturated double bond; wherein a molar ratio of the unsaturated double bond and the benzene ring in monomer B is 1:(1-3).
  8. 8 . The method according to claim 7 , wherein the monomer A is used in an amount of 10-30 parts by weight, the monomer B is used in an amount of 10-80 parts by weight, the initiator is used in an amount of 2-10 parts by weight, the catalyst is used in an amount of 1-5 parts by weight, and the surfactant is used in an amount of 1-3 parts by weight.
  9. 9 . The method according to claim 7 , wherein the monomer A is a compound having a structure represented by formula III, and the monomer B is a compound having a structure represented by formula IV; wherein R 1 ′, R 2 ′, R 3 ′ in formula III are independently selected from hydrogen, substituted or unsubstituted C 1 -C 6 alkyl, M is an alkali metal element, alkaline earth metal element, or NH 4 + ; R 4 ′, R 5 ′, R 6 ′, R 7 ′, R 8 ′, R 9 ′ in formula IV are independently selected from hydrogen, substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted aryl, and at least two of R 4 ′, R 5 ′, R 6 ′, R 7 ′, R 8 ′, R 9 ′ are substituted or unsubstituted aryl.
  10. 10 . The method according to claim 8 , wherein the initiator comprises a water-soluble initiator and an oil-soluble initiator.
  11. 11 . The method according to claim 7 , wherein the catalyst is at least one selected from the group consisting of tetramethylethylenediamine, dimethylethylenediamine, acetylacetone, cyclopentadiene, TiCl 4 , TiCl 3 , VOI 3 , or VOCl 3 .
  12. 12 . The method according to claim 7 , wherein the surfactant is at least one selected from the group consisting of Tween 20, Tween 40, Tween 60, polyethylene glycol 200 and peregal O-20.
  13. 13 . The method according to claim 7 , wherein emulsion polymerization reaction conditions comprise a temperature within a range of 80-140° C. and a time of 1-8 h.
  14. 14 . The method according to claim 7 , wherein the method further comprises subjecting the emulsion polymerization reaction to a quenching treatment.
  15. 15 . The method according to claim 14 , wherein the quenching treatment is performed by adding a polymerization inhibitor.
  16. 16 . (canceled)
  17. 17 . A method of using the polymer according to claim 1 as a viscosity reducer.
  18. 18 . The polymer according to claim 4 , wherein R 6 , R 7 , R 8 , and R 9 in formula II are independently benzene rings, both R 4 and R 5 are independently selected from hydrogen, substituted or unsubstituted C 1 -C 6 alkyl, substituted or unsubstituted aryl.
  19. 19 . The polymer according to claim 6 , wherein the structure unit Ais contained in an amount within a range of 16-50 wt %, and the structure unit B is contained in an amount within a range of 50-84 wt %, based on the total weight of the polymer.
  20. 20 . The method according to claim 10 , wherein the water-soluble initiator is at least one selected from the group consisting of 2,2′-azobis[2-methylpropionamidine]dihydrochloride, ammonium persulfate, potassium persulfate, sodium persulfate, and 2,2′-[azobis(1-methylethylidene)]bis[4,5-dihydro-1H-imidazole dihydrochloride; and/or, the oil-soluble initiator is at least one selected from the group consisting of dibenzoyl peroxide, tert-butyl peroxybenzoate, azobisisobutyronitrile, and di-tert-butyl peroxide.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The application claims the benefit of the Chinese Patent Application No. “202211238976.3”, filed on Oct. 11, 2022, the content of which is specifically and entirely incorporated herein by reference. TECHNICAL FIELD The present invention relates to the technical field of oil field development, in particular to a polymer, a preparation method therefor and a use thereof. BACKGROUND ART The thick oil has the characteristics such as high viscosity, high density, poor fluidity, and temperature sensitivity, low content of light components, and high content of colloid and asphaltene. Research has shown that crude oils having a viscosity below 400 mPa·s can be extracted and transported. Therefore, a core problem during the extraction of thick oils is how to effectively reduce viscosity and improve the fluidity of the crude oil. The existing extraction methods for thick oil include the thermal production process and the cold production process, wherein the thermal production process of thick oils requires high energy consumption and high costs; in contrast, the cold production process of thick oils does not need a heating process, it can reduce the viscosity of thick oil by means of the chemical viscosity reducer, an injection of CO2, utilization of microorganisms coupled with the addition of physical fields, thus the extraction process has been widely applied in practice. The representative technologies for reducing the viscosity of thick oil with the market application scale at present are as follows. The wellbore visbreaking process for ultra-thick oil production: it uses a mixture of thin oil and a viscosity reducer for reducing viscosity. However, in light of the large price difference between the thin oil and the thick oil, the process does not allow for the oil recovery with cost-efficiency. Emulsifying ultra-thick oil water-based viscosity reducer: the whole surface activity is greatly improved by taking advantage of the synergistic effect of the complex formulation of surfactants, it is possible to significantly reduce the oil-water interfacial tension, thereby achieving a viscosity reduction effect. However, the viscosity reducer in the method needs to mix with the thick oil for a long time under a high-speed stirring condition to produce the viscosity reduction effect, and the viscosity of the thick oil rebounds obviously after stopping the stirring process and standing still for a long time, thus it has poor effect in practical application. The polyglycerol ester-based thick oil viscosity reducer: it can be used for thick oil with a viscosity between 2,000 mPa·s and 60,000 mPa·s at the temperature of 50° C., and produces the viscosity reduction effect by mixing and stirring at high speed. However, the viscosity reducer merely had a viscosity reduction ratio of 28%-75%, and the viscosity rebounds significantly after stopping the stirring process and standing still. In addition, the currently used cold production viscosity reducers for thick oil impose the operating requirement on the concentration of calcium and magnesium ions in the formation water, their usable range suffers from a large limitation. SUMMARY OF THE INVENTION The present disclosure aims to overcome the defects in the prior art that the thick oil has poor viscosity reduction effect under the reservoir condition of high concentration of calcium and magnesium ions, and the viscosity rebounds significantly after standing still, and discloses a polymer, a preparation method therefor and a use thereof, the polymer contains a sulfonate group, a benzene ring, and an unsaturated double bond at the same time, such that the polymer is not completely packed by the thick oil, and maintain the oil/water interface in an oil-in-water state, and the polymer has a low number average molecular weight, it can improve fluidity and reduce viscosity of the thick oil when added to the thick oil. In order to achieve the above objects, the first aspect of the present invention discloses a polymer comprising a sulfonate group, a benzene ring, and an unsaturated double bond at the same time; a molar ratio of the sulfonate group, the unsaturated double bond, and the benzene ring is (3-8):(5-20):(10-120);a number average molecular weight of the polymer is within a range of 1,000-15,000 g/mol. The second aspect of the present invention discloses a method for preparing the polymer comprising: subjecting monomer A and monomer B to an emulsion polymerization reaction in the presence of an initiator, a catalyst, and a surfactant under an anaerobic condition to obtain the polymer; the monomer A contains a sulfonate group, and the monomer B contains a benzene ring and a unsaturated double bond;wherein the molar ratio of the unsaturated double bond and the benzene ring in monomer B is 1:(1-3). The third aspect of the present invention discloses the polymer produced with the method according to the second aspect. The fourth aspect of the