Search

EP-4212494-B1 - POLYMER HAVING DISPERSING FUNCTION AND USE THEREOF

EP4212494B1EP 4212494 B1EP4212494 B1EP 4212494B1EP-4212494-B1

Inventors

  • MIAO, Xia
  • LIU, JIAN
  • LI, Xiaojiang
  • WU, XUEPENG
  • LIU, Haoya
  • ZHOU, SHIMING
  • WEI, Haoguang
  • YANG, Guangguo
  • WANG, Lishuang
  • WANG, QICHUN
  • WANG, MU
  • WANG, XIAOJING
  • ZENG, MIN

Dates

Publication Date
20260506
Application Date
20210813

Claims (7)

  1. A polymer having a dispersing function consisting of a structural unit (a), a structural unit (b) and a structural unit (c); wherein the structural unit (a) is provided by an unsaturated polyether, the structural unit (b) is provided by an unsaturated carboxylic acid and/or a salt thereof and/or an anhydride thereof, and the structural unit (c) is provided by a silane and/or siloxane comprising a polymerizable group and having no less than five carbon atoms; the molar ratio of the structural unit (a), the structural unit (b) and the structural unit (c) is 1: (1-20): (0.01-0.5); the polymer has a weight average molecular weight of 20,000-90,000g/mol;the unsaturated carboxylic acid has a structure represented by formula (II): in formula (II), each of R 1 , R 2 and R 3 is independently selected from hydrogen, C1-C6 alkyl or -COOH, X is (CH 2 ) n , and n is 0, 1, 2, 3, 4, 5 or 6; the structural unit (c) has a structure represented by formula (I): in formula (I), each of R 1 , R 2 , R 3 , R 1 ' and R 2 ' is independently selected from H or C1-C4 alkyl; R a , R b and R c are each independently selected from H, C1-C4 alkyl or alkoxy, and n is an integer of 5-25.
  2. The polymer of claim 1, wherein the molar ratio of the structural unit (a), the structural unit (b) and the structural unit (c) is 1: (4-12): (0.05-0.3), the polymer has a weight average molecular weight of 25,000-55,000g/mol.
  3. The polymer of claim 1 or 2, wherein in formula (I), each of R 1 , R 2 , R 3 , R 1 ', and R 2 ' is independently selected from H or C1-C2 alkyl; R a , R b and R c are each independently selected from the group consisting of H, methyl, ethyl, methoxy, ethoxy, and n is an integer of 8-18; preferably, the silane and/or silaxane is at least one selected from the group consisting of 7-octenyl trimethoxysilane, vinyl dodecyl trimethoxysilane, vinyl hexadecyl trimethoxysilane, vinyl octadecyl trimethoxysilane.
  4. The polymer of any one of claims 1-3, wherein the polymer has a comb-shaped structure; preferably, the polymer is a random copolymer, and the DSC peak of the polymer is a single peak.
  5. The polymer of any one of claims 1-4, wherein the unsaturated polyether has a structure represented by formula (2): in formula (2), E denotes an alkylene having 2-4 carbon atoms; F denotes an alkylene having 2-4 carbon atoms and different from E; R 4 and R 5 each independently denotes H or an alkyl having 1-5 carbon atoms, preferably methyl; R 6 denotes an alkyl having 1-4 carbon atoms; Y denotes an alkylene having 1-5carbon atoms; p denotes an integer of 0-200, preferably an integer of 20-140; q denotes an integer of 0-200, preferably an integer of 20-140; p+q>10, preferably p+q>40; preferably, the unsaturated polyether is at least one selected from the group consisting of methyl allyl polyoxyethylene ether, methyl allyl polyoxypropylene ether, isopentenylpolyoxyethylene ether and isobutylene polyoxyethylene ether.
  6. The polymer of any one of claims 1-5, wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid and fumaric acid.
  7. Use of the polymer of any one of claims 1-6 in a cement slurry for well cementation, preferably, the use is performed in a well with a high temperature not less than 120°C.

Description

CROSS REFERENCE TO RELATED APPLICARTIONS The present disclosure claims the interest of the China Patent Application No. 202011092106.0, filed on October 13, 2020, entitled "POLYMER HAVING DISPERSING FUNCTION, POLYCARBOXYLIC ACID CEMENT DISPERSANT, PREPARATION METHOD THEREFOR AND USE THEREOF". TECHNICAL FIELD The present disclosure relates to a polymer having a dispersing function and a use in the well cementation with cement. BACKGROUND ART The well cementation operations require the pumping of a cement slurry into the annular space between the casing pipe and the wellbore, the cement slurry to be pumped shall have desirable flowing property, while in the practical operations, especially in the well cementation operations which involve with a high temperature, a high pressure, and complicated well conditions, it is necessary to append a variety of additives or admixtures such as a retarder, a filtrate reducer, a weighting agent, a latex material into the cement slurry to meet the requirements of well cementing, the additives or admixtures often result in the poor fluidity of slurry, such that the slurry can hardly be pumped. Therefore, it is generally necessary to add a dispersant into the cement slurry, such that the cement slurry has a reduced viscosity and an increased flowing property under the condition of fixed water-cement ratio, thereby performing an injection of cement slurry with low velocity and turbulent flow. The dispersants for oil well cement slurry in domestic and foreign countries currently in use are primarily the sulfonated aldehyde ketone condensation polymer dispersants, which have been widely used in oil fields since the 1970s, but the disadvantages of such dispersants have been revealed along with the rapid upgrading of other additives and adjuvants of the oil well cement and increasingly stringent environmental protection standards: 1. the dispersants are not compatible with the novel additives and adjuvants; 2. the dispersants have low dispersion efficiency for the cement slurries added with the complex particles (e.g., latex, rubber particles); and 3. their raw material contains formaldehyde, which is currently subjected to a restrained production condition. At present, the polycarboxylic acid water reducers are commonly used in the construction industry, and the patents of polycarboxylic acid water reducers are focused on the construction industry. Recently, the oil well cementation industry has also attempted to introduce the polycarboxylic acid dispersants to replace the sulfonated aldehyde ketone condensation polymer dispersants. However, the polycarboxylic acid water reducers in the construction industry cannot be directly used in the oil well cementation industry due to the issues such as temperature resistance and compatibility. The polycarboxylic acid dispersants (which are used as the water reducers in the construction industry) for the oil well cementation industry are not widely patented, because the defects cannot be easily solved that the polycarboxylic acid dispersants lack a high temperature resistance and compatibility with the set retarders, water reducers, early strength agents specialized for the oil well cements. The polycarboxylic acid dispersants currently used in foreign countries generally have a temperature resistance below 120°C, and are often required to be used with the matched water reducers. Therefore, there is an urgent need in the industry to prepare a polycarboxylic acid dispersants having a high temperature resistance, high efficiency, environmentally friendly property and desired compatibility to replace the existing sulfonated aldehyde ketone condensation polymer dispersants. CN105754045A discloses a silane coupling agent modified polycarboxylic acid water reducer and a preparation method thereof, wherein all examples mention a temperature upper limit of preparation being 45°C The specific steps are as follows: wherein the raw materials are calculated based on parts by weight: 1) placing 350 parts of polyether macromonomer in a reaction vessel, adding with 5-15 parts of acrylic acid and stirring uniformly, then adding 0.5-5 parts of a double bond-containing silane coupling agent; stirring the solution to a clear state without significant lumping or flaking; wherein the polyether macromonomer is one or more selected from the group consisting of methyl allyl polyoxyethylene ether, isoamyl alcohol polyoxyethylene ether, modified isoamyl alcohol polyoxyethylene ether; 2) dropwise adding the solution obtained in step 1) sequentially under the stirring condition with 2.5-6 parts of an oxidant, 2.5-3.5 parts of an initiator and 20-37 parts of small monomer, the dropwise adding time of the small monomer solution is 1-4 hours; the small monomer is one or more selected from the group consisting of acrylic acid, sodium methallyl sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, itaconic acid, fumaric acid, maleic anhydride; 3) aging the solution obtaine