Gelling composition, alkali-activated cementing material and application

Abstract

The invention provides a gelling composition, an alkali-activated gelling material and application. The gelling composition comprises a gelling material, an alkali activator and a retarder, wherein the retarder comprises any one or a combination of more than two of a homopolymer of a monomer A and a copolymer of the monomer A and a monomer B; the monomer A comprises an unsaturated carboxylic acid monomer; the monomer B comprises a polymerizable monomer containing a carbon-carbon double bond. The gelling composition provided by the invention can prolong the coagulation time of the alkali-activated gelling material on the premise of ensuring excellent mechanical properties. The invention also provides application of the polycarboxylic acid high-molecular compound in oil and gas well cementing cement.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to the design of a cementitious composition, an alkali-activated cementitious material, and its application. Background Technology

[0002] Alkali-activated materials are a new type of low-carbon cementitious material, typically prepared by activating the reaction of aluminosilicate glass in fly ash, slag, etc., using strong alkalis such as sodium hydroxide and potassium hydroxide, or weak alkalis such as sodium carbonate and sodium silicate. However, alkali-activated materials have a rapid hydration reaction rate and a relatively short setting time. Typical concrete construction usually requires a setting time of at least 8 hours to meet the needs of concrete transportation and pouring. The application of alkali-activated materials in concrete construction faces engineering challenges due to their excessively rapid reaction rate and short setting time. Furthermore, due to their excellent mechanical properties and durability, alkali-activated cementitious materials have significant advantages as cement sheaths for oilfield cementing operations in high-temperature, highly corrosive environments (such as those with acidic corrosion like CO2 and H2S). However, cementing engineering places high demands on the workability of cement slurry, including good flowability and long-term flow retention, suitable thickening time, good slurry stability, and low pressure loss. Therefore, when using alkali-activated cementitious materials as cement slurry in oilfields, it is urgent to overcome the engineering challenges of excessively rapid alkali activation reactions, especially the violent reactions at high temperatures, poor flowability, and short thickening time.

[0003] Retarders are admixtures that can significantly delay the hydration of cementitious materials and prolong the setting time. They can adjust the setting and hardening process of cementitious materials or concrete as needed to adapt to different construction requirements. Although there are many types of retarders and a wealth of related research, existing retarders are mainly applicable to silicate cementitious material systems, including borax or other boron-containing inorganic substances, phosphates, sodium gluconate, zinc salts, barium salts, etc. Summary of the Invention

[0004] This invention provides a gelling composition that can be used to prepare alkali-activated gelling materials with a long setting time. Furthermore, this invention also provides new uses for polycarboxylic acid polymers.

[0005] On one hand, the present invention provides a gelling composition comprising a gelling material, an alkali activator, and a retarder; wherein the retarder comprises any one or more combinations of a homopolymer of monomer A, a copolymer of monomer A and monomer B; monomer A comprises an unsaturated carboxylic acid monomer, which may contain one or more functional groups selected from ester (-COO-), amide (-CO-NH-), and hydroxyl (-OH), or may not contain these functional groups; monomer B comprises a polymerizable monomer containing a carbon-carbon double bond; monomer B may contain one or more functional groups selected from quaternary ammonium cations, sulfonate anions, acid anhydrides, sulfonic acid groups, ester groups, -C(=O)-OC(=O)-, amide groups, hydroxyl groups, amino groups, amine groups, ether bonds, phosphonic acid groups, and phosphonate ester groups, or may not contain these functional groups; furthermore, monomer B does not contain substituents, but may contain one or more substituents selected from heterocyclic groups, aryl groups, and heteroaryl groups.

[0006] According to some embodiments of the present invention, monomer A comprises one or more of C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids. In some embodiments, the C3-C10 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C10 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C10 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0007] According to some embodiments of the present invention, monomer A comprises one or more of C3-C8 monounsaturated carboxylic acids, C4-C8 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids. In some embodiments, the C3-C8 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C8 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C8 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0008] According to some embodiments of the present invention, monomer A comprises one or more of C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids. In some embodiments, the C3-C6 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C6 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C8 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0009] In this invention, examples of monomer A include, but are not limited to, one or more combinations of the following monomers: acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, medaconic acid, crotonic acid, citraconic acid, acryloyloxypropionic acid, methacryloyloxypropionic acid, vinylacetic acid, monomethyl itaconic acid, monomethyl fumarate, monobutyl fumarate, acrylamide glycolic acid, methacrylamide glycolic acid, etc.

[0010] According to some embodiments of the present invention, monomer A comprises a C3-C6 monounsaturated carboxylic acid. According to some embodiments of the present invention, monomer A comprises a C3-C4 monounsaturated carboxylic acid. In some embodiments, monomer A comprises one or more of acrylic acid and methacrylic acid. In some embodiments, monomer A comprises acrylic acid.

[0011] According to some embodiments of the present invention, the monomer B comprises C3-C10 unsaturated chain anhydrides, C3-C10 unsaturated cyclic anhydrides, C2-C10 unsaturated sulfonic acids, C3-C10 unsaturated fatty amides containing sulfonic acid functional groups, C3-C10 unsaturated sulfonic acids substituted with C6-C15 aryl groups (e.g., phenyl) or their salts, C3-C10 unsaturated fatty acid esters containing sulfonic acid functional groups or their salts, C3-C10 chain or cyclic unsaturated fatty amides, hydroxyl-containing C3-C10 unsaturated fatty amides, C3-C10 unsaturated fatty acid esters containing amino functional groups (e.g., dimethylamino, diethylamino, etc.), C3-C10 unsaturated fatty acid esters, and hydroxyl-containing C3-C10 unsaturated fatty acids. Ester, C3-C10 unsaturated fatty acid esters substituted with C1-C12 heterocyclic groups, C3-C10 unsaturated fatty acid esters containing ether bonds, C3-C10 unsaturated fatty acid esters containing quaternary ammonium salt cations, C3-C10 unsaturated fatty amides containing quaternary ammonium salt cations, C2-C10 olefin monomers containing quaternary ammonium salt cations, C3-C10 unsaturated ether monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 aromatic heterocyclic groups, C2-C10 olefin monomers containing imidazole cations, C2-C10 unsaturated phosphonic acids, and C3-C10 unsaturated phosphonate esters, or one or more of these.

[0012] In this invention, the substituent "C6-C15 aryl" in monomer B is preferably C6-C12 aryl, more preferably phenyl. The "amino functional group" in monomer B is preferably -NR1R2, wherein R1 and R2 are independently C1-C6 alkyl groups, preferably independently C1-C4 alkyl groups, such as methyl, ethyl, propyl, isopropyl, etc.; the amino functional group is more preferably dimethylamino or diethylamino. The substituent "C1-C12 heterocyclic group" in monomer B is preferably C1-C10 heterocyclic group, more preferably C2-C8 heterocyclic group, and even more preferably C2-C6 heterocyclic group, such as glycidyl, pyrrolidone, etc. The substituent "C1-C12 aromatic heterocyclic group" in monomer B is preferably C2-C10 aromatic heterocyclic group, more preferably C3-C8 aromatic heterocyclic group, and even more preferably C3-C6 aromatic heterocyclic group, such as imidazolyl.

[0013] In this invention, examples of monomer B include, but are not limited to, one or more combinations of the following monomers: maleic anhydride, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid and its alkali metal salts or ammonium salts, 3-methylpropane sulfonate, 3-propane sulfonate and its alkali metal salts or ammonium salts, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, ethyl 2-(dimethylamino)methacrylate, ethyl 2-(dimethylamino)acrylate, ethyl 2-(diethylamino)methacrylate, ethyl 2-(diethylamino)acrylate, propyl 3-(dimethylamino)acrylate. 3-(diethylamino)propyl acrylate, 3-(dimethylamino)propyl methacrylate, 3-(diethylamino)propyl methacrylate, vinyl acetate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, glycidyl methacrylate, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride, dimethyl diallyl ammonium chloride, diethyl diallyl ammonium chloride, allyl trimethylammonium chloride, allyl glycidyl ether, N-vinylpyrrolidone, vinylimidazole, 1-allyl-3-methylimidazolium chloride (or bromide), 2-hydroxyethyl methacrylate phosphate, vinylphosphonic acid, etc.

[0014] According to some embodiments of the present invention, monomer B comprises one or more of the following: C3-C10 unsaturated cyclic anhydrides, C3-C10 acrylamide monomers containing sulfonic acid functional groups, C3-C10 acrylamide monomers, phenyl-substituted C3-C10 unsaturated sulfonic acids or their salts, C2-C10 unsaturated phosphonic acids, and C3-C10 acrylamide monomers containing quaternary ammonium salt cations. In some embodiments, monomer B comprises one or more of the following: 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, sodium p-styrenesulfonate, maleic anhydride, vinylphosphonic acid, 3-methacrylamidopropyltrimethylammonium chloride, and 3-acrylamidopropyltrimethylammonium chloride.

[0015] According to some embodiments of the present invention, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is not less than 10%, preferably not less than 30%. In some embodiments, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is 30% to 99%, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, or any value between them.

[0016] According to some embodiments of the present invention, the weight-average molecular weight of the retarder is 500 to 500,000, preferably 1,000 to 300,000.

[0017] It should be noted that those skilled in the art can choose conventional polymerization methods to synthesize the retarder of the present invention. Exemplarily, as a specific embodiment, the preparation method of the retarder includes the following steps:

[0018] The monomer A and the monomer B are dissolved in water in a certain molar ratio to obtain a first solution;

[0019] The reducing agent and chain transfer agent 3-mercaptopropionic acid (5% of the total molar amount of monomers AA and AMPS) were dissolved in water to obtain a second solution;

[0020] The oxidant is mixed with the first solution and the second solution, and heated (e.g., 50-90°C) to react, thus obtaining the retarder.

[0021] The molar ratio of monomer A and monomer B can be (30-100):(0-70), for example (50-100):(0-50), or (50-99):(1-50).

[0022] Examples of reducing agents include, but are not limited to, ascorbic acid. Exemplarily, the amount of the reducing agent used is 0.1-2% of the total molar number of monomer A and monomer B, for example, 0.1%, 0.2%, 0.5%, 0.7%, 1.0%, 1.2%, 1.5%, 2%, or any value between them.

[0023] Examples of the chain transfer agents mentioned above include, but are not limited to, 3-mercaptopropionic acid. Exemplarily, the amount of the chain transfer agent used is 0.5-10% of the total molar number of monomer A and monomer B, for example, 0.5%, 1%, 2%, 3%, 5%, 8%, 10%, or any value between them.

[0024] Examples of the above-mentioned oxidants include, but are not limited to, hydrogen peroxide. Exemplarily, the amount of the oxidant used is 1-5% of the total molar number of monomer A and monomer B, for example, 1%, 2%, 3%, 5%, 8%, 10%, or any value between them.

[0025] According to some embodiments of the present invention, the retarder comprises any one or a combination of two or more of the following: polyacrylic acid, a copolymer of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid, a copolymer of acrylic acid and acrylamide, a copolymer of acrylic acid and N,N-dimethylacrylamide, a copolymer of acrylic acid and N-methylacrylamide, a copolymer of acrylic acid and N,N-diethylacrylamide, a copolymer of acrylic acid and methacrylamide, a copolymer of acrylic acid and isopropylacrylamide, a copolymer of acrylic acid and N-hydroxymethylacrylamide, a copolymer of acrylic acid and N-hydroxyethylacrylamide, a copolymer of acrylic acid and sodium p-styrenesulfonate, a copolymer of acrylic acid and maleic anhydride, a copolymer of acrylic acid and vinylphosphonic acid, a copolymer of acrylic acid and 3-methacrylamidopropyltrimethylammonium chloride, and a copolymer of acrylic acid and 3-acrylamidopropyltrimethylammonium chloride.

[0026] According to some embodiments of the present invention, the retarder accounts for 0.5%-5% of the weight of the cementitious material, for example, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5% or any value between them, preferably 2%-5%.

[0027] In this invention, the cementing material includes, but is not limited to, one or a mixture of two or more powders rich in silica-alumina mineral phases, such as metallurgical slag, fly ash, volcanic ash, metakaolin, and cement.

[0028] According to some embodiments of the present invention, the cementing material includes one or more of blast furnace slag, steel slag, fly ash, volcanic ash, metakaolin, and silicate cement. In some embodiments, the cementing material is blast furnace slag, a mixture of blast furnace slag and metakaolin, or a mixture of blast furnace slag and fly ash.

[0029] In some embodiments, the cementing material is blast furnace slag. In some embodiments, the cementing material is a mixture of blast furnace slag and metakaolin, wherein the mass ratio of blast furnace slag to metakaolin is preferably 1:(0.5-2). In some embodiments, the cementing material is a mixture of blast furnace slag and fly ash, wherein the mass ratio of blast furnace slag to fly ash is preferably 1:(0.5-2). In some embodiments, when the cementing material is of multiple types, the mass percentage of the high-calcium component is ≥20%, wherein the high-calcium component refers to a component with a calcium oxide content ≥25% (mass percentage).

[0030] The alkali activator of this invention comprises one or more of oxides, hydroxides, and salts (including inorganic and organic salts) of alkali metals or alkaline earth metals, including but not limited to: one or more of carbonates, sulfates, silicates, aluminates, formates, acetates, and hydroxides of alkali metals or alkaline earth metals. In some embodiments, the alkali activator comprises one or more of sodium hydroxide, sodium silicate, sodium carbonate, sodium sulfate, and calcium hydroxide. In some embodiments, the alkali activator comprises sodium hydroxide. In some embodiments, the alkali activator comprises sodium silicate. In some embodiments, the alkali activator comprises sodium hydroxide and sodium sulfate. When sodium hydroxide and sodium sulfate are used as alkali activators, the mass ratio of sodium hydroxide to sodium sulfate can be 1:(1.5-5), preferably 1:(1.5-3).

[0031] According to some embodiments of the present invention, the alkali activator accounts for 3%-80% of the weight of the cementitious material, for example, 3%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or any value between therewith, preferably 6%-20%.

[0032] On the other hand, the present invention provides an alkali-activated gelling material, wherein the raw materials for preparing the alkali-activated gelling material include the gelling composition described above in the present invention, or the alkali-activated gelling material is prepared from raw materials including the gelling composition described above in the present invention.

[0033] In some embodiments, the alkali-activated gelling material is used at a temperature of 5-250°C. In some embodiments, the alkali-activated gelling material is used at a temperature of 25-130°C.

[0034] In some embodiments, the preparation method of the alkali-activated gelling material includes the following steps:

[0035] The gelling composition is mixed with water and then cured and maintained.

[0036] In the above preparation method, there is no special limitation on the way each raw material is added. For example, the alkali activator in the gelling composition can be mixed with water first, and then mixed with the gelling material in the gelling composition; or the alkali activator in the gelling composition can be mixed with the gelling material in the gelling composition and then mixed with water.

[0037] In some embodiments, the mass ratio of water to the cementitious material in the cementitious composition (water-to-solid ratio) is 0.5 to 0.6.

[0038] In another aspect, the present invention provides the application of the above-mentioned cementitious composition in the preparation of building materials.

[0039] The alkali-activated cementitious material prepared using the cementing composition of the present invention can be used in environments such as low temperature (e.g., 5-20°C), normal temperature (e.g., 20-40°C), and high temperature (e.g., 40-250°C), and can be used as cementing cement for oil and gas wells.

[0040] In another aspect, the present invention also provides the application of polycarboxylic acid polymers in oil and gas well cementing, wherein the polycarboxylic acid polymers serve as retarders for the oil and gas well cementing, and the polycarboxylic acid polymers include any one or more combinations of homopolymers of monomer A, copolymers of monomer A and monomer B; monomer A includes unsaturated carboxylic acid monomers; the unsaturated carboxylic acid monomers may contain one selected from ester groups (-COO-), amide groups (-CO-NH-), and hydroxyl groups (-OH). The monomer B may contain one or more functional groups; or it may not contain these functional groups. The monomer B includes a polymerizable monomer containing a carbon-carbon double bond. The monomer B may contain one or more functional groups selected from quaternary ammonium salt cations, sulfonate anions, acid anhydrides, sulfonic acid groups, ester groups, -C(=O)-OC(=O)-, amide groups, hydroxyl groups, amino groups, amine groups, ether bonds, phosphonic acid groups, and phosphonate ester groups, or it may not contain these functional groups. In addition, the monomer B may not contain substituents, or it may contain one or more substituents selected from heterocyclic groups, aryl groups, and heteroaryl groups.

[0041] According to some embodiments of the present invention, monomer A comprises one or more of C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids. In some embodiments, the C3-C10 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C10 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C10 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0042] According to some embodiments of the present invention, monomer A comprises one or more of C3-C8 monounsaturated carboxylic acids, C4-C8 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids. In some embodiments, the C3-C8 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C8 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C8 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0043] According to some embodiments of the present invention, monomer A comprises one or more of C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids. In some embodiments, the C3-C6 monounsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C4-C6 diunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups. In some embodiments, the C5-C8 triunsaturated carboxylic acid contains one or more functional groups selected from ester, amide, and hydroxyl groups.

[0044] In this invention, examples of monomer A include, but are not limited to, one or more combinations of the following monomers: acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, medaconic acid, crotonic acid, citraconic acid, acryloyloxypropionic acid, methacryloyloxypropionic acid, vinylacetic acid, monomethyl itaconic acid, monomethyl fumarate, monobutyl fumarate, acrylamide glycolic acid, methacrylamide glycolic acid, etc.

[0045] According to some embodiments of the present invention, monomer A comprises a C3-C6 monounsaturated carboxylic acid. According to some embodiments of the present invention, monomer A comprises a C3-C4 monounsaturated carboxylic acid. In some embodiments, monomer A comprises one or more of acrylic acid and methacrylic acid. In some embodiments, monomer A comprises acrylic acid.

[0046] According to some embodiments of the present invention, the monomer B comprises C3-C10 unsaturated chain anhydrides, C3-C10 unsaturated cyclic anhydrides, C2-C10 unsaturated sulfonic acids, C3-C10 unsaturated fatty amides containing sulfonic acid functional groups, C3-C10 unsaturated sulfonic acids substituted with C6-C15 aryl groups (e.g., phenyl) or their salts, C3-C10 unsaturated fatty acid esters containing sulfonic acid functional groups or their salts, C3-C10 chain or cyclic unsaturated fatty amides, hydroxyl-containing C3-C10 unsaturated fatty amides, C3-C10 unsaturated fatty acid esters containing amino functional groups (e.g., dimethylamino, diethylamino, etc.), C3-C10 unsaturated fatty acid esters, and hydroxyl-containing C3-C10 unsaturated fatty acids. Ester, C3-C10 unsaturated fatty acid esters substituted with C1-C12 heterocyclic groups, C3-C10 unsaturated fatty acid esters containing ether bonds, C3-C10 unsaturated fatty acid esters containing quaternary ammonium salt cations, C3-C10 unsaturated fatty amides containing quaternary ammonium salt cations, C2-C10 olefin monomers containing quaternary ammonium salt cations, C3-C10 unsaturated ether monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 aromatic heterocyclic groups, C2-C10 olefin monomers containing imidazole cations, C2-C10 unsaturated phosphonic acids, and C3-C10 unsaturated phosphonate esters, or one or more of these.

[0047] In this invention, examples of monomer B include, but are not limited to, one or more combinations of the following monomers: maleic anhydride, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid and its alkali metal salts or ammonium salts, 3-methylpropane sulfonate, 3-propane sulfonate and its alkali metal salts or ammonium salts, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, ethyl 2-(dimethylamino)methacrylate, ethyl 2-(dimethylamino)acrylate, ethyl 2-(diethylamino)methacrylate, ethyl 2-(diethylamino)acrylate, propyl 3-(dimethylamino)acrylate. 3-(diethylamino)propyl acrylate, 3-(dimethylamino)propyl methacrylate, 3-(diethylamino)propyl methacrylate, vinyl acetate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, glycidyl methacrylate, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride, dimethyl diallyl ammonium chloride, diethyl diallyl ammonium chloride, allyl trimethylammonium chloride, allyl glycidyl ether, N-vinylpyrrolidone, vinylimidazole, 1-allyl-3-methylimidazolium chloride (or bromide), 2-hydroxyethyl methacrylate phosphate, vinylphosphonic acid, etc.

[0048] According to some embodiments of the present invention, monomer B comprises one or more of the following: C3-C8 unsaturated cyclic anhydrides, C3-C10 acrylamide monomers containing sulfonic acid functional groups, C3-C10 acrylamide monomers, phenyl-substituted C3-C10 unsaturated sulfonic acids or their salts, C2-C10 unsaturated phosphonic acids, and C3-C10 acrylamide monomers containing quaternary ammonium salt cations. In some embodiments, monomer B comprises one or more of the following: 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, sodium p-styrenesulfonate, maleic anhydride, vinylphosphonic acid, 3-methacrylamidopropyltrimethylammonium chloride, and 3-acrylamidopropyltrimethylammonium chloride.

[0049] According to some embodiments of the present invention, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is not less than 10%, preferably not less than 30%. In some embodiments, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is 30% to 99%. In some embodiments, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is 50% to 99%.

[0050] According to some embodiments of the present invention, the weight-average molecular weight of the polycarboxylic acid polymer is 500 to 500,000, preferably 1,000 to 300,000.

[0051] According to some embodiments of the present invention, the polycarboxylic acid polymer includes any one or a combination of two or more of the following: polyacrylic acid, a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid, a copolymer of acrylic acid and acrylamide, a copolymer of acrylic acid and N,N-dimethylacrylamide, a copolymer of acrylic acid and N-methylacrylamide, a copolymer of acrylic acid and N,N-diethylacrylamide, a copolymer of acrylic acid and methacrylamide, a copolymer of acrylic acid and isopropylacrylamide, a copolymer of acrylic acid and N-hydroxymethylacrylamide, a copolymer of acrylic acid and N-hydroxyethylacrylamide, a copolymer of acrylic acid and sodium p-styrenesulfonate, a copolymer of acrylic acid and maleic anhydride, a copolymer of acrylic acid and vinylphosphonic acid, a copolymer of acrylic acid and 3-methacrylamidopropyltrimethylammonium chloride, and a copolymer of acrylic acid and 3-acrylamidopropyltrimethylammonium chloride.

[0052] According to some embodiments of the present invention, the raw materials for preparing the cement for oil and gas wells include cementitious materials, alkali activators, and retarders, wherein the retarders include the aforementioned polycarboxylic acid polymers.

[0053] In some embodiments, the retarder accounts for 0.5%-5% of the weight of the cementitious material, for example, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5% or any value between them, preferably 2%-5%.

[0054] In this invention, the cementing material includes, but is not limited to, one or a mixture of two or more of the following powders rich in silica-alumina mineral phases: metallurgical slag, fly ash, volcanic ash, metakaolin, cement, etc.

[0055] In some embodiments, the cementing material includes one or more of blast furnace slag, steel slag, fly ash, volcanic ash, metakaolin, and silicate cement. In some embodiments, the cementing material is blast furnace slag, a mixture of blast furnace slag and metakaolin, or a mixture of blast furnace slag and fly ash. In some embodiments, the cementing material is blast furnace slag. In some embodiments, the cementing material is a mixture of blast furnace slag and metakaolin, wherein the mass ratio of blast furnace slag to metakaolin is preferably 1:(0.5-2). In some embodiments, the cementing material is a mixture of blast furnace slag and fly ash, wherein the mass ratio of blast furnace slag to fly ash is preferably 1:(0.5-2). In some embodiments, when the cementing material is multiple, the mass percentage of the high-calcium component is ≥20%, wherein the high-calcium component refers to a component with a calcium oxide content ≥25% (mass percentage).

[0056] The alkali activator of this invention comprises one or more of oxides, hydroxides, and salts (including inorganic and organic salts) of alkali metals or alkaline earth metals, including but not limited to: one or more of carbonates, sulfates, silicates, aluminates, formates, acetates, and hydroxides of alkali metals or alkaline earth metals. In some embodiments, the alkali activator comprises one or more of sodium hydroxide, sodium silicate, sodium carbonate, sodium sulfate, and calcium hydroxide. In some embodiments, the alkali activator comprises sodium hydroxide. In some embodiments, the alkali activator comprises sodium silicate. In some embodiments, the alkali activator comprises sodium hydroxide and sodium sulfate. When sodium hydroxide and sodium sulfate are used as alkali activators, the mass ratio of sodium hydroxide to sodium sulfate can be 1:(1.5-5), preferably 1:(1.5-3). In some embodiments, the alkali activator accounts for 3%-80% of the weight of the cementitious material, for example, 3%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or any value between therewith, preferably 6%-20%.

[0057] In some embodiments, the operating temperature of the oil and gas well cement is 5-250°C. In some embodiments, the operating temperature of the oil and gas well cement is 25-130°C.

[0058] In some embodiments, the method for preparing the cement for oil and gas wells includes the following steps:

[0059] The gelling composition is mixed with water and then cured and maintained.

[0060] In the above preparation method, there is no special limitation on the way each raw material is added. For example, the alkali activator in the gelling composition can be mixed with water first, and then mixed with the gelling material in the gelling composition; or the alkali activator in the gelling composition can be mixed with the gelling material in the gelling composition and then mixed with water.

[0061] In some embodiments, the mass ratio of water to the cementitious material in the cementitious composition (water-to-solid ratio) is 0.5 to 0.6.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] (1) The gelling composition of the present invention contains a polycarboxylic acid polymer as a retarder. The polycarboxylic acid polymer is a homopolymer of unsaturated carboxylic acid monomers or a copolymer of unsaturated carboxylic acid and unsaturated small molecule monomers. It can effectively delay the setting time of alkali-activated gelling materials, so that alkali-activated gelling materials can be used in different temperature ranges and maintain high mechanical strength.

[0064] (2) This invention provides new uses for polycarboxylic acid polymers, offering more options for alkali-activated gelling retarder and broadening the application prospects of alkali-activated gelling materials. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0066] Unless otherwise specified, all reagents used in the following experiments of this invention are commercially available products or reagents prepared according to conventional methods. Unless otherwise specified, all methods used in the experiments are conventional experimental methods. Unless otherwise specified, all instruments used in the experiments are commercially available.

[0067] Table 1 below lists the number, name, monomer type, and molecular weight of the retarders used in the following embodiments of the present invention.

[0068] Table 1

[0069]

[0070]

[0071] The synthesis method of retarder P1 is as follows:

[0072] 1) Dissolve monomers AA and AMPS in water at a molar ratio of 95.24%:4.76% to obtain a solution S1 with a solid content of 60%;

[0073] 2) The reducing agent ascorbic acid (0.7% of the total moles of monomers AA and AMPS) and the chain transfer agent 3-mercaptopropionic acid (2% of the total moles of monomers AA and AMPS) were dissolved in water to obtain a solution S2 with a solid content of 5%.

[0074] 3) Take 1 / 10 of the mass of the solution S1 prepared in step 1) and add it to a three-necked flask, and heat it to a constant temperature of 65 degrees Celsius;

[0075] 4) Add the oxidizing agent hydrogen peroxide (2% of the total molar amount of monomers AA and AMPS) to the three-necked flask all at once, and then add the remaining 9 / 10 of the mass of solution S1 and all of solution S2 dropwise to the three-necked flask in steps, with solution S1 being added dropwise over 3 hours and solution S2 over 3.5 hours.

[0076] 5) After the addition is complete, keep the temperature at 65 degrees Celsius for 1 hour, and then cool it down to room temperature to obtain polymer AA-AMPS-20.

[0077] The synthesis methods of other polymer retarders in Table 1 are the same as those for polymer retarder P1. In the synthesis of retarder P8, the molar amounts of oxidant, reducing agent, and chain transfer agent are 2%, 0.7%, and 1% of the total molar amounts of the monomers, respectively.

[0078] The above-described polymer synthesis method is only used to illustrate the preparation process of the polymer retarder in the examples, and does not limit the synthesis method of the polymer retarder in this application.

[0079] Example

[0080] Preparation of alkali-activated cementitious materials:

[0081] Weigh the samples according to the composition (precursor, activator, retarder) of each embodiment in Table 2. Mix the activator and water to obtain the activator solution. Directly mix the precursor, activator solution and retarder and stir thoroughly to obtain the sample to be tested.

[0082] The preparation of the alkali-activated gelling materials in each comparative example was carried out in accordance with the method described in the above examples.

[0083] The results of the setting time tests for the samples prepared in each embodiment and control example are shown in Table 2. The method for testing the setting time is as follows:

[0084] The test was conducted according to GB / T 1346-2011 Standard Test Methods for Water Requirement, Setting Time and Soundness of Cement.

[0085] In Comparative Examples 5 and 7, the ratio of water to precursor was 0.6:1, while in other comparative examples and examples, the ratio of water to precursor was 0.5:1.

[0086] Table 2

[0087]

[0088]

[0089] Note: The dosage of retarder in Table 2 refers to the dosage in the precursor.

[0090] A comparison of Example 1 and Examples 1-3 shows that the polymer retarder of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated gelling materials, and the initial setting time and final setting time will be relatively longer when the retarder dosage is higher.

[0091] A comparison with Examples 1-2 and Examples 2 and 4 shows that the polymer retarder of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated gelling materials under different sodium hydroxide dosages. Furthermore, when the sodium hydroxide dosage is higher, the initial setting time and final setting time of alkali-activated gelling materials are slightly shortened.

[0092] A comparison of Examples 1-4 and Examples 2 and 5-6 shows that the polymer retarder of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated cementitious materials when using different types of activators. Compared with sodium hydroxide, the initial setting time and final setting time of alkali-activated cementitious materials are relatively longer when water glass is used as an alkali activator or when sodium hydroxide-sodium sulfate composite alkali activator is used.

[0093] A comparison with Examples 1, 5-6 and Examples 2, 7-8 shows that the polymer retarder of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated cementitious materials in different precursor systems. Moreover, compared with the slag-high tertiary system, the initial setting time and final setting time of alkali-activated cementitious materials are relatively longer in the pure slag system or the slag-fly ash system.

[0094] A comparison with Examples 1, 7-8 and Examples 2, 9-10 shows that the polymer retarder of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated gelling materials at different temperatures, and the initial setting time and final setting time at 25°C and 60°C are relatively longer than those at 95°C.

[0095] A comparison with Example 1 and Examples 2 and 11-17 shows that different types of polymer retarders of the present invention can significantly prolong the initial setting time and final setting time of alkali-activated gelling materials.

[0096] A comparison with Examples 1 and 9 and Example 1 shows that the polymer retarder of the present invention has a better retarding effect on alkali-activated gelling materials compared with the existing borax retarder.

[0097] A comparison of Example 1 and Examples 1 and 17 shows that retarders with larger molecular weights have a better retarding effect than retarders with smaller molecular weights.

[0098] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A gelling composition comprising a gelling material, an alkali activator, and a retarder; wherein, The retarder includes any one or a combination of two or more of the following: homopolymer of monomer A, copolymer of monomer A and monomer B. The monomer A includes an unsaturated carboxylic acid monomer; optionally, the unsaturated carboxylic acid monomer contains one or more functional groups selected from ester, amide, and hydroxyl groups. The monomer B comprises a polymerizable monomer containing a carbon-carbon double bond; optionally, the monomer B contains one or more functional groups selected from quaternary ammonium cations, sulfonate anions, acid anhydrides, sulfonic acid groups, ester groups, -C(=O)-OC(=O)-, amide groups, hydroxyl groups, amino groups, amine groups, ether bonds, phosphonic acid groups, and phosphonate ester groups; and / or, the monomer B contains one or more substituents selected from heterocyclic groups, aryl groups, and heteroaryl groups.

2. The gelling composition according to claim 1, characterized in that, The monomer A comprises one or more of the following: C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids; optionally, each of the C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids independently contains one or more functional groups selected from ester groups, amide groups, and hydroxyl groups; Preferably, monomer A comprises one or more of C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids; optionally, each of the C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids independently contains 1 to 2 functional groups selected from ester groups, amide groups, and hydroxyl groups; Preferably, monomer A comprises one or more of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, medaconic acid, crotonic acid, citraconic acid, acryloyloxypropionic acid, methacryloyloxypropionic acid, vinylacetic acid, monomethyl itaconic acid, monomethyl fumarate, monobutyl fumarate, acrylamide glycolic acid, and methacrylamide glycolic acid. Preferably, monomer A comprises a C3-C6 monounsaturated carboxylic acid; more preferably, monomer A comprises acrylic acid and / or methacrylic acid.

3. The gelling composition according to claim 1, characterized in that, The monomer B comprises C3-C10 unsaturated chain anhydrides, C3-C10 unsaturated cyclic anhydrides, C2-C10 unsaturated sulfonic acids, C3-C10 unsaturated fatty amides containing sulfonic acid functional groups, C3-C10 unsaturated sulfonic acids or their salts substituted with C6-C15 aryl groups, C3-C10 unsaturated fatty acid esters or their salts containing sulfonic acid functional groups, C3-C10 chain or cyclic unsaturated fatty amides, hydroxyl-containing C3-C10 unsaturated fatty amides, C3-C10 unsaturated fatty acid esters containing amino functional groups, C3-C10 unsaturated fatty acid esters, hydroxyl-containing C3-C10 unsaturated fatty acid esters, and C3-C10 unsaturated fatty acid esters substituted with C1-C12 heterocyclic groups. The following are some of the following: -C10 unsaturated fatty acid esters, C3-C10 unsaturated fatty acid esters containing ether bonds, C3-C10 unsaturated fatty acid esters containing quaternary ammonium salt cations, C3-C10 unsaturated fatty amides containing quaternary ammonium salt cations, C2-C10 olefin monomers containing quaternary ammonium salt cations, C3-C10 unsaturated ether monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 aromatic heterocyclic groups, C2-C10 olefin monomers containing imidazole cations, C2-C10 unsaturated phosphonic acids, and C3-C10 unsaturated phosphonate esters; Preferably, monomer B comprises maleic anhydride, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid and its alkali metal salt or ammonium salt, 3-methylpropane sulfonate, 3-acrylate sulfonate and its alkali metal salt or ammonium salt, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, 2-(dimethylamino)methacrylate, 2-(dimethylamino)acrylate, 2-(diethylamino)methacrylate, 2-(diethylamino)acrylate, 3-(dimethylamino)acrylate, 3-(diethylamino)acrylate, 3-(dimethylamino)acrylate, 3-(dimethylamino)acrylate, 3-(dimethylamino)meth ... The following are one or more of the following: (amino)propyl methacrylate, 3-(diethylamino)propyl methacrylate, vinyl acetate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, glycidyl methacrylate, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride, dimethyldiallyl ammonium chloride, diethyldiallyl ammonium chloride, allyltrimethylammonium chloride, allyl glycidyl ether, N-vinylpyrrolidone, vinylimidazole, 1-allyl-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium bromide, 2-hydroxyethyl methacrylate phosphate, and vinylphosphonic acid; Preferably, the monomer B comprises one or more of the following: C3-C8 unsaturated cyclic anhydrides, C3-C10 acrylamide monomers containing sulfonic acid functional groups, C3-C10 acrylamide monomers, C3-C10 unsaturated sulfonic acids or their salts substituted with phenyl groups, C2-C10 unsaturated phosphonic acids, and C3-C10 acrylamide monomers containing quaternary ammonium salt cations; Preferably, monomer B comprises one or more of 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, sodium p-styrenesulfonate, maleic anhydride, vinylphosphonic acid, 3-methacrylamidopropyltrimethylammonium chloride, and 3-acrylamidopropyltrimethylammonium chloride.

4. The gelling composition according to claim 1, characterized in that, In the copolymer of monomer A and monomer B, the molar percentage of monomer A is not less than 10%, preferably not less than 30%, and more preferably 50% to 99%; and / or, The retarder has a weight-average molecular weight of 500–500,000, preferably 1,000–300,000; and / or, The retarder comprises any one or a combination of two or more of the following: polyacrylic acid, a copolymer of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid, a copolymer of acrylic acid and acrylamide, a copolymer of acrylic acid and N,N-dimethylacrylamide, a copolymer of acrylic acid and N-methylacrylamide, a copolymer of acrylic acid and N,N-diethylacrylamide, a copolymer of acrylic acid and methacrylamide, a copolymer of acrylic acid and isopropylacrylamide, a copolymer of acrylic acid and N-hydroxymethylacrylamide, a copolymer of acrylic acid and N-hydroxyethylacrylamide, a copolymer of acrylic acid and sodium p-styrenesulfonate, a copolymer of acrylic acid and maleic anhydride, a copolymer of acrylic acid and vinylphosphonic acid, a copolymer of acrylic acid and 3-methacrylamidopropyltrimethylammonium chloride, and a copolymer of acrylic acid and 3-acrylamidopropyltrimethylammonium chloride.

5. The gelling composition according to claim 1, characterized in that, The cementing material includes one or more of blast furnace slag, steel slag, fly ash, volcanic ash, metakaolin, and silicate cement, preferably blast furnace slag, a mixture of blast furnace slag and metakaolin, or a mixture of blast furnace slag and fly ash; and / or, The alkaline activator comprises one or more of oxides, hydroxides, and salts of alkali metals or alkaline earth metals, preferably one or more of carbonates, sulfates, silicates, aluminates, formates, acetates, and hydroxides of alkali metals or alkaline earth metals, more preferably one or more of sodium hydroxide, sodium silicate, sodium carbonate, sodium sulfate, and calcium hydroxide; and / or, The retarder accounts for 0.5%-5% of the weight of the cementitious material, preferably 2%-5%; and / or, The alkali activator accounts for 3%-80% of the weight of the cementitious material, preferably 6%-20%.

6. An alkali-activated gelling material, wherein the raw materials for its preparation include the gelling composition according to any one of claims 1-5, or it is prepared from raw materials including the gelling composition according to any one of claims 1-5; Preferably, the alkali-activated gelling material is used at a temperature of 5-250°C, more preferably 25-180°C; Preferably, the preparation method of the alkali-activated gelling material includes the following steps: The gelling composition is mixed with water and then cured and maintained. Preferably, the mass ratio of water to the cementitious material in the cementitious composition is 0.5 to 0.

6.

7. The use of the cementitious composition according to any one of claims 1-5 in the preparation of building materials, preferably in the cementing of oil and gas wells.

8. Application of polycarboxylate polymers in oil and gas well cementing, among which, The polycarboxylic acid polymer compound is used as a retarder for the cementing of the oil and gas wells; The polycarboxylic acid polymers include any one or more combinations of homopolymers of monomer A and copolymers of monomer A and monomer B. The monomer A includes an unsaturated carboxylic acid monomer; optionally, the unsaturated carboxylic acid monomer contains one or more functional groups selected from ester, amide, and hydroxyl groups. The monomer B comprises a polymerizable monomer containing a carbon-carbon double bond; optionally, the monomer B contains one or more functional groups selected from quaternary ammonium cations, sulfonate anions, acid anhydrides, sulfonic acid groups, ester groups, -C(=O)-OC(=O)-, amide groups, hydroxyl groups, amino groups, amine groups, ether bonds, phosphonic acid groups, and phosphonate ester groups; and / or, the monomer B contains one or more substituents selected from heterocyclic groups, aryl groups, and heteroaryl groups.

9. The application according to claim 8, characterized in that, The monomer A comprises one or more of C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids; optionally, each of the C3-C10 monounsaturated carboxylic acids, C4-C10 diunsaturated carboxylic acids, and C5-C10 triunsaturated carboxylic acids independently contains one or more functional groups selected from ester groups, amide groups, and hydroxyl groups; the monomer B comprises C3-C10 unsaturated chain anhydrides, C3-C10 unsaturated cyclic anhydrides, C2-C10 unsaturated sulfonic acids, C3-C10 unsaturated fatty amides containing sulfonic acid functional groups, C3-C10 unsaturated sulfonic acids substituted with C6-C15 aryl groups or their salts, C3-C10 unsaturated fatty acid esters containing sulfonic acid functional groups or their salts, C3-C10 chain or cyclic unsaturated fatty amides, C3-C10 unsaturated fatty amides containing hydroxyl groups, and so on. The following are included in the following categories: C3-C10 unsaturated fatty acid esters with amino functional groups, C3-C10 unsaturated fatty acid esters, C3-C10 unsaturated fatty acid esters containing hydroxyl groups, C3-C10 unsaturated fatty acid esters substituted with C1-C12 heterocyclic groups, C3-C10 unsaturated fatty acid esters containing ether bonds, C3-C10 unsaturated fatty acid esters containing quaternary ammonium salt cations, C3-C10 unsaturated fatty amides containing quaternary ammonium salt cations, C2-C10 olefin monomers containing quaternary ammonium salt cations, C3-C10 unsaturated ether monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 heterocyclic groups, C2-C10 olefin monomers substituted with C1-C12 aromatic heterocyclic groups, C2-C10 olefin monomers containing imidazole cations, C2-C10 unsaturated phosphonic acids, and C3-C10 unsaturated phosphonate esters. Preferably, monomer A comprises one or more of C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids; optionally, each of the C3-C6 monounsaturated carboxylic acids, C4-C6 diunsaturated carboxylic acids, and C5-C8 triunsaturated carboxylic acids independently contains 1 to 2 functional groups selected from ester groups, amide groups, and hydroxyl groups; monomer B comprises one or more of C3-C8 unsaturated cyclic anhydrides, C3-C10 acrylamide monomers containing sulfonic acid functional groups, C3-C10 acrylamide monomers, C3-C10 unsaturated sulfonic acids or their salts substituted with phenyl groups, C2-C10 unsaturated phosphonic acids, and C3-C10 acrylamide monomers containing quaternary ammonium salt cations; Preferably, monomer A comprises one or more of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, medaconic acid, crotonic acid, citraconic acid, acryloyloxypropionic acid, methacryloyloxypropionic acid, vinylacetic acid, monomethyl itaconic acid, monomethyl fumarate, monobutyl fumarate, acrylamidohydroxyacetic acid, and methacrylamidohydroxyacetic acid; monomer B comprises maleic anhydride, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, and 2-acrylamido-2-methylpropionic acid. Sulfonic acid, styrene sulfonic acid and its alkali metal salts or ammonium salts, 3-methylpropionic acid sulfonyl ester, 3-acrylate sulfonyl ester and its alkali metal salts or ammonium salts, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, 2-(dimethylamino)methacrylate, 2-(dimethylamino)acrylate, 2-(dimethylamino)methacrylate Ethyl methacrylate (ethyl 2-(diethylamino)acrylate), ethyl 2-(diethylamino)acrylate, propyl 3-(dimethylamino)acrylate, propyl 3-(diethylamino)acrylate, propyl 3-(dimethylamino)methacrylate, propyl 3-(diethylamino)methacrylate, vinyl acetate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, glycidyl methacrylate, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride, 3-acrylamidopropyltrimethylammonium chloride, dimethyldiallyl ammonium chloride, diethyldiallyl ammonium chloride, allyltrimethylammonium chloride, allyl glycidyl ether, N-vinylpyrrolidone, vinylimidazole, 1-allyl-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium bromide, 2-hydroxyethyl methacrylate phosphate, vinylphosphonic acid; Preferably, monomer A comprises one or more of acrylic acid and methacrylic acid; monomer B comprises one or more of 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, N,N-dimethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, methacrylamide, isopropylacrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, sodium p-styrenesulfonate, maleic anhydride, vinylphosphonic acid, 3-methacrylamidopropyltrimethylammonium chloride, and 3-acrylamidopropyltrimethylammonium chloride. Preferably, in the copolymer of monomer A and monomer B, the molar percentage of monomer A is not less than 10%, more preferably not less than 30%, and more preferably 50% to 99%. Preferably, the polycarboxylic acid polymer has a weight-average molecular weight of 500 to 500,000, more preferably 1,000 to 300,000; Preferably, the polycarboxylic acid polymer includes any one or a combination of two or more of the following: polyacrylic acid, a copolymer of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid, a copolymer of acrylic acid and acrylamide, a copolymer of acrylic acid and N,N-dimethylacrylamide, a copolymer of acrylic acid and N-methylacrylamide, a copolymer of acrylic acid and N,N-diethylacrylamide, a copolymer of acrylic acid and methacrylamide, a copolymer of acrylic acid and isopropylacrylamide, a copolymer of acrylic acid and N-hydroxymethylacrylamide, a copolymer of acrylic acid and N-hydroxyethylacrylamide, a copolymer of acrylic acid and sodium p-styrenesulfonate, a copolymer of acrylic acid and maleic anhydride, a copolymer of acrylic acid and vinylphosphonic acid, a copolymer of acrylic acid and 3-methacrylamidopropyltrimethylammonium chloride, and a copolymer of acrylic acid and 3-acrylamidopropyltrimethylammonium chloride.

10. The application according to claim 8 or 9, characterized in that, The raw materials for preparing the cement for oil and gas wells include cementitious materials, alkali activators, and retarders. The retarders include polycarboxylic acid polymers. The cementitious materials include one or more of blast furnace slag, steel slag, fly ash, volcanic ash, metakaolin, and silicate cement, preferably blast furnace slag, a mixture of blast furnace slag and metakaolin, or a mixture of blast furnace slag and fly ash. The alkaline activator includes one or more of oxides, hydroxides and salts of alkali metals or alkaline earth metals, preferably one or more of carbonates, sulfates, silicates, aluminates, formates, acetates and hydroxides of alkali metals or alkaline earth metals, and more preferably one or more of sodium hydroxide, sodium silicate, sodium carbonate, sodium sulfate and calcium hydroxide. Preferably, the retarder accounts for 0.5%-5% of the weight of the cementitious material, more preferably 2%-5%; Preferably, the alkali activator accounts for 3%-80% of the weight of the cementitious material, more preferably 6%-20%; Preferably, the application temperature of the cement for oil and gas wells is 5-250℃, more preferably 25-180℃.

Images