Abnormal cementing material of cement slurry and preparation method and application thereof

Abstract

The application discloses a cementing slurry abnormal gelation prevention material and a preparation method and application thereof, and relates to the technical field of cementing materials for oil and gas well engineering. The cementing slurry abnormal gelation prevention material comprises, in terms of weight parts, 40-60 parts of ulexite, 20-40 parts of priceite, 10-20 parts of searlesite and 5-15 parts of chalcanthite. The cementing slurry abnormal gelation prevention material can be used in a ten-thousand-meter ultra-deep well, is an inorganic material, can ensure stable performance and no failure in an ultra-high temperature environment, and has good adaptability to a cement base material, a high-temperature external admixture and an external additive, and has a wide application range.

Description

Technical Field

[0001] The present invention relates to the technical field of cementing materials for oil and gas well engineering, and more particularly to a cementing slurry anti-abnormal gelling material and a preparation method and application thereof. Background Art

[0002] 39% of my country's remaining onshore oil and 57% of its remaining natural gas are located in deep reservoirs. Ultra-deep oil and gas resources at depths exceeding 10,000 meters have become a key area for increasing reserves and production in my country's oil and gas reservoirs. During oil and gas well development, cementing is a key engineering technology for ensuring safe production throughout the wellbore's lifecycle and achieving profitable development. Due to the high-temperature working environment downhole, especially when temperatures exceed 180°C, the hydration and hardening process of oil well cement, the composition of hydration products, and the performance of retarders all undergo significant changes, which can significantly affect the stability of cement slurry thickening properties. This is primarily manifested in abnormal gelation during slurry heating and difficulty in linearly adjusting the thickening time. Abnormal cement slurry gelation can significantly impact cementing safety, making it an urgent technical challenge to address during the exploration and development of 10,000-meter deep wells.

[0003] Existing technical approaches primarily focus on optimizing the composition of fluid loss additives and retarders. For example, the invention patent application, entitled "A fluid loss additive for inhibiting premature abnormal gelation of cement slurry and its preparation method," published on July 29, 2022, with application publication number CN114805706A, specifically discloses that the fluid loss additive is a tetrapolymer comprising 55-70 parts of component A, 10-15 parts of component B, 10-15 parts of component C, and 10-15 parts of component D. Component A is AMPS or an AMPS salt, component B is an acrylamide, component C is tannin, and component D is a nitrogen-substituted acrylamide. The resulting product exhibits excellent performance in inhibiting premature abnormal gelation of cement slurry, while also possessing the essential properties required of a fluid loss additive, such as reducing fluid loss and adjusting cement slurry rheology.

[0004] For example, the invention patent application, entitled "A Multi-stage Adsorption Polymer Fluid Loss Additive and Its Preparation Method," published on April 18, 2022, with application publication number CN114292634A, specifically discloses that the multi-stage adsorption polymer fluid loss additive is composed of 35% to 60% binary copolymer, 20% to 40% ternary copolymer, and 10% to 30% tetrapolymer. The resulting product can be used for ultra-high-temperature deep well cementing, with an applicable temperature range of 30°C to 210°C. It can effectively prevent deterioration of cement slurry stability caused by excessive dispersion at high temperatures and improve abnormal gelation of cement slurry due to excessive strong adsorption groups.

[0005] For example, the invention patent application publication date is September 15, 2020, the application publication number is CN111662409A, and the name is “A high-temperature oil well cement retarder capable of inhibiting abnormal gelation and its preparation method”. It specifically discloses that its preparation method includes (1) dissolving 2-acrylamido-2-methylpropanesulfonic acid and unsaturated carboxylic acid monomers in deionized water, stirring evenly, and adjusting the pH to 5-6; (2) adding steric hindrance functional monomers and cationic functional monomers to the solution obtained in step (1), stirring evenly, and heating to 55-65°C; (3) dissolving the initiator in deionized water to form a solution, adding it to the solution obtained in step (2) under stirring, keeping it warm at 55-65°C for 20-40 minutes, heating it to 70-85°C and reacting at a constant temperature for 2-4 hours to obtain a high-temperature oil well cement retarder capable of inhibiting abnormal gelation. Its synthetic product can inhibit the "bulging" and "coring" phenomena of cement slurry in the temperature range of 120-150°C, and does not affect the strength development of cement stone. The comprehensive performance of cement slurry is good.

[0006] For example, the invention patent application, entitled "A Medium- and High-Temperature Oil Well Cement Retarder, Preparation Method, and Application," published on March 22, 2019, with application publication number CN109503760A, specifically discloses a medium- and high-temperature oil well cement retarder obtained by polymerizing itaconic acid, acrylic acid, and 2-acrylamido-2-methylpropanesulfonic acid in water in the presence of an organic phosphonate and an initiator. The synthesized product is suitable for use as a medium- and high-temperature oil well cement retarder in a temperature range of 65-135°C. It overcomes the problems of sensitive dosage of small molecule compounds, high initial consistency of carboxylic acid polymers, and abnormal gelation, and exhibits no inversion during application.

[0007] The aforementioned technical approaches primarily optimize the polymer's organic macromolecular structure, ignoring the impact of the cement matrix's mineral composition and batch composition fluctuations. This results in the admixture's inability to effectively adapt to different batches of cement slurry systems. Therefore, addressing the issue of abnormal cement slurry gelation requires addressing both the complexing and gelling effects of the polymer on cement hydration products and effectively suppressing abnormal slurry gelation when the cement matrix's mineral composition fluctuates, thereby ensuring stable control of the thickening performance of the ultra-high temperature cement slurry system. Summary of the Invention

[0008] To overcome the drawbacks and shortcomings of the aforementioned prior art, the present invention provides a material for preventing abnormal gelation in cement slurries, as well as its preparation method and application. This invention aims to address both the complexation and gelation effects of polymer macromolecules on cement hydration products and the problem of suppressing abnormal gelation in cement slurries when the mineral composition of the cement matrix fluctuates. The present invention's material for preventing abnormal gelation in cement slurries for ultra-deep wells (10,000 meters) is an inorganic material that not only ensures stable performance in ultra-high temperature environments but also exhibits excellent compatibility with cement matrix materials, high-temperature admixtures, and additives, resulting in a wide range of applications.

[0009] In order to solve the above problems in the prior art, the present invention is implemented through the following technical solutions.

[0010] A first aspect of the present invention provides a cementing slurry anti-abnormal gelling material, comprising the following components in parts by weight:

[0011] 40-60 parts of ulexite;

[0012] 20-40 parts of colemanite;

[0013] 10-20 parts of ulexite;

[0014] 5-15 parts of gallstones;

[0015] The chemical composition requirements of the abnormal gelling material for cementing slurry are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%;

[0016] The particle fineness requirements of the abnormal gelling prevention material of the cementing slurry are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0017] Further preferably, the purity of the ulexite is required to be ≥90wt.%, and the chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, and B2O3>38wt.%.

[0018] Further preferably, the purity of the colemanite is required to be ≥90wt.%, and the chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%.

[0019] Further preferably, the purity of the leucite is required to be ≥90wt.%, and the chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%.

[0020] Further preferably, the purity of the gallstone is required to be ≥90wt.%, and the chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0021] A second aspect of the present invention provides a method for preparing a cement slurry anti-abnormal gelling material, comprising the following steps:

[0022] S1. Evenly mix 40-60 parts of ulexite, 20-40 parts of colemanite, and 10-20 parts of leucite, and crush the mixture after even mixing, with a crushing ratio controlled at 40-70; grind the crushed mixture into a mixed fine material, with a crushing ratio controlled at 400-900; send the crushed mixed fine material to a high-temperature calcining furnace for calcination, with the calcination temperature controlled at 800° C.-1500° C.; after calcination, quickly cool the mixture to room temperature, with a cooling time controlled at 10-20 min; and obtain a Class A mixture after cooling;

[0023] S2. Mix the Class A mixture prepared in step S1 with 5 to 15 parts of gallstones, grind the mixture evenly, and obtain Class B mixture after grinding. The particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0024] S3, coating the Class B mixture, specifically, adding the Class B mixture into the coating solution, mixing evenly and reacting for a set time, and vacuum drying to obtain the cement slurry anti-abnormal gelling material.

[0025] Further preferably, the coating solution comprises the following components by mass ratio:

[0026] Anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = (55~70): (15~25): (5~10): (5~10): (5~10).

[0027] More preferably, the concentration of the plating solution is 55 wt.% to 85 wt.%.

[0028] More preferably, in step S3, the ratio of the type B mixture to the plating solution is 1:(5-20).

[0029] More preferably, in step S3, the reaction time is set to 5 to 35 minutes.

[0030] More preferably, in step S3, the vacuum drying temperature is 35°C to 55°C.

[0031] A third aspect of the present invention provides an application of an abnormal gelling material for cementing slurry in cementing slurry for ultra-deep wells of 10,000 meters.

[0032] Compared with the prior art, the beneficial technical effects brought about by the present invention are as follows:

[0033] The present invention's material for preventing abnormal gelation of cement slurries can be applied to cement slurries used in ultra-deep wells up to 10,000 meters, suppressing abnormal gelation in these wells. This material addresses the impact of fluctuations in cement mineral composition from batch to batch on abnormal gelation of cement slurries, based on the perspective of cement hydration products.

[0034] The solution is as follows: different batches of cement have different tricalcium aluminate contents in their mineral components, and thus different aluminum ion contents in the cement slurry. Tricalcium aluminate hydrates very quickly, quickly forming hydrated calcium aluminate gel products in the cement slurry, causing abnormal gelling phenomena such as thickening of the cement slurry. In addition, when the aluminum ion concentration in the cement slurry reaches a certain level, it will combine and cross-link with the calcium ions and the high molecular chains in the polymer admixture to form a mutually doped cross-linked network structure, resulting in abnormal gelling of the cement slurry (the thickening curve shows "bulging" and "core-encapsulation" phenomena). The abnormal gelling prevention material for cementing slurry of the present invention releases sulfate ions through a hydrolysis reaction, which react with aluminum ions and calcium ions under medium-high temperature hydrothermal conditions to form monosulfurized calcium sulfoaluminate. On the one hand, the aluminum ion content in the cement slurry is reduced, preventing the aluminum ions from forming a mutually doped cross-linked network structure with other ions and high molecular chains in the polymer admixture; on the other hand, the monosulfurized calcium sulfoaluminate is wrapped around the surface of tricalcium aluminate to prevent its rapid hydration, thereby inhibiting the rapid formation of hydrated calcium aluminate in the cement slurry, thereby preventing abnormal gelling of the cement slurry.

[0035] Therefore, no matter how the cement batches and their mineral components change, the main difference is the difference in the aluminum phase content in the cement components. This technical means solves the abnormal gelling effect of aluminum ions on cement slurry from the root, so that the anti-abnormal gelling material of the present invention can adapt to different batches of cement.

[0036] 2. The anti-abnormal gelling material for cementing slurry of the present invention can effectively inhibit the problem of abnormal gelling caused by complexation between admixtures and cement components. The working principle is as follows: high-temperature cementing slurry systems usually use polymer admixtures. The macromolecules in the admixtures compete for calcium ions in the cement slurry, and usually multiple polymer molecules chelate one calcium ion, thereby causing the long-chain macromolecular polymers to form a bridge network, resulting in abnormal gelling of the cement slurry. The abnormal gelling prevention material for cementing slurry of the present invention releases borate ions and copper ions through a hydrolysis reaction. On the one hand, the copper ions deprive the calcium ions chelated in the polymer molecules. Since the relative atomic mass of copper ions is larger than that of calcium ions, the copper ions carry the chelated polymer molecules downward in the cement slurry, thereby separating multiple polymer molecules. On the other hand, the borate ions also rob the calcium ions chelated in the polymer molecules, preferentially forming calcium borate. The calcium borate is quickly coated on the surfaces of tricalcium silicate and dicalcium silicate, preventing them from undergoing hydration reactions, thereby prolonging the thickening time of the cement slurry. At this time, the deprived polymer molecules are uniformly dispersed in the cement slurry in a flowing state, thereby inhibiting the formation of a bridging network of high-molecular-weight long-chain polymers, thereby preventing abnormal gelling of the cement slurry.

[0037] 3. In the present invention, the chemical composition of the material for preventing abnormal gelling of cement slurry is limited. Only the gelling material that meets this chemical composition can ensure the performance of the material for preventing abnormal gelling of cement slurry. This chemical composition is specifically aimed at the chemical component ratio involved in the abnormal gelling phenomenon of cement slurry. Each component can exert the best performance of the material only within this limited range.

[0038] 4. The present invention further limits the particle size of the material used to prevent abnormal gelling of cement slurry. If the material is too fine, it will affect the compatibility of the material with other materials, for example, forming abnormal gelling or performance conflicts with other materials. In addition, if the material is too fine, its solubility will be accelerated, and excessive water absorption will easily cause the cement slurry to thicken, which is not conducive to construction safety. ② If the material is too coarse, its solubility will deteriorate, and the material's performance will not be able to be exerted in time. In addition, if the material is too coarse, it will also cause sedimentation, thereby affecting the stability of the material. Therefore, as long as the particle fineness requirements exceed this range, the optimal performance of the material cannot be exerted, so it is necessary to limit the fineness of the material of this application.

[0039] 5. The present invention's cementing slurry anti-abnormal gelling material is an inorganic material that has no negative impact on the engineering properties of the cement slurry or the mechanical properties of the cement paste. It not only ensures stable performance and resistance to failure in ultra-high temperature environments, but also exhibits excellent compatibility with cement substrates, high-temperature admixtures, and additives. Furthermore, the present invention's anti-abnormal gelling material contains a portion of tricalcium silicate and dicalcium silicate. After the cement slurry solidifies to form cement paste, the residual tricalcium silicate and dicalcium silicate in the anti-abnormal gelling material fill the pores of the cement paste and slowly hydrate. The resulting hydrated calcium silicate gel continuously fills the tiny pores in the cement paste, thereby increasing the density of the cement paste and beneficially improving the compressive strength of the cement paste at high temperatures.

[0040] 6. The present invention further defines the purity and chemical composition requirements for each component. By further defining and optimizing the purity and chemical composition of each component, it is ensured that the cementing slurry anti-abnormal gelling material obtained after compounding the components meets the chemical composition requirements and achieves the material's optimal performance. Furthermore, further defining the purity and chemical composition requirements for each component can increase the success rate of compounding the cementing slurry anti-abnormal gelling material, ensuring that the resulting material meets the chemical composition requirements and achieves the material's optimal performance.

[0041] 7. When preparing the fixed cement slurry anti-abnormal gelling material, the Class B mixture is subjected to a coating treatment. The purpose is: the sulfate component in the Class B mixture will undergo a hydrolysis reaction during the cement slurry preparation process, and the released sulfate ions will react with the aluminum ions and calcium ions in the cement slurry to form ettringite. Under low temperature conditions (generally below 70°C), ettringite is relatively stable. During the formation process, a large amount of water is consumed. At the same time, the needle-shaped ettringite intersperses and intertwines with each other, which can easily cause the cement slurry to thicken rapidly in a short period of time (mainly manifested in the "bulging" phenomenon on the cementing cement slurry thickening curve), seriously affecting the safety of cementing construction. Therefore, a coating method is adopted to form a plastic resin protective film on the surface of the Class B mixture particles. Under low temperature conditions, it can effectively prevent the sulfate component in the Class B mixture from reacting with water, reducing the concentration of sulfate ions in the cement slurry, thereby preventing the formation of ettringite. At this time, the Class B mixture is evenly dispersed in the cement slurry as a filling material. As the temperature rises during the grouting process, the resin protective film begins to decompose (generally above 70°C), and the Class B mixture begins to hydrolyze. Although the sulfate ion concentration in the cement slurry will increase at this time, the generated ettringite is extremely unstable in medium and high temperature environments and will decompose rapidly, which will not cause the cementing cement slurry to thicken rapidly, thereby ensuring the smooth progress of cementing construction.

[0042] 8. The coating solution used in preparing the abnormal gelling prevention material for cementing slurries in the present invention can be any conventional coating solution, as long as it can form a plastic resin protective film on the surface of the Class B mixture particles and the resin protective film can decompose above 70°C. As a preferred embodiment of the present invention, the coating solution used in the present invention comprises anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate, and diethyl phthalate, compounded in a predetermined ratio. The constituent monomers and ratios are optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a graph showing the thickening curve test results of the S1# cement slurry system provided in Example 1 of the present invention;

[0044] Figure 2 This is a graph showing the thickening curve test results of the D1# cement slurry system provided in Comparative Example 1 of the present invention;

[0045] Figure 3 This is a graph showing the thickening curve test results of the S2# cement slurry system provided in Example 2 of the present invention;

[0046] Figure 4 This is a graph showing the thickening curve test results of the D2# cement slurry system provided in Comparative Example 2 of the present invention;

[0047] Figure 5 This is a graph showing the thickening curve test results of the S3# cement slurry system provided in Example 3 of the present invention;

[0048] Figure 6 This is a graph showing the thickening curve test results of the D3# cement slurry system provided in Comparative Example 3 of the present invention;

[0049] Figure 7 This is a graph showing the thickening curve test results of the S4# cement slurry system provided in Example 4 of the present invention;

[0050] Figure 8 This is a graph showing the thickening curve test results of the D4# cement slurry system provided in Comparative Example 4 of the present invention;

[0051] Figure 9 This is a graph showing the thickening curve test results of the S5# cement slurry system provided in Example 5 of the present invention;

[0052] Figure 10 This is a graph showing the thickening curve test results of the D5# cement slurry system provided in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions of the present invention in conjunction with specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0054] The following examples all prepare cement slurries in accordance with GB / T 19139-2012. In the cement slurry systems listed in the examples, the cement used is Jiahua G-grade high-resistance cement, quartz sand and metakaolin can be purchased from the market, the high-temperature stabilizer is a mixture of ultrafine material and clay, the high-temperature fluid loss additive is an AMPS-VP-AM-AA tetrapolymer, and the high-temperature retarder is an AMPS-itaconic acid copolymer.

[0055] Example 1

[0056] As a preferred embodiment of the present invention, this embodiment discloses a cementing slurry anti-abnormal gelling material, which includes the following components by weight: 60 parts of ulexite, 25 parts of colemanite, 10 parts of leonite and 5 parts of chalcanthite.

[0057] In this embodiment, the above-mentioned cement slurry abnormal gelling prevention material is prepared by the following preparation method:

[0058] S1. 60 parts by weight of ulexite, 25 parts by weight of colemanite and 10 parts by weight of leucite are mixed uniformly, and then crushed by a grinding mill with a crushing ratio controlled at 60; the crushed mixture is sent to a ball mill and ground into a mixed fine material with a crushing ratio controlled at 700; the crushed mixed fine material is then sent to a high-temperature calcining furnace for calcination with a calcination temperature controlled at 1350° C. After calcination, the mixture is rapidly cooled to room temperature by a cooler with a cooling time controlled at 20 min to obtain a Class A mixture.

[0059] S2. The Class A mixture prepared in step S1 is mixed evenly with 5 parts by weight of gallstones, and then sent to a ball mill for grinding to obtain a Class B mixture after fine grinding; the particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0060] S3. The Class B mixture is subjected to a coating treatment. Specifically, 100 parts by weight of the Class B mixture is added to 500 parts by weight of a coating solution having a concentration of 80 wt.%, mixed evenly, and reacted for 5 minutes. The mixture is then placed in a vacuum drying oven at 35°C and dried to obtain the cement slurry anti-abnormal gelling material, referred to as "S1# material".

[0061] The chemical composition requirements of the above-mentioned "S1# material" are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%.

[0062] As an example, to meet the chemical composition requirements of the above-mentioned "S1# material", the purity and chemical composition of ulexite, colemanite, leonite, and chalcanthite can be limited, that is, the selection of ulexite, colemanite, leonite, and chalcanthite materials. Specifically, the purity requirement of ulexite is ≥90wt.%, and its chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, B2O3>38wt.%; the purity requirement of colemanite is ≥90wt.%, and its chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%; the purity requirement of leonite is ≥90wt.%, and its chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%; the purity requirement of chalcanthite is ≥90wt.%, and its chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0063] In this embodiment, when preparing "S1# material", the coating solution used is composed of anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate and diethyl phthalate, and the mass ratio is anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = 65:15:10:5:5.

[0064] The formula of the "S1# cement slurry system" that matches the "S1# material" is: 100 parts by weight of Grade G high-resistance cement + 10 parts by weight of "S1# material" + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-grade terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0065] Example 2

[0066] As another preferred embodiment of the present invention, this embodiment discloses a cementing slurry anti-abnormal gelling material, which includes the following components in parts by weight: 40 parts of ulexite, 35 parts of colemanite, 20 parts of leucite and 5 parts of chalcanthite.

[0067] In this embodiment, the above-mentioned cement slurry anti-abnormal gelling material is prepared by the following preparation method:

[0068] S1. 40 parts by weight of ulexite, 35 parts by weight of colemanite and 20 parts by weight of leucite are mixed uniformly, and then crushed by a grinding mill with a crushing ratio controlled at 65; the crushed mixture is sent to a ball mill and ground into a mixed fine material with a crushing ratio controlled at 750; the crushed mixed fine material is then sent to a high-temperature calcining furnace for calcination at a calcination temperature of 1200° C. After calcination, the mixture is rapidly cooled to room temperature by a cooler with a cooling time controlled at 15 min to obtain a Class A mixture.

[0069] S2. The Class A mixture prepared in step S1 is mixed evenly with 5 parts by weight of gallstones, and then sent to a ball mill for grinding to obtain a Class B mixture after fine grinding; the particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0070] S3. The Class B mixture is subjected to a coating treatment, specifically, 100 parts by weight of the Class B mixture is added to 1000 parts by weight of a 75 wt.% coating solution, mixed evenly and reacted for 10 minutes, and then placed in a 40°C vacuum drying oven for drying to obtain the cementing slurry anti-abnormal gelling material, referred to as "S2# material".

[0071] The chemical composition requirements of the above-mentioned "S2# material" are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%.

[0072] As an example, in order to meet the chemical composition requirements of the above-mentioned "S2# material", the purity and chemical composition of ulexite, colemanite, leucite, and chalcanthite can be limited, that is, the selection of ulexite, colemanite, leucite, and chalcanthite materials. Specifically, the purity requirement of ulexite is ≥90wt.%, and its chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, B2O3>38wt.%; the purity requirement of colemanite is ≥90wt.%, and its chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%; the purity requirement of leucite is ≥90wt.%, and its chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%; the purity requirement of chalcanthite is ≥90wt.%, and its chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0073] In this embodiment, when preparing "S2# material", the coating solution used is composed of anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate and diethyl phthalate, and the mass ratio is anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = 55:20:8:10:7.

[0074] The formula of the "S2# cement slurry system" that matches the "S2# material" is: 100 parts by weight of Grade G high-resistance cement + 10 parts by weight of "S2# material" + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-temperature terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0075] Example 3

[0076] As another preferred embodiment of the present invention, this embodiment discloses a cementing slurry anti-abnormal gelling material, which includes the following components in parts by weight: 40 parts of ulexite, 35 parts of colemanite, 10 parts of leonite and 15 parts of chalcanthite.

[0077] In this embodiment, the above-mentioned cement slurry anti-abnormal gelling material is prepared by the following preparation method:

[0078] S1. 40 parts by weight of ulexite, 35 parts by weight of colemanite and 10 parts by weight of leonidite are mixed uniformly, and then crushed by a grinding mill with a crushing ratio controlled at 70; the crushed mixture is sent to a ball mill and ground into a mixed fine material with a crushing ratio controlled at 800; the crushed mixed fine material is then sent to a high-temperature calcining furnace for calcination at a calcination temperature of 1000° C. After calcination, the mixture is rapidly cooled to room temperature by a cooler with a cooling time controlled at 10 min to obtain a Class A mixture.

[0079] S2. The Class A mixture prepared in step S1 is mixed evenly with 15 parts by weight of gallstones, and then sent to a ball mill for grinding to obtain a Class B mixture after fine grinding; the particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0080] S3. The Class B mixture is subjected to a coating treatment. Specifically, 100 parts by weight of the Class B mixture is added to 1500 parts by weight of a 70 wt.% coating solution, mixed evenly and reacted for 15 minutes, and then placed in a 45°C vacuum drying oven for drying to obtain the cementing slurry anti-abnormal gelling material, referred to as "S3# material".

[0081] The chemical composition requirements of the above-mentioned "S3# material" are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%.

[0082] As an example, to meet the chemical composition requirements of the above-mentioned "S3# material", the purity and chemical composition of ulexite, colemanite, leucite, and chalcanthite can be limited, that is, the selection of ulexite, colemanite, leucite, and chalcanthite materials. Specifically, the ulexite purity requirement is ≥90wt.%, and its chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, B2O3>38wt.%; the colemanite purity requirement is ≥90wt.%, and its chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%; the leucite purity requirement is ≥90wt.%, and its chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%; the chalcanthite purity requirement is ≥90wt.%, and its chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0083] In this embodiment, when preparing "S3# material", the coating solution used is composed of anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate and diethyl phthalate, and the mass ratio is anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = 55:25:10:5:5.

[0084] The formula of the "S3# cement slurry system" that matches the "S3# material" is: 100 parts by weight of Grade G high-resistance cement + 10 parts by weight of "S3# material" + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-temperature terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0085] Example 4

[0086] As another preferred embodiment of the present invention, this embodiment discloses a cementing slurry anti-abnormal gelling material, which includes the following components in parts by weight: 50 parts of ulexite, 20 parts of colemanite, 15 parts of leonite and 15 parts of chalcanthite.

[0087] In this embodiment, the above-mentioned cement slurry anti-abnormal gelling material is prepared by the following preparation method:

[0088] S1. 50 parts by weight of ulexite, 20 parts by weight of colemanite and 15 parts by weight of leonidite are mixed uniformly, and then crushed by a grinding mill with a crushing ratio controlled at 40; the crushed mixture is sent to a ball mill and ground into a mixed fine material with a crushing ratio controlled at 400; the crushed mixed fine material is then sent to a high-temperature calcining furnace for calcination at a calcination temperature of 800°C. After calcination, the mixture is rapidly cooled to room temperature by a cooler with a cooling time controlled at 10 min to obtain a Class A mixture.

[0089] S2. The Class A mixture prepared in step S1 is mixed evenly with 15 parts by weight of gallstones, and then sent to a ball mill for grinding to obtain a Class B mixture after fine grinding; the particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0090] S3. The Class B mixture is subjected to a coating treatment. Specifically, 100 parts by weight of the Class B mixture is added to 2000 parts by weight of a 55 wt.% coating solution, mixed evenly and reacted for 25 minutes, and then placed in a 50°C vacuum drying oven for drying to obtain the cement slurry anti-abnormal gelling material, referred to as "S4# material".

[0091] The chemical composition requirements of the above-mentioned "S4# material" are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%.

[0092] As an example, to meet the chemical composition requirements of the above-mentioned "S4# material", the purity and chemical composition of ulexite, colemanite, leucite, and chalcanthite can be limited, that is, the selection of ulexite, colemanite, leucite, and chalcanthite materials. Specifically, the purity requirement of ulexite is ≥90wt.%, and its chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, B2O3>38wt.%; the purity requirement of colemanite is ≥90wt.%, and its chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%; the purity requirement of leucite is ≥90wt.%, and its chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%; the purity requirement of chalcanthite is ≥90wt.%, and its chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0093] In this embodiment, when preparing "S4# material", the coating solution used is composed of anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate and diethyl phthalate, and the mass ratio is anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = 70:15:5:5:5.

[0094] The formula of the "S4# cement slurry system" that matches the "S4# material" is: 100 parts by weight of Grade G high-resistance cement + 10 parts by weight of "S4# material" + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-grade terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0095] Example 5

[0096] As another preferred embodiment of the present invention, this embodiment discloses a cementing slurry anti-abnormal gelling material, which includes the following components in parts by weight: 40 parts of ulexite, 40 parts of colemanite, 10 parts of leonite and 10 parts of chalcanthite.

[0097] In this embodiment, the above-mentioned cement slurry abnormal gelling prevention material is prepared by the following preparation method:

[0098] S1. 40 parts by weight of ulexite, 40 parts by weight of colemanite and 10 parts by weight of leonidite are mixed uniformly, and then crushed by a grinding mill with a crushing ratio controlled at 50; the crushed mixture is sent to a ball mill and ground into a mixed fine material with a crushing ratio controlled at 900; the crushed mixed fine material is then sent to a high-temperature calcining furnace for calcination at a calcination temperature of 1500°C. After calcination, the mixture is rapidly cooled to room temperature by a cooler with a cooling time controlled at 20 min to obtain a Class A mixture.

[0099] S2. The Class A mixture prepared in step S1 is mixed evenly with 10 parts by weight of gallstones, and then sent to a ball mill for grinding to obtain a Class B mixture after fine grinding; the particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm.

[0100] S3. The Class B mixture is subjected to a coating treatment, specifically, 100 parts by weight of the Class B mixture is added to 1500 parts by weight of a coating solution with a concentration of 85 wt.%, mixed evenly and reacted for 35 minutes, and then placed in a 55°C vacuum drying oven for drying to obtain the cementing slurry anti-abnormal gelling material, referred to as "S5# material".

[0101] The chemical composition requirements of the above-mentioned "S5# material" are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%.

[0102] As an example, to meet the chemical composition requirements of the above-mentioned "S5# material", the purity and chemical composition of ulexite, colemanite, leucite, and chalcanthite can be limited, that is, the selection of ulexite, colemanite, leucite, and chalcanthite materials. Specifically, the ulexite purity requirement is ≥90wt.%, and its chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, B2O3>38wt.%; the colemanite purity requirement is ≥90wt.%, and its chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%; the leucite purity requirement is ≥90wt.%, and its chemical composition requirements are: Na2O>22wt.%, SiO2>42wt.%, B2O3>24wt.%; the chalcanthite purity requirement is ≥90wt.%, and its chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

[0103] In this embodiment, when preparing "S5# material", the coating solution used is composed of anhydrous ethanol, phenolic resin, polymethyl methacrylate, dimethyl phthalate and diethyl phthalate, and the mass ratio is anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = 60:15:8:7:10.

[0104] The formula of the "S5# cement slurry system" that matches the "S5# material" is: 100 parts by weight of Grade G high-resistance cement + 10 parts by weight of "S5# material" + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-temperature terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0105] Comparative Example 1

[0106] Compared with Example 1, the cement slurry system in this comparative example does not add "S1# material", and the matching "D1# cement slurry system" formula is: 100 parts by weight of G-grade high-resistance cement + 40 parts by weight of quartz sand + 9 parts by weight of relatively high-temperature terroir + 3 parts by weight of high-temperature stabilizer (ultrafine material and clay-like substance) + 6 parts by weight of high-temperature fluid loss additive (AMPS-VP-AM-AA tetrapolymer) + 2 parts by weight of high-temperature retarder (AMPS-itaconic acid copolymer) + 65 parts by weight of water.

[0107] Comparative Example 2

[0108] Compared with Example 2, this comparative example does not undergo the calcination and cooling process, and the other conditions are the same. The abnormal gelling material for ultra-deep well cementing slurry prepared in this comparative example is referred to as "D2# material".

[0109] The "D2# cement slurry system" that matches the "D2# material" is the same as the "S2# cement slurry system".

[0110] Comparative Example 3

[0111] Compared with Example 3, this comparative example does not undergo coating treatment, and all other conditions are the same. The abnormal gelling prevention material for cement slurry used in ultra-deep wells with a depth of 10,000 meters prepared in this comparative example is referred to as "D3# material".

[0112] The "D3# cement slurry system" that matches the "D3# material" is the same as the "S3# cement slurry system".

[0113] Comparative Example 4

[0114] Compared to Example 4, the composition of the abnormal-prevention cementing material in this comparative example is modified. It now includes the following components, by weight: 20 parts ulexite, 10 parts colemanite, 5 parts leucite, and 65 parts chollasite. The chemical composition of this abnormal-prevention cementing material exceeds the specified range in Example 4. All other conditions remain the same. The abnormal-prevention cementing material for cement slurry used in ultra-deep wells with a depth of 10,000 meters, prepared in this comparative example, is referred to as "D4# material."

[0115] The "D4# cement slurry system" that matches the "D4# material" is the same as the "S4# cement slurry system".

[0116] Comparative Example 5

[0117] Compared to Example 5, the particle fineness of the abnormal-prevention cementing material in this comparative example has changed, exceeding the specified range in Example 5. All other conditions remain the same. The abnormal-prevention cementing material for cement slurries used in ultra-deep wells with a depth of 10,000 meters, produced in this comparative example, is referred to as "D5# material."

[0118] The "D5# cement slurry system" that matches the "D5# material" is the same as the "S5# cement slurry system".

[0119] According to GB / T 19139-2012 standard, the engineering properties and mechanical properties of the cement slurry systems obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were tested. The test results are shown in Table 1.

[0120] Table 1 Test results of engineering properties and mechanical properties of high-temperature cementing cement

[0121]

[0122] Note: The curing conditions for the upper and lower density difference experiment are: 230℃×20.7MPa×48h, the free liquid content test conditions are: 90℃×0.1MPa×2h, the API water loss test conditions are: 185℃×6.9MPa×30min, the cement paste compressive strength curing conditions are: 230℃×20.7MPa, and the thickening test conditions are: 185℃×100MPa×100min.

[0123] The engineering performance test results in Table 1 demonstrate that the cementing slurry systems prepared in Examples 1-5 of the present invention exhibit excellent fluidity, zero free liquid content, low API water loss, excellent settling stability, and no abnormal gelling during thickening. These advantages all meet industry standards for high-temperature cement cementing. Furthermore, the present invention's anti-abnormal gelling material for ultra-deep well cementing slurries exhibits excellent compatibility with high-temperature stabilizers, high-temperature fluid loss additives, and high-temperature retarders. Compared to a blank sample (Comparative Example 1), the present invention's anti-abnormal gelling material exhibits minimal impact on the fluidity, free liquid content, API water loss, and settling stability of the cement slurry system. Furthermore, it significantly reduces abnormal gelling during thickening, demonstrating its suitability for high-temperature cement slurry applications.

[0124] The mechanical property test results in Table 1 show that the cement paste formed by curing the cement slurry systems prepared in Examples 1 to 5 of the present invention has the advantages of high compressive strength and no decay at high temperatures. Compared with the blank sample (Comparative Example 1), the compressive strength of the cement paste at 2 days and 7 days is improved, indicating that the anti-abnormal cementing material of the present invention can increase the density of the cement paste and has a beneficial effect on the compressive strength of the cement paste at high temperatures.

[0125] Refer to the instruction manual Figure 1 and attached Figure 2As shown in the figures, compared with Example 1, the cementing cement slurry system prepared in Comparative Example 1 exhibited severe abnormal gelation during the thickening process, specifically manifested as: a linear mutation value of the consistency exceeding 10Bc (obvious bulging appeared on the curve), and severe fluctuations in the temperature curve (obvious core coating appeared on the thickening blades). This indicates that the cement slurry system without the addition of the anti-abnormal gelling material of the present invention is difficult to ensure stable thickening performance of the high-temperature cement slurry, thereby affecting the safety of cementing construction.

[0126] Refer to the instruction manual Figure 3 and attached Figure 4 As shown in the figure, compared with Example 2, the cementing slurry system prepared in Comparative Example 2 exhibited severe abnormal gelation during the thickening process, specifically manifested as: a linear mutation value of the consistency exceeding 10Bc (obvious bulging appeared on the curve), and severe fluctuations in the temperature curve (obvious core coating appeared on the thickening blades). This indicates that the anti-abnormal gelation material prepared without the calcination and cooling processes cannot solve the problem of abnormal gelation during thickening of high-temperature cement slurry. This further illustrates the importance of each preparation process link of the anti-abnormal gelation material in ensuring the stable thickening performance of high-temperature cement slurry.

[0127] Refer to the instruction manual Figure 5 and attached Figure 6 As shown, compared to Example 3, the cementing slurry system produced in Comparative Example 3 exhibited severe abnormal gelation during the thickening process. Specifically, the linear viscosity change exceeded 10 Bc (visible bulging appeared on the curve) in the early thickening phase, while other phenomena remained normal (normal temperature curve and no core encapsulation on the thickening blades). This indicates that uncoated anti-abnormal gelling materials cannot address the bulging problem of high-temperature cement slurry thickening. This is because the sulfate components in uncoated anti-abnormal gelling materials undergo hydrolysis. The released sulfate ions react with aluminum and calcium ions in the cement slurry at low temperatures to form stable ettringite, which consumes a large amount of water. Furthermore, the needle-shaped ettringite intersperses and intersects, easily causing rapid thickening of the cement slurry in a short period of time, seriously affecting cementing operation safety. This demonstrates that coating treatment is crucial for ensuring stable thickening performance of high-temperature cement slurries using anti-abnormal gelling materials.

[0128] Refer to the instruction manual Figure 7 and attached Figure 8As shown, compared with Example 4, the cementing slurry system prepared in Comparative Example 4 exhibited severe abnormal gelation during the thickening process, specifically manifested as: a linear mutation value of the consistency exceeding 10Bc (obvious bulging appeared on the curve), and severe fluctuations in the temperature curve (obvious core formation appeared on the thickening blades). This indicates that when the chemical composition of the anti-abnormal gelation material exceeds the specified range of the present invention, it cannot solve the problem of abnormal gelation during thickening of high-temperature cement slurry. Furthermore, it is shown that only by meeting the chemical composition requirements of the anti-abnormal gelation material of the present invention can the corresponding performance be achieved and the problem raised in the present application be solved. This is because the anti-abnormal gelation material of the present invention is a chemical component ratio specifically designed to address the abnormal gelation phenomenon of cement slurry, and each component can only exert its optimal performance within this specified range.

[0129] Refer to the instruction manual Figure 9 and attached Figure 10 As shown, compared with Example 5, the cementing slurry system prepared in Comparative Example 5 exhibited severe abnormal gelation during the thickening process, specifically manifested as: a linear mutation value of the consistency exceeding 10 Bc (obvious bulging appeared on the curve), and severe fluctuations in the temperature curve (obvious core coating appeared on the thickening blade). This indicates that when the particle fineness of the anti-abnormal gelling material exceeds the specified range of the present invention, it cannot solve the problem of abnormal gelation during thickening of high-temperature cement slurry. Furthermore, it is shown that only by meeting the particle fineness requirements of the anti-abnormal gelling material of the present invention can the corresponding performance be achieved and the problem raised in the present application be solved. This is because when the anti-abnormal gelling material is too fine, it will lead to abnormal gelation and performance conflicts with other admixtures. In addition, excessively fine materials will accelerate their solubility, and excessive water absorption will easily cause the cement slurry to thicken, which is not conducive to construction safety. When the anti-abnormal gelling material is too coarse, its solubility will deteriorate, and the material's performance cannot be fully exerted in a timely manner. In addition, excessively coarse materials will cause sedimentation, thereby affecting the stability of the material. Therefore, as long as the particle fineness requirement exceeds this range, the performance of the material will be hindered, so it is necessary to limit the fineness of the material of this application.

[0130] Example 6

[0131] As another preferred embodiment of the present invention, this embodiment discloses the application of the cement slurry anti-abnormal gelling material described in Examples 1 through 5 above to cement slurries used in ultra-deep wells with depths exceeding 10,000 meters. This material is used to inhibit abnormal gelling of cement slurries in ultra-deep wells with depths exceeding 10,000 meters. This material addresses the impact of abnormal gelling on cement slurries caused by fluctuations in cement mineral composition across different batches, based on the perspective of cement hydration products.

[0132] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention and are intended to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention. In other words, any changes or refinements made to the main design concept and spirit of the present invention that have no substantive significance, provided that the technical problems they solve are still consistent with those of the present invention, should be included in the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention to other related technical fields should also be included in the patent protection scope of the present invention.

Claims

1. Cementing slurry anti-abnormal gelling material, characterized by: It comprises the following components in parts by weight: 40-60 parts of ulexite; 20-40 parts of colemanite; 10-20 parts of ulexite; 5-15 parts of gallstones; The chemical composition requirements of the cementing cement slurry anti-abnormal gelling material are: 37wt.%<B2O3≤55wt.%, 11wt.%<CaO≤21wt.%, 5wt.%<SiO2≤13wt.%, 6wt.%<Na2O≤12wt.%, 1wt.%<SO3≤6wt.%, 1wt.%<CuO≤6wt.%, and the sum of the mass percentages of each chemical component is 100wt.%; the particle fineness requirements of the cementing cement slurry anti-abnormal gelling material are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm; The method for preparing the abnormal gelling prevention material for cementing slurry comprises the following steps: S1. Evenly mix 40-60 parts of ulexite, 20-40 parts of colemanite, and 10-20 parts of leucite, and crush the mixture after even mixing, with a crushing ratio controlled at 40-70; grind the crushed mixture into a mixed fine material, with a crushing ratio controlled at 400-900; send the crushed mixed fine material to a high-temperature calcining furnace for calcination, with the calcination temperature controlled at 800° C.-1500° C.; after calcination, quickly cool the mixture to room temperature, with a cooling time controlled at 10-20 min; and obtain a Class A mixture after cooling; S2. Mix the Class A mixture prepared in step S1 with 5 to 15 parts of gallstones, grind the mixture evenly, and obtain Class B mixture after grinding. The particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm. S3, coating the Class B mixture, specifically, adding the Class B mixture into the coating solution, mixing evenly and reacting for a set time, and vacuum drying to obtain the cement slurry anti-abnormal gelling material.

2. The abnormal gelling prevention material for cement slurry according to claim 1, characterized in that: The purity of the ulexite is required to be ≥90wt.%, and the chemical composition requirements are: Na2O>6wt.%, CaO>12wt.%, and B2O3>38wt.%.

3. The abnormal gelling prevention material for cement slurry according to claim 1, characterized in that: The purity of the colemanite is required to be ≥90wt.%, and the chemical composition requirements are: CaO>18wt.%, B2O3>33wt.%.

4. The abnormal gelling prevention material for cementing slurry according to claim 1, characterized in that: The purity of the gallstone is required to be ≥90wt.%, and the chemical composition requirements are: CuO>28wt.%, SO3>28wt.%.

5. The method for preparing the abnormal gelling prevention material for cementing slurry according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Evenly mix 40-60 parts of ulexite, 20-40 parts of colemanite, and 10-20 parts of leucite, and crush the mixture after even mixing, with a crushing ratio controlled at 40-70; grind the crushed mixture into a mixed fine material, with a crushing ratio controlled at 400-900; send the crushed mixed fine material to a high-temperature calcining furnace for calcination, with the calcination temperature controlled at 800° C.-1500° C.; after calcination, quickly cool the mixture to room temperature, with a cooling time controlled at 10-20 min; and obtain a Class A mixture after cooling; S2. Mix the Class A mixture prepared in step S1 with 5 to 15 parts of gallstones, grind the mixture evenly, and obtain Class B mixture after grinding. The particle fineness requirements of the Class B mixture are Dx(10)≤5μm, Dx(50)≤14μm, and Dx(90)≤30μm. S3, coating the Class B mixture, specifically, adding the Class B mixture into the coating solution, mixing evenly and reacting for a set time, and vacuum drying to obtain the cement slurry anti-abnormal gelling material.

6. The method for preparing the abnormal gelling prevention material for cementing slurry according to claim 5, characterized in that: The coating solution comprises the following components by mass ratio: Anhydrous ethanol: phenolic resin: polymethyl methacrylate: dimethyl phthalate: diethyl phthalate = (55~70): (15~25): (5~10): (5~10): (5~10).

7. The method for preparing the abnormal gelling prevention material for cementing slurry according to claim 5 or 6, characterized in that: The concentration of the plating solution is 55 wt.% to 85 wt.%.

8. The method for preparing the abnormal gelling prevention material for cementing slurry according to claim 5 or 6, characterized in that: In step S3, the ratio of the type B mixture to the coating solution is 1:(5-20) in parts by weight.

9. The method for preparing the abnormal gelling prevention material for cementing slurry according to claim 5 or 6, characterized in that: In step S3, the reaction time is set to 5 to 35 minutes.

10. The method for preparing the abnormal gelling prevention material for cementing slurry according to claim 5 or 6, characterized in that: In step S3, the vacuum drying temperature is 35°C to 55°C.

11. Use of the abnormal gelling material for cement slurry according to any one of claims 1 to 4 in cement slurry for ultra-deep wells with a depth of 10,000 meters.

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