Cement paste system for deepwater hydrate layer well cementation and preparation method of cement paste system

Abstract

The invention discloses a cement paste system for deepwater hydrate layer well cementation and a preparation method thereof, and belongs to the technical field of oil exploitation well cementation. The cement slurry system for well cementation of the deepwater hydrate layer comprises the following components in parts by weight: 59-77 wt.% of G-grade oil well cement and 2 wt.% of micro silicon; 10 to 15 wt.% of a low hydration heat cementing material; 3 to 5 wt.% of a density reducing material; 1-3 wt.% of a suspension stabilizing material; 5-10 wt.% of a heat conduction enhanced phase change temperature control material; 1-3 wt.% of an early strength agent; 0.5 to 1 wt.% of a dispersant; and 0.5-2 wt.% of a fluid loss agent. According to the cement paste system, the key technical problems in deepwater hydrate layer well cementation are successfully solved by effectively controlling hydration heat and temperature distribution, hydrate decomposition can be prevented to the maximum extent in the well cementation process, and shaft integrity and construction safety are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil extraction cementing, in particular to a cement slurry system for deepwater hydrate layer cementing and a preparation method thereof. BACKGROUND

[0002] Natural gas hydrate, also known as combustible ice, is a crystalline substance similar to ice formed by natural gas and water under high pressure and low temperature. It is widely distributed in deep-sea sediments and permafrost on land, with characteristics of shallow burial, wide distribution and large resource potential, and has attracted great attention from governments and scientific communities around the world. In the exploitation of deepwater oil and gas resources, deepwater cementing technology is an important prerequisite for ensuring economic and safety. However, when cementing operations are carried out on the deepwater surface hydrate layer, the conventional cement slurry system may release a large amount of heat due to hydration reaction, which may cause the hydrate layer to decompose and thus lead to channeling risk.

[0003] To achieve safe and efficient exploitation of oil and gas resources below the deepwater hydrate layer, the key is to ensure the stability of the hydrate layer during drilling and production, and to avoid its decomposition. However, the hydration heat release characteristics of traditional cement slurry may destroy the stability of the hydrate, affect the sealing performance of the cement sheath and the overall cementing quality, making it difficult to meet the needs of deepwater hydrate layer cementing.

[0004] Therefore, it is urgent to develop a low-density cement slurry system suitable for deepwater natural gas hydrate formation to effectively reduce hydration heat release, prevent natural gas hydrate decomposition, and ensure the safety and quality of cementing operations. SUMMARY

[0005] One of the purposes of the present application is to provide a cement slurry system for deepwater hydrate layer cementing, which has low hydration temperature rise and hydration heat release, can effectively reduce hydration heat release, prevent natural gas hydrate decomposition, and ensure the safety and quality of cementing operations.

[0006] The second purpose of the present application is to provide a preparation method of the cement slurry system for deepwater hydrate layer cementing.

[0007] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0008] The present application provides a cement slurry system for deepwater hydrate layer cementing, which comprises the following components by weight: G-grade oil well cement: 59-77 wt.%, microsilica: 2 wt.%, low hydration heat gelling material: 10-15 wt.%, density reducing material: 3-5 wt.%, suspension stabilizing material: 1-3 wt.%, heat-conducting enhanced phase change temperature control material: 5-10 wt.%, early strength agent: 1-3 wt.%, dispersant: 0.5-1 wt.%, and fluid loss additive: 0.5-2 wt.%.

[0009] In some embodiments of the present application, the micro-silicon powder has a particle size less than 10 microns.

[0010] In some embodiments of the present application, the low water heat cementing material is a mixture of metakaolin and lithium slag in a mass ratio of 3:1 to 3; preferably 3:2.

[0011] Preferably, the particle size of the metakaolin and the lithium slag is less than 45 microns.

[0012] In some embodiments of the present application, the density-reducing material is fly ash hollow microsphere with a particle size less than 20 microns and a density of 0.65 to 0.80 g / cm 3 , preferably 0.72 g / cm 3 .

[0013] In some embodiments of the present application, the suspension stabilizing material is a mixture of ultra-fine dolomite powder and ultra-fine aluminum silicate in a mass ratio of 10 to 20:1, preferably 15:1.

[0014] Preferably, the particle size of the ultra-fine dolomite and the ultra-fine aluminum silicate is less than 5 microns.

[0015] In some embodiments of the present application, the early strength agent is a mixture of triisopropanolamine, sodium salt of nitrilotriacetic acid, and sodium sulfate in a mass ratio of 1:2:4.

[0016] The dispersing agent is a polycarboxylic acid.

[0017] The fluid loss additive is a 2-acrylamide-2-methylpropanesulfonic acid (AMPS) polymer.

[0018] The heat-conducting enhanced phase change temperature control material is a mixture of heat control material A and heat control material B in a mass ratio of 4:1.

[0019] The preparation method of the heat control material A comprises the following steps: melting n-octadecane and expanded graphite together to obtain core material A, then adding an emulsifier, stirring, dispersing, and forming a Pickering emulsion; melting docosane and adding boron nitride to form a core material B solution; dropping the Pickering emulsion into the core material B solution, stirring and mixing to form a composite emulsion; then sequentially adding the inner wall material solution SiO2 sol and the outer wall material solution polymethyl methacrylate pre-polymer to the composite emulsion, and simultaneously dispersing, controlling the pH value of the reaction system to be 2.5-3.0, and the temperature to be 55-65℃, and completing the SiO2 / polymethyl methacrylate double-layer coating; centrifuging, drying, and obtaining the heat control material A.

[0020] The preparation method of the thermal control material B comprises the following steps: dispersing amino-functionalized carbon nanotubes and Al2O3 nanosheets in an alkaline ethanol aqueous solution to form a uniform suspension; then adding γ-aminopropyl triethoxysilane, heating, stirring, adding silver-loaded zirconium phosphate particles, and stirring; standing, defoaming, vacuum filtration to form a film, and adopting a gradient pressure and temperature heating pressing process to realize densification and structure shaping of the film layer.

[0021] In some embodiments of the present application, in the preparation method of the thermal control material A, n-octadecane: expanded graphite = 7-12:1 (w / w), docosane: boron nitride = 6-10:2 (w / w), core material A: core material B solution = 0.85-0.95:1 (w / w), SiO2 sol: polymethyl methacrylate prepolymer = 0.8-1.2:1 (v / v), and composite emulsion: SiO2 sol = 1:0.5-0.7 (w / w), preferably 1:0.6 (w / w);

[0022] Preferably, the emulsifier is a mixture of Span and polyglycerol castor oil ester, and the mass ratio is 1:8-12, preferably 1:10; the amount of the emulsifier is 4-7 wt% of the total weight of the core material A and the core material B solution, preferably 5.5 wt%;

[0023] Preferably, the particle size of the SiO2 sol is less than 15 nm.

[0024] Preferably, the average molecular weight of the polymethyl methacrylate (PMMA) prepolymer is 15,000 Dalton, and the composition comprises 95 wt% of methyl methacrylate monomer, 5 wt% of crosslinking agent, and 0.05 wt% of initiator based on the total mass of the monomer. More preferably, the crosslinking agent is ethylene glycol dimethacrylate, and the initiator is azobisisobutyronitrile.

[0025] Preferably, supercritical CO2 drying is adopted to obtain the thermal control material A

[0026] In some embodiments of the present application, in the preparation method of the thermal control material B, the mass ratio of amino-functionalized carbon nanotubes: Al2O3 nanosheets: silver-loaded zirconium phosphate particles: γ-aminopropyl triethoxysilane is 4.5-5.5:4:1.5:0.6 (mass ratio); the mass ratio of the amino-functionalized carbon nanotubes to the alkaline ethanol aqueous solution is 1:5-8, preferably 1:7.

[0027] The aspect ratio of the amino-functionalized carbon nanotubes is greater than 800.

[0028] The thickness of the Al2O3 nanosheets is less than 30 nm.

[0029] The particle size of the silver-loaded zirconium phosphate particles is less than 20 nm, and the Ag loading amount is 5-7 wt%, preferably 6 wt%.

[0030] The pH value of the alkaline ethanol aqueous solution is 8-9, preferably 8.5; wherein the volume ratio of ethanol to water is 0.8-1.2:1, preferably 1:1;

[0031] The wet film formed by suction filtration is pre-pressed at 4-6 MPa and 45-55 DEG C for 5-20 min, and then is finally pressed at 6-10 MPa and 58-70 DEG C for 10-30 min to obtain the thermal control material B.

[0032] The present application discloses a preparation method of a cement slurry system for deep water hydrate layer cementing, comprising the following steps: weighing each material according to steps, mixing to obtain dry mixture, and preparing cement slurry by adding water.

[0033] Preferably, the water-cement ratio of the cement slurry is 0.55.

[0034] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0035] The present application provides a cement slurry system for deep water hydrate layer cementing. The system has low hydration heat, low temperature early strength, adjustable density, excellent rheological properties, low filtration loss, short waiting-on-cement time and other advantages, and the material sources are widely available, which has significant cost benefits and is convenient for field cementing operation.

[0036] The present application creatively introduces a heat-conducting enhanced phase change temperature control material, which forms a two-stage phase change and heat-conducting synergistic control system through unique component design and preparation process: the thermal control material A is used as a thermal energy storage / release unit, adopts a double-core material structure design, widens the temperature response range of the material, effectively alleviates the temperature fluctuation generated in the cement hydration process through efficient thermal energy storage and release, thereby significantly reducing the hydration heat of the system. The thermal control material B constructs a continuous three-dimensional heat-conducting network skeleton in the system, which can quickly and uniformly disperse local heat, prevent heat concentration, and avoid the decomposition of hydrate layer induced by local temperature rise. Under the synergistic action of the two, the system has a lower hydration heat.

[0037] The heat-conducting enhanced phase change temperature control material has low density, which can reduce the density of the cement slurry system, reduce the dependence on traditional lightening materials, and further reduce the cost. The present application has high strength and good compatibility through double-layer coating and other treatment methods, has little effect on the rheological properties and strength of the cement slurry system, and is beneficial to improving the toughness of the cement stone.

[0038] In summary, the cement slurry system of the present application is particularly suitable for deep water hydrate formation cementing operation. By effectively controlling the hydration heat and temperature distribution, the key technical problems in deep water hydrate layer cementing are successfully solved, which can maximize the prevention of hydrate decomposition during cementing, and ensure the integrity of the wellbore and the safety of the construction. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be described clearly and completely below in combination with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0040] The heat-conducting enhanced phase change temperature control material in the embodiments of the present application is obtained by mixing heat control material A and heat control material B at a mass ratio of 4:1. The specific steps are as follows: heat control material A and heat control material B are put into a three-dimensional mixer, a 20℃ water cooling jacket is set, and after mixing at 30rpm for 30min, the speed is increased to 45rpm and mixed for another 10min, and then the material is discharged, thereby obtaining the heat-conducting enhanced phase change temperature control material.

[0041] The preparation method of the heat control material A includes the following steps:

[0042] S1. n-Octadecane and expanded graphite with a mass ratio of 9:1 are added to a temperature control reaction kettle, heated to 32±0.5℃, and stirred at 300rpm for 20min until completely melted to form core material A; a composite emulsifier is added to the core material A, pre-dispersed at 3000rpm for 5min, and then finely emulsified at 5000rpm for 10min to form a Pickering emulsion;

[0043] S2. After melting at 50℃, boron nitride is added to the core material B solution, and ultrasonic dispersion is performed for 30min to form a core material B solution, and the mass ratio of the melted eicosane to boron nitride is 8:2;

[0044] S3. The Pickering emulsion is dropped into the core material B solution at a rate of 5ml / min through a constant temperature delivery pump, and mixed at 200rpm for 15min to form a composite emulsion; wherein the mass ratio of the core material A to the core material B solution is 0.85:1;

[0045] S4. The inner wall material solution SiO2 sol is added to the composite emulsion at a rate of 1ml / min, and after the addition is completed, the outer wall material solution polymethyl methacrylate prepolymer is added, and stirring is performed at 300rpm and ultrasonic dispersion is performed synchronously during the addition process, the pH value of the reaction system is controlled to be 2.5-3.0, and the reaction temperature is controlled to be 55-65℃, and the SiO2 / polymethyl methacrylate double-layer coating is completed; centrifugation is performed, supercritical CO2 drying is adopted, and the heat control material A is obtained;

[0046] The particle size of the expanded graphite is <50μm; the composite emulsifier is obtained by mixing Span 80 and polyglyceryl castor oil with a mass ratio of 1:10; the amount of the composite emulsifier is 5.5wt% of the total weight of the core material A and the core material B solution, and the mass ratio of the composite emulsion to the SiO2 sol is 1:0.6.

[0047] SiO2 sol: polymethyl methacrylate prepolymer = 1:1 (v / v); SiO2 sol particle size < 15 nm;

[0048] The average molecular weight of the polymethyl methacrylate (PMMA) prepolymer is 15,000 Dalton, and the composition is: 95wt% methyl methacrylate monomer, 5wt% ethylene glycol dimethacrylate, and 0.05wt% of the total mass of the monomers azobisisobutyronitrile.

[0049] The preparation method of the thermal control material B comprises the following steps:

[0050] Step (1): disperse the aminated carbon nanotube in the ethanol aqueous solution (ethanol: water = 1:1, volume ratio) with pH = 8.5, ultrasonic dispersion for 30 min, then add 30% Al2O3 nanosheet, 500 rpm magnetic stirring for 30 min, then add the remaining 70% Al2O3 nanosheet, 500 rpm magnetic stirring for 30 min, to form a uniform suspension;

[0051] Step (2): add γ-aminopropyl triethoxysilane to the suspension prepared in step (1), 60℃ magnetic stirring for 40 min, then add 50% silver-loaded zirconium phosphate particles, magnetic stirring for 2h, then add the remaining 50% silver-loaded zirconium phosphate particles, magnetic stirring for 2h;

[0052] Step (3): the material obtained in step (2) is left to stand for 30 min to remove bubbles, then vacuum filtration to form a film, first 5MPa / 50℃ pre-pressing for 10 min, then 8MPa / 60℃ final pressing for 15 min, to obtain the thermal control material B.

[0053] The mass ratio of the aminated carbon nanotube, Al2O3 nanosheet, silver-loaded zirconium phosphate particles and γ-aminopropyl triethoxysilane is 4.5:4:1.5:0.6; the mass ratio of the aminated carbon nanotube and the basic ethanol aqueous solution is 1:7;

[0054] The aspect ratio of the aminated carbon nanotube is >800; the thickness of the Al2O3 nanosheet is <30nm; the particle size of the silver-loaded zirconium phosphate particles is <20nm, and the Ag loading amount is 6wt%.

[0055] Example 1

[0056] This example discloses the cement slurry system for deep water hydrate layer cementing of the present application, which comprises:

[0057] G-class oil well cement 59wt.%, microsilica 2wt.%, low water heat cementing material 15wt.%, density reducing material 5wt.%, suspension stabilizing material 3wt.%, thermal conductivity enhancing phase change temperature control material 10wt.%, early strength agent 3wt.%, dispersant 1wt.%, fluid loss additive 2wt.%.

[0058] The microsilica powder has a particle size less than 10 μm.

[0059] The low water heat cementing material is a mixture of metakaolin and lithium slag in a mass ratio of 3:2, and both have a particle size less than 45 μm.

[0060] The density reducing material is fly ash hollow microsphere with a particle size less than 20 μm and a density of 0.72 g / cm 3 .

[0061] The suspension stabilizing material is a mixture of superfine dolomite powder and superfine aluminum silicate in a mass ratio of 15:1, and both have a particle size less than 5 μm.

[0062] The early strength agent is a mixture of triisopropanolamine, sodium salt of nitrilotriacetic acid and sodium sulfate in a mass ratio of 1:2:4.

[0063] The dispersant is polycarboxylic acid.

[0064] The fluid loss additive is 2-acrylamide-2-methylpropanesulfonic acid (AMPS) polymer.

[0065] The preparation method of the cement slurry system for deep water hydrate layer cementing in the embodiment is as follows:

[0066] The materials are weighed according to the above proportions, mixed uniformly to obtain dry mixture, and then a cement slurry is prepared according to GB / T-19139 standard, with a water-cement ratio of 0.55, to obtain the cement slurry 1# for deep water hydrate layer cementing.

[0067] Example 2

[0068] The embodiment discloses a cement slurry system for deep water hydrate layer cementing according to the application, which comprises the following components:

[0069] G-class oil well cement 59wt.%, microsilica 2wt.%, low water heat cementing material 15wt.%, density reducing material 5wt.%, suspension stabilizing material 3wt.%, thermal conductivity enhancing phase change temperature control material 10wt.%, early strength agent 3wt.%, dispersant 1wt.%, fluid loss additive 2wt.%.

[0070] The microsilica powder has a particle size less than 10 μm.

[0071] The low water heat cementing material is a mixture of metakaolin and lithium slag in a mass ratio of 3:2, and both have a particle size less than 45 μm.

[0072] The density-reducing material is fly ash hollow microbeads with a particle size of less than 20 μm and a density of 0.72 g / cm 3 ;

[0073] The suspension stabilizing material is a mixture of superfine dolomite powder and superfine aluminum silicate in a mass ratio of 15:1, and the particle size of both is less than 5 μm;

[0074] The early strength agent is a mixture of triisopropanolamine, sodium salt of nitrilotriacetic acid and sodium sulfate in a mass ratio of 1:2:4;

[0075] The dispersant is a polycarboxylic acid;

[0076] The fluid loss additive is a 2-acrylamide-2-methylpropanesulfonic acid (AMPS) polymer;

[0077] The preparation method of the cement slurry system for deepwater hydrate layer cementing in the embodiment is as follows:

[0078] The materials are weighed according to the above proportions, mixed uniformly to obtain dry mix, and a cement slurry is prepared according to GB / T-19139 standard, with a water-cement ratio of 0.55, to obtain the cement slurry 2# for deepwater hydrate layer cementing.

[0079] Embodiment 3

[0080] The embodiment discloses a cement slurry system for deepwater hydrate layer cementing of the application, which comprises the following components:

[0081] G-grade oil well cement 77 wt.%, microsilica 2 wt.%, low hydration heat cementing material 10 wt.%, density-reducing material 3 wt.%, suspension stabilizing material 1 wt.%, heat-conducting enhanced phase change temperature control material 5 wt.%, early strength agent 1 wt.%, dispersant 0.5 wt.% and fluid loss additive 0.5 wt.%.

[0082] The microsilica powder has a particle size of less than 10 μm;

[0083] The low hydration heat cementing material is a mixture of metakaolin and lithium slag in a mass ratio of 3:2, and the particle size of both is less than 45 μm;

[0084] The density-reducing material is fly ash hollow microbeads with a particle size of less than 20 μm and a density of 0.72 g / cm 3 ;

[0085] The suspension stabilizing material is a mixture of superfine dolomite powder and superfine aluminum silicate in a mass ratio of 15:1, and the particle size of both is less than 5 μm;

[0086] The early strength agent is a mixture of triisopropanolamine, sodium salt of nitrilotriacetic acid and sodium sulfate in a mass ratio of 1:2:4;

[0087] The dispersant is a polycarboxylic acid;

[0088] The fluid loss additive is a 2-acrylamide-2-methylpropanesulfonic acid (AMPS) polymer;

[0089] The preparation method of the cement slurry system for deepwater hydrate layer cementing in the embodiment is as follows:

[0090] The materials are weighed according to the above proportions, uniformly mixed to obtain dry mix, and a cement slurry is prepared according to GB / T-19139 standard, with a water-cement ratio of 0.55, to obtain the cement slurry 3# for deepwater hydrate layer cementing.

[0091] Comparative Example 1

[0092] This comparative example does not contain low hydration heat cementing material compared with Example 1, and the other conditions are the same.

[0093] Comparative Example 2

[0094] This comparative example does not contain a suspension stabilizing material compared with Example 1, and the other conditions are the same.

[0095] Comparative Example 3

[0096] This comparative example does not contain a heat-conducting enhanced phase change temperature control material compared with Example 1, and the other conditions are the same.

[0097] Test Example

[0098] The density, fluid loss, fluidity, compressive strength and elastic modulus of the cement slurry systems prepared in Examples 1-3 and Comparative Examples 1-3 are tested according to GB / T19139 Oil Well Cement Test Method, and the results are shown in Table 1. In addition, the hydration heat release performance of the above cement slurries is tested, and the results are shown in Table 2.

[0099] Table 1: Basic performance test results of cement slurry

[0100]

[0101]

[0102] The test results in Table 1 show that for the needs of deepwater hydrate layer cementing, the cement slurry system of the present application exhibits key advantages: low and adjustable density, low fluid loss, excellent rheological property, ensuring smooth construction; its high compressive strength, low elastic modulus and good toughness resulting therefrom significantly improve the long-term integrity of the cementing body.

[0103] Table 2: Hydration heat release performance test results

[0104]

[0105] As can be seen from the data in Table 2, the cement slurry system designed for cementing in deep-water hydrate layer has the characteristics of low hydration temperature rise and hydration heat release, effectively solves the technical problems of cementing in deep-water hydrate layer, and can prevent hydrates from decomposing due to heat. Through the analysis of Comparative Examples 1-3, it can be known that the heat-conducting phase-change temperature control material added in the present application plays an important role in significantly reducing the hydration heat release of the cement slurry system. At the same time, the low hydration heat gelling material and the suspension stabilizing material also have similar effects to a certain extent. The synergistic effect of the three makes the cement slurry system of the present application have a significant advantage in reducing the hydration temperature rise and heat release.

[0106] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification or equivalent change made on the basis of the technical essence of the present application to the above embodiment falls within the protection scope of the present application.

Claims

1. A cement slurry system for deep water hydrate zone cementing, characterized in that, The components include the following weight parts: G-grade oil well cement: 59-77 wt. %, Microsilica: 2 wt. %; Low water heat cementing material: 10-15 wt. %; Density reducing material: 3-5 wt. %; Suspension stabilizing material: 1-3 wt. %; Thermal conductivity enhancing phase change temperature control material: 5-10 wt. %; Early strength agent: 1-3 wt. %; Dispersant: 0.5-1 wt. %; Fluid loss additive: 0.5-2 wt. %.

2. The cement slurry system for deepwater hydrate zone cementing according to claim 1, characterized in that, The low water heat cementing material is a mixture of metakaolin and lithium slag in a mass ratio of 3:1-3; preferably 3:2; Preferably, the particle size of both metakaolin and lithium slag is less than 45 μm.

3. The cement slurry system for deepwater hydrate zone cementing according to claim 1, characterized in that, The density-reducing material is fly ash hollow microsphere, with a particle size of less than 20 μm and a density of 0.65-0.80 g / cm 3 , preferably 0.72 g / cm 3 .

4. The cement slurry system for deep water hydrate zone cementing of claim 1, wherein, The suspension stabilizing material is a mixture of superfine dolomite powder and superfine aluminum silicate in a mass ratio of 10-20:1, preferably 15:1; Preferably, the particle size of both superfine dolomite and superfine aluminum silicate is less than 5 μm.

5. The cement slurry system for deep water hydrate zone cementing according to claim 1, characterized in that, The early strength agent is a mixture of triisopropanolamine, sodium salt of nitrilotriacetic acid and sodium sulfate in a mass ratio of 1:2:4; The dispersant is a polycarboxylic acid; The fluid loss additive is a 2-acrylamide-2-methylpropanesulfonic acid (AMPS) polymer.

6. The deepwater hydrate-bearing interval cementing slurry system according to any one of claims 1-5, characterized in that, The thermal conductivity enhancing phase change temperature control material is a mixture of heat control material A and heat control material B in a mass ratio of 3-5:1; The preparation method of the heat control material A includes the following steps: melting n-octadecane and expanded graphite together to obtain core material A, then adding an emulsifier, stirring, dispersing, and forming a Pickering emulsion; melting docosane and adding boron nitride to form a core material B solution; dropping the Pickering emulsion into the core material B solution, stirring and mixing, forming a composite emulsion; then sequentially adding SiO2 sol and polymethyl methacrylate pre-polymer solutions as inner and outer wall materials to the composite emulsion, and synchronously dispersing, controlling the pH value of the reaction system to be 2.5-3.0 and the temperature to be 55-65℃, and completing the SiO2 / polymethyl methacrylate double-layer coating; centrifuging, drying, and obtaining the heat control material A; The preparation method of the heat control material B includes the following steps: dispersing amino-functionalized carbon nanotubes and Al2O3 nanosheets in an alkaline ethanol aqueous solution to form a uniform suspension; then adding γ-aminopropyltriethoxysilane, heating, stirring, adding silver-loaded zirconium phosphate particles, and stirring; standing, defoaming, vacuum filtration to form a film, and using a gradient pressure and temperature increasing hot pressing process to realize film densification and structure setting.

7. The cement slurry system for deepwater hydrate zone cementing of claim 6, wherein, In the preparation method of the heat control material A, n-octadecane: expanded graphite = 7-12:1 (w / w), docosane: boron nitride = 6-10:2 (w / w), core material A: core material B solution = 0.85-0.95:1 (w / w), and SiO2 sol: polymethyl methacrylate pre-polymer = 0.8-1.2:1 (v / v); Preferably, the emulsifier is a mixture of Span and polyglycerol castor oil ester; the mass ratio is 1:8-12; preferably 1:10; the amount of the emulsifier is 4-7 wt% of the total weight of the core material A and the core material B solution, preferably 5.5 wt%. Preferably, the average molecular weight of the polymethyl methacrylate (PMMA) prepolymer is 15,000 Dalton, and the composition thereof is: 95wt% of methyl methacrylate monomer, 5wt% of crosslinking agent, and 0.05wt% of initiator accounting for the total mass of monomers; more preferably, the crosslinking agent is ethylene glycol dimethacrylate, and the initiator is azobisisobutyronitrile. Preferably, the heat control material A is obtained by using supercritical CO2 drying.

8. The cement slurry system for deep water hydrate zone cementing of claim 6, wherein, In the preparation method of the heat control material B, the amino-functionalized carbon nanotube: Al2O3 nanosheet: silver-loaded zirconium phosphate particle: γ-aminopropyl triethoxysilane = 4.5-5.5:4:1.5:0.6 (mass ratio); The aspect ratio of the amino-functionalized carbon nanotube is >800; The thickness of the Al2O3 nanosheet is <30nm; The particle size of the silver-loaded zirconium phosphate particle is <20nm, and the Ag loading is 5-7wt%, preferably 6wt%. The pH value of the alkaline ethanol aqueous solution is 8-9, preferably 8.5; and the volume ratio of ethanol to water is 0.8-1.2:1, preferably 1:1; The wet film formed by suction filtration is pre-pressed at 4-6MPa and 45-55℃ for 5-20min, and then finally pressed at 6-10MPa and 58-70℃ for 10-30min to obtain the heat control material B.

9. The method for preparing the cement slurry system for deepwater hydrate layer cementing according to any one of claims 1-8, characterized in that, The method comprises the following steps: weighing each material according to the steps, mixing to obtain dry mixture, and adding water to prepare cement slurry.

10. The method of preparing a cement slurry system for deep water hydrate zone cementing according to claim 9, characterized in that, The water-cement ratio of the cement slurry is 0.55.

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