Elastic and tough foam cement paste and preparation method thereof

Abstract

The invention relates to the technical field of foam well cementation of petroleum and natural gas wells, in particular to elastic and tough foam cement paste and a preparation method of the elastic and tough foam cement paste. The concrete comprises 100 parts of cement, 5-20 parts of a lightening material, 10-20 parts of an elastic material, 5-15 parts of silicon powder, 5-15 parts of a fluid loss agent, 2-8 parts of a retarder, 1-5 parts of a dispersing agent, 5-10 parts of a foaming agent, 1-5 parts of a foam stabilizer and 50-70 parts of water, wherein the cement is oil well G-grade cement; in the latter, a solid-phase material and prepared slurry are prepared firstly, then the solid-phase material is added into the prepared slurry, and the elastic and tough foam cement slurry is obtained through uniform stirring and mixing. According to the elastic and tough foam cement paste and the preparation method thereof, the raw materials of the cement paste are simple and easy to obtain, preparation is simple, the field technical requirements can be met, and particularly, the well cementation quality can be effectively improved in well cementation construction of gas storages and low-pressure leakage-prone complex wells.

Description

Technical Field

[0001] This invention relates to the field of foam cementing technology for oil and gas wells, specifically a resilient foam cement slurry and its preparation method. Background Technology

[0002] Currently, due to long-term mining operations in production wells, the formation pressure system is disrupted, and low-pressure, easily leaking formations are common during drilling. Therefore, a large amount of low-density cement slurry is needed for cementing operations. Conventional cenosphere-based low-density cement slurry produces cement stone with insufficient mechanical properties, manifested in low compressive strength and excessive Young's modulus. With the implementation of oil and gas well production enhancement and efficiency targets, large-scale volumetric fracturing has become the main method of development well production. Low-density cement stone with insufficient mechanical properties, lacking elasticity and toughness, is prone to fracture under high-pressure impact, ultimately affecting oil and gas recovery rates and well lifespan.

[0003] Compared to conventional low-density cement slurry with cenospheres, foamed cement slurry has a good density advantage and anti-channeling performance, which can achieve efficient sealing of low-pressure and easily leaking formations. Although it has a wide range of application prospects, the slurry material contains few components that can improve mechanical properties, which means it is also unable to resist the permanent damage to the cement stone caused by high pressure during fracturing operations.

[0004] Based on the above problems, it is necessary to research and invent an elastic and resilient foamed cement slurry and its preparation method to solve the problems of low compressive strength, excessive Young's modulus, insufficient mechanical properties of cement stone, lack of elasticity and toughness in traditional cement slurry systems, and easy rupture and micro-annulus formation when subjected to high pressure impact. This would meet the cementing requirements of perforation, large volume fracturing, and horizontal well cementing as the main extraction methods, and improve oil and gas recovery rate and oil and gas well life. Summary of the Invention

[0005] This invention provides an elastic and resilient foamed cement slurry and its preparation method, which overcomes the shortcomings of the prior art and can effectively solve the problem that the existing cement slurry system has insufficient mechanical properties of cement stone, which affects the improvement of oil and gas recovery rate and the production life of oil and gas wells.

[0006] One of the technical solutions of the present invention is achieved through the following measures: an elastic and resilient foamed cement slurry, wherein the raw materials are in the following proportions by weight: 100 parts cement, 5 to 20 parts lightweighting material, 10 to 20 parts elastic material, 5 to 15 parts silica fume, 5 to 15 parts water loss reducing agent, 2 to 8 parts retarder, 1 to 5 parts dispersant, 5 to 10 parts foaming agent, 1 to 5 parts foam stabilizer, and 50 to 70 parts water.

[0007] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: The above-mentioned cement is one of medium sulfur-resistant cement and high sulfur-resistant cement; and / or the weight-reducing material is one or more of cenospheres, hollow glass microspheres, expanded perlite, and fly ash; The aforementioned elastic material is one or more of latex particles, polyacrylonitrile fibers, and viscose fibers; The aforementioned silica powder is one of 300 mesh, 500 mesh, and 1000 mesh quartz sand; The aforementioned water loss reducing agent is one of the following: a copolymer of sulfonated polystyrene, sulfonated polymethylstyrene, itaconic acid, and N-methyl-N-ethylacetamide, and a copolymer of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and acrylamide; The aforementioned retarder is one of a copolymer of 2-acrylamide-2-methylpropanesulfonic acid, itaconic acid, and acrylamide with a copolymer of 2-acrylamide-2-methylpropanesulfonic acid, maleic acid, acrylic acid, and dimethyldiallylammonium chloride; or / and, the dispersant is one of a copolymer of naphthalene sulfonate, a condensation polymer of naphthalene sulfonate with sodium aminobenzenesulfonate, phenol, and formaldehyde; or / and, the foaming agent is one of alkylphenol polyoxyethylene ether and sodium dodecylbenzenesulfonate; or / and, the foam stabilizer is one or more of octyldecyl glycoside, lauramide propyl ammonium oxide, cocamidopropyl hydroxysulfobetaine, and sodium dodecyl sulfate; or / and, the water is fresh water or brine with a concentration of 0 to 18%.

[0008] The above-mentioned elastic and resilient foamed cement slurry was prepared according to the following method: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

[0009] In the second step above, the stirring speed is 1000 r / min to 1200 r / min. After adding the water loss reducer, retarder, and dispersant in sequence, the stirring times are 15 s, 15 s, and 20 s, respectively. After adding the foaming agent and foam stabilizer, the stirring speed is adjusted to 2500 r / min and stirred for 35 s.

[0010] In the third step above, adjust the stirring speed to 3800 r / min to 4200 r / min, add the solid material to the slurry within 30 to 35 seconds, and continue stirring for 30 to 40 seconds after adding.

[0011] The second technical solution of the present invention is achieved through the following measures: a method for preparing elastic and resilient foamed cement slurry, which is carried out according to the following method: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

[0012] This invention improves compressive strength and Young's modulus by adding silica powder and elastic materials to the solid phase to effectively fill cement pores. At the same time, adding foaming agents and foam stabilizers to the liquid phase allows the generated foam to quickly reduce the density of the cement slurry. This prevents the cement sheath from developing microcracks and micro-annular gaps due to perforation, fracturing, and other processes after the elastic and tough foamed cement slurry has solidified. This ensures the integrity of the cement sheath, increases oil and gas production, and extends the life of oil and gas extraction. Detailed Implementation

[0013] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solution of this invention and actual conditions. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art; unless otherwise specified, all percentages in this invention are mass percentages.

[0014] The present invention will be further described below with reference to embodiments: Example 1: The elastic and tough foamed cement slurry contains the following raw materials by weight: 100 parts cement, 5 to 20 parts lightweighting material, 10 to 20 parts elastic material, 5 to 15 parts silica fume, 5 to 15 parts water loss reducing agent, 2 to 8 parts retarder, 1 to 5 parts dispersant, 5 to 10 parts foaming agent, 1 to 5 parts foam stabilizer, and 50 to 70 parts water.

[0015] In this invention, the cement is oil well grade G cement, the fluid loss reducing agent is a liquid fluid loss reducing agent, the retarder is a liquid retarder, the dispersant is a solid dispersant, the foaming agent is a liquid foaming agent, and the foam stabilizer is a liquid foam stabilizer.

[0016] Example 2: As an optimization of the above example, the cement is one of medium sulfur-resistant cement and high sulfur-resistant cement. Example 3: As an optimization of the above embodiments, the weight-reducing material is one or more of the following: cenospheres, hollow glass microspheres, expanded perlite, and fly ash. Example 4: As an optimization of the above embodiments, the elastic material is one or more of latex particles, polyacrylonitrile fibers, and viscose fibers. Example 5: As an optimization of the above examples, the silica powder is one of 300 mesh, 500 mesh, and 1000 mesh quartz sand. Example 6: As an optimization of the above examples, the water loss reducing agent is one of the following: a copolymer of sulfonated polystyrene, sulfonated polymethylstyrene, itaconic acid, and N-methyl-N-ethylacetamide, and a copolymer of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and acrylamide. Example 7: As an optimization of the above examples, the retarder is one of the copolymers of 2-acrylamide-2-methylpropanesulfonic acid, itaconic acid, and acrylamide, and a copolymer of 2-acrylamide-2-methylpropanesulfonic acid, maleic acid, acrylic acid, and dimethyldiallyl ammonium chloride. Example 8: As an optimization of the above examples, the dispersant is one of naphthalene sulfonate, a condensation polymer of naphthalene sulfonate, sodium aminobenzenesulfonate, phenol, and formaldehyde copolymer. Example 9: As an optimization of the above examples, the foaming agent is one of alkylphenol polyoxyethylene ether and sodium dodecylbenzene sulfonate. Example 10: As an optimization of the above examples, the foam stabilizer is one or more of octyldecyl glycoside, lauramide propyl ammonium oxide, cocamidopropyl hydroxysulfonate betaine, and sodium dodecyl sulfate. Example 11: As an optimization of the above example, the water is fresh water or salt water (NaCl solution) with a concentration of 0 to 18%.

[0017] In this invention, silica powder, an anti-high temperature strength degradation agent that can effectively fill cement pores, and elastic materials are added to the solid phase to improve compressive strength and Young's modulus. At the same time, foaming agents and foam stabilizers are added to the liquid phase to rapidly reduce the density of cement slurry using the generated foam. Ultimately, this prevents the cement sheath from developing microcracks and micro-annular gaps due to perforation, fracturing, and other operations after the elastic and tough foam cement slurry has solidified, thus ensuring the integrity of the cement sheath, increasing oil and gas production, and extending the life of oil and gas extraction.

[0018] The elastic and tough foamed cement slurry of the present invention has an adjustable density in the range of 1.00 g / cm³ to 1.60 g / cm³, good stability, adjustable thickening time, 48h compressive strength ≥14 MPa, and 7d Young's modulus ≤5 GPa, which can meet the requirements of long-term integrity of low-density foamed cement sheath in large-volume fracturing and horizontal well cementing environments.

[0019] After adding weight-reducing and elastic materials, the solid phase component in the resulting elastic-tough foamed cement slurry is significantly increased compared to the conventional cement slurry system. However, the density difference between the upper, middle, and lower parts of the slurry can be controlled within ±0.03 g / cm³, avoiding the risk of slurry settling, pump blockage, and construction interruption. The addition of elastic materials significantly reduces the Young's modulus of the elastic-tough foamed cement slurry, which can effectively resist damage to the cement sheath under high pressure in large-volume fracturing modification construction, thereby ensuring the integrity of the cement sheath. It is easy to mix, with reasonable particle size distribution of elastic materials, weight-reducing materials, and silica fume, and simple on-site preparation.

[0020] Example 12: As an optimization of the above examples, this elastic and resilient foamed cement slurry was prepared according to the following method: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

[0021] If necessary, a mixer can be used for mixing as described above; the mixer can be a corrugated mixer.

[0022] The elastic and tough foamed cement slurry of the present invention incorporates the required amount of elastic material and silica powder. Through the formation of an effective particle size distribution between the solid phase material of different particle sizes and cement, the compressive strength of low-density cement stone is improved. At the same time, due to the film-forming properties of the elastic material, the generation and development of microcracks inside the cement stone are restricted, thereby improving the impact toughness.

[0023] By adding foaming agents and foam stabilizers, the cement slurry is filled with uniform and dense air bubbles. Stable air bubbles can significantly reduce the density of the cement slurry, resulting in a foamed cement slurry that can be applied on-site. The elastic and resilient foamed cement slurry can solve the technical problem of cementing stability and leakage prevention in low-pressure and easily leaking formations, while also meeting the technical requirements of cement stone for subsequent fracturing and stimulation, thus achieving dual optimization of recovery rate and production life.

[0024] Example 13: As an optimization of the above example, in the second step, the stirring speed is 1000 r / min to 1200 r / min. After adding the water loss reducer, retarder, and dispersant in sequence, the stirring times are 15 s, 15 s, and 20 s, respectively. After adding the foaming agent and foam stabilizer, the stirring speed is adjusted to 2500 r / min and stirred for 35 s.

[0025] Example 14: As an optimization of the above example, in the third step, the stirring speed is adjusted to 3800 r / min to 4200 r / min, and the solid material is added to the slurry within 30 to 35 seconds. After adding, stirring is continued for 30 to 40 seconds.

[0026] Example 15: The preparation method of this elastic and tough foamed cement slurry is as follows: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

[0027] The preparation method provided by this invention does not have special requirements for the preparation environment in the laboratory or on site. In on-site construction, cement trucks can be used for self-mixing and self-injection, or the mixture can be prepared in fixed tanks and quantitatively and then pumped in by pump trucks. The operation is flexible and convenient.

[0028] All raw materials used in the following embodiments of the present invention are commercially available products. The cement used is oil well grade G HSR high sulfur-resistant cement; the weight-reducing material is hollow glass microspheres with a compressive strength of 82 MPa, provided by Sinosteel Group Maanshan Mining Research Institute New Material Technology Co., Ltd.; the elastic material has a density of 1.70 g / cm³. 3 The latex powder was provided by CNPC Engineering Technology Research Institute Co., Ltd.; the silica powder, with a particle size of 300 mesh and a SiO2 content of ≥95%, was provided by Chengdu Hongyunyang Technology Co., Ltd.; the water loss reducing agent was RK-13L, a sulfonated polystyrene copolymer water loss reducing agent provided by Shandong Jinyuan New Material Technology Co., Ltd.; the dispersant was MF, a polynaphthalene sulfonate dispersant provided by Hubei Xingyan New Material Technology Co., Ltd.; the retarder was HS-R, a 2-acrylamide-2-methylpropanesulfonic acid polymer retarder provided by Chengdu Chuanfeng Chemical Engineering Co., Ltd.; the foaming agent was KSF-II, a sodium dodecylbenzene sulfonate foaming agent provided by the First Branch of Huakuang Heavy Industry Co., Ltd.; and the foam stabilizer was CAO-30, a mixture of cocamidopropyl hydroxysulfonate betaine and sodium dodecyl sulfate, provided by Shandong Tonglan Chemical Co., Ltd.

[0029] Example 16: This elastic and resilient foamed cement slurry was prepared according to the following method: The first step is to add 300g of oil well grade G HSR high sulfur-resistant cement, 60g of light-reducing material, 54g of elastic material, and 45g of silica fume into a corrugated slurry cup, and mix them evenly with a corrugated mixer to obtain a solid phase material. The second step involves using a corrugated mixer at a speed of 1200 r / min. First, add 27 g of water loss reducer to 210 g of water and stir for 15 seconds. Then, add 6 g of retarder and stir for 15 seconds. Next, add 12 g of dispersant and stir for 20 seconds. Finally, add 24 g of foaming agent and 9 g of foam stabilizer. Adjust the stirring speed to 2500 r / min and stir for 35 seconds to obtain the slurry.

[0030] The third step involves adjusting the corrugated mixer speed to 4200 r / min, adding the solid material to the slurry within 35 seconds, and continuing to stir for another 35 seconds to obtain a density of 1.35 g / cm³. 3 Elastic and resilient foamed cement slurry.

[0031] Example 17: Weigh 500g of oil well G-grade HSR high sulfur-resistant cement, 80g of weight-reducing material, 75g of elastic material, 60g of silica fume, 30g of fluid loss reducing agent, 10g of dispersant, 10g of retarder, 35g of foaming agent, 10g of foam stabilizer, and 335g of water. Following the preparation method in Example 8, a density of 1.50g / cm³ was obtained. 3 Elastic and resilient foamed cement slurry.

[0032] Example 18: Weigh 600g of oil well grade G HSR high sulfur-resistant cement, 78g of weight-reducing material, 60g of elastic material, 54g of silica fume, 24g of fluid loss reducing agent, 6g of dispersant, 12g of retarder, 36g of foaming agent, 6g of foam stabilizer, and 372g of water. Following the preparation method in Example 8, a density of 1.60g / cm³ was obtained. 3 Elastic and resilient foamed cement slurry.

[0033] Comparative Example 1: 300g of oil well grade G HSR high sulfur-resistant cement, 60g of weight-reducing material, 27g of fluid loss control agent, 12g of dispersant, 6g of retarder, 24g of foaming agent, 9g of foam stabilizer, and 195g of water were weighed and prepared according to the preparation method of Example 8 to obtain a density of 1.35g / cm³. 3 Conventional foamed cement slurry.

[0034] Comparative Example 2: 500g of oil well grade G HSR high sulfur-resistant cement, 80g of weight-reducing material, 30g of fluid loss control agent, 10g of dispersant, 10g of retarder, 35g of foaming agent, 10g of foam stabilizer, and 305g of water were weighed and prepared according to the method in Example 8 to obtain a density of 1.50g / cm³. 3 Conventional foamed cement slurry.

[0035] Comparative Example 3: 600g of oil well grade G HSR high sulfur-resistant cement, 78g of weight-reducing material, 24g of fluid loss control agent, 6g of dispersant, 12g of retarder, 36g of foaming agent, 6g of foam stabilizer, and 330g of water were weighed and prepared according to the method in Example 8 to obtain a density of 1.60g / cm³. 3 Conventional foamed cement slurry.

[0036] According to GB / T19139-2012 Oil Well Cement Test Methods, comparative experiments were conducted on the elastic and tough foamed cement slurries obtained in Examples 16 to 18 and the conventional foamed cement slurries obtained in Comparative Examples 1 to 3. The settling stability of the cement slurries was measured, and the results of the cement slurry settling stability test are shown in Table 1. As can be seen from Table 1, the density difference between the upper, middle and lower parts of the elastic and tough foamed cement slurries of different densities can be controlled within ±0.03 g / cm³, which meets the technical requirements of the field.

[0037] According to GB / T19139-2012 Test Methods for Cement in Oil Wells, the compressive strength of cement stone was compared between the elastic and tough foamed cement slurry obtained in Examples 16 to 18 and the conventional foamed cement slurry obtained in Comparative Examples 1 to 3. The cement stone was cured for 48 hours and 7 days respectively, and the compressive strength was measured. The experimental results are shown in Table 2. As can be seen from Table 2, the compressive strength of the elastic and tough foamed cement slurry under different formulation conditions is better than that of the conventional foamed cement slurry of the same density, which meets the technical requirements of the field.

[0038] According to the "SY / T6466-2016 Test Method for Performance of Cement Stone in Oil Wells", a comparative experiment was conducted between the elastic and tough foamed cement slurries obtained in Examples 16 to 18 and the conventional foamed cement slurries obtained in Comparative Examples 1 to 3. Young's modulus was measured after 7 days of curing. The experimental results are shown in Table 3. As can be seen from Table 3, the Young's modulus of the elastic and tough foamed cement slurries with different formulations and densities is superior to that of the conventional foamed cement slurry, meeting the on-site technical requirements.

[0039] Therefore, this invention adds the required amount of elastic material and silica powder to cement, forming an effective particle size distribution between the solid materials of different particle sizes and the cement, thereby improving the compressive strength of low-density cement stone. At the same time, due to the film-forming properties of the elastic material, the generation and development of microcracks inside the cement stone are limited, thus improving the impact toughness. By adding foaming agents and foam stabilizers, the cement slurry is filled with uniform and dense air bubbles. Stable air bubbles can significantly reduce the density of the cement slurry, resulting in a more widely applicable elastic and tough foamed cement slurry. This elastic and tough foamed cement slurry solves the technical problem of cementing stability and leakage prevention in low-pressure and easily leaking formations, while also meeting the technical requirements of cement stone for subsequent fracturing and stimulation, achieving dual optimization of recovery rate and production life.

[0040] In summary, this invention provides an elastic and resilient foamed cement slurry and its preparation method. The raw materials for this cement slurry are simple and readily available, and the preparation is straightforward. It can meet the technical requirements of the field, and can effectively improve the cementing quality, especially in the cementing construction of gas storage facilities and low-pressure, easily leaking, and complex wells.

[0041] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A resilient foamed cement slurry, characterized in that... The raw materials, by weight, are: 100 parts cement, 5 to 20 parts lightweighting material, 10 to 20 parts elastic material, 5 to 15 parts silica fume, 5 to 15 parts water loss reducing agent, 2 to 8 parts retarder, 1 to 5 parts dispersant, 5 to 10 parts foaming agent, 1 to 5 parts foam stabilizer, and 50 to 70 parts water.

2. The elastic and resilient foamed cement slurry according to claim 1, characterized in that... The cement is one of medium sulfur-resistant cement or high sulfur-resistant cement; and / or the weight-reducing material is one or more of cenospheres, hollow glass microspheres, expanded perlite, and fly ash.

3. The elastic and resilient foamed cement slurry according to claim 1 or 2, characterized in that... The elastic material is one or more of latex particles, polyacrylonitrile fibers, and viscose fibers.

4. The elastic and resilient foamed cement slurry according to claim 1, 2, or 3, characterized in that... Silica powder is one of the 300 mesh, 500 mesh, and 1000 mesh silica sands.

5. The elastic and resilient foamed cement slurry according to claim 1, 2, 3, or 4, characterized in that... The water loss reducing agent is one of the following: a copolymer of sulfonated polystyrene, sulfonated polymethylstyrene, itaconic acid, and N-methyl-N-ethylacetamide, and a copolymer of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and acrylamide.

6. The elastic and resilient foamed cement slurry according to claim 1, 2, 3, 4, or 5, characterized in that... The retarder is one of the copolymers of 2-acrylamide-2-methylpropanesulfonic acid, itaconic acid, and acrylamide with copolymers of 2-acrylamide-2-methylpropanesulfonic acid, maleic acid, acrylic acid, and dimethyldiallylammonium chloride; or / and the dispersant is one of the copolymers of naphthalene sulfonate, naphthalene sulfonate condensate, sodium aminobenzenesulfonate, phenol, and formaldehyde; or / and the foaming agent is one of alkylphenol polyoxyethylene ether and sodium dodecylbenzenesulfonate; or / and the foam stabilizer is one or more of octyldecyl glycoside, lauramide propyl ammonium oxide, cocamidopropyl hydroxysulfobetaine, and sodium dodecyl sulfate; or / and the water is fresh water or brine with a concentration of 0 to 18%.

7. The elastic-toughness foamed cement slurry according to any one of claims 1 to 6, characterized in that... It was prepared according to the following method: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

8. The elastic and resilient foamed cement slurry according to claim 7, characterized in that... In the second step, the stirring speed is 1000r / min to 1200r / min. After adding the water loss reducer, retarder, and dispersant in sequence, the stirring time is 15s to 20s, 15s to 20s, and 20s to 25s, respectively. After adding the foaming agent and foam stabilizer, the stirring speed is adjusted to 2500r / min and stirred for 30s to 35s.

9. The elastic-toughness foamed cement slurry according to claim 7 or 8, characterized in that... In the third step, adjust the stirring speed to 3800 r / min to 4200 r / min, add the solid material to the slurry within 30 to 35 seconds, and continue stirring for 30 to 40 seconds after adding.

10. A method for preparing elastic and resilient foamed cement slurry according to any one of claims 1 to 6, 8 to 9, characterized in that... Perform the following steps: The first step is to mix the required amounts of cement, lightweighting material, elastic material, and silica powder evenly to obtain a solid material. The second step is to add the required amounts of water loss reducer, retarder, dispersant, foaming agent and foam stabilizer to the water in sequence, stir and mix evenly to obtain the slurry solution; The third step is to add the solid material to the slurry and stir it evenly to obtain elastic and tough foamed cement slurry.

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