A high temperature resistant cement and cement slurry system for cementing and a method of preparing the same

Abstract

This invention provides a high-temperature resistant cement and cement slurry system for well cementing and its preparation method. The high-temperature resistant cement for well cementing comprises the following components by weight: 40-55 parts of Grade G oil well cement, 40-55 parts of low-calcium silicate cement, 1-5 parts of gypsum, 1-10 parts of sulfoaluminate cement, and 1-10 parts of composite admixture. The high-temperature resistant cement slurry system for well cementing of this invention comprises the following components by weight: 100 parts of high-temperature resistant cement for well cementing, 0-70 parts of quartz sand, 1-6 parts of suspension stabilizer, 2-9 parts of fluid loss reducer, 0.5-1.5 parts of dispersant, 1-9 parts of retarder, 0.1-0.5 parts of defoamer, and 40-100 parts of water. The cement and cement slurry system of this invention is applicable to temperatures ranging from 150℃ to 240℃. After 28 days of curing, the compressive strength of the cement stone is greater than 40 MPa, and its compressive strength does not decline, ensuring the cementing sealing effect in high-temperature, ultra-high-temperature deep wells, and ultra-deep wells.

Description

Technical Field

[0001] This invention relates to a high-temperature resistant cement and cement slurry system for cementing and its preparation method, belonging to the field of oil and gas exploration and development. Background Technology

[0002] As exploration and development deepen, high-temperature and ultra-high-temperature deep wells are becoming increasingly common, with drilling depths gradually approaching tens of thousands of meters, and bottom-hole circulation temperatures gradually reaching ultra-high temperatures of 240°C. Under high-temperature and ultra-high-temperature conditions, the strength degradation of silicate cement stone is a serious problem, posing a significant challenge to ensuring the integrity of the cement sheath seal. Currently, the common approach is to select appropriate siliceous admixtures such as quartz sand and mix them with silicate cement. However, under temperatures above 200°C, the hydration products of sand-added cement change, resulting in significant strength degradation, which cannot meet the requirements of long-term production in high-temperature oil and gas wells. Therefore, it is necessary to develop a high-temperature resistant cement slurry system to prevent the strength degradation of cement stone at high temperatures, ensuring the safety of cementing operations in high-temperature deep wells and improving cementing quality.

[0003] CN112094060A discloses a high-temperature cementing cement, its preparation method, and its application. This cementing cement consists of 69-72% cement raw materials and 28-31% quartz sand. The cement raw materials are composed of Grade G oil well cement and nuclear power cement in a mass ratio of 4:6 to 5:5. However, this high-temperature cementing cement is mainly suitable for cementing projects in Africa, and its strength decreases slightly under conditions of 130℃ to 200℃.

[0004] CN101906291A discloses a high-temperature special oil well cement material and its preparation method. The oil well cement material comprises the following components in parts by weight: 100 parts high-belite cement, 10-25 parts quartz sand powder, and 0.22-0.32 parts lignin sulfonate or modified lignin sulfonate or 0.9-1.5 parts ethylenediaminetetramethylenephosphonate. This cement product has advantages such as high thermal stability and low pollution, but it is mainly used in oil and gas well workover projects, and its application scope is somewhat limited. It is only suitable for wells with a bottom hole circulation temperature of 60℃-130℃.

[0005] CN113582605A discloses a high-temperature resistant cementing system and its preparation method. This cementing system consists of 25-85 parts by weight of cement, 4-60 parts by weight of silica sand, 4-60 parts by weight of fly ash, and additives. This cementing system can solve the problem of strength degradation of cement stone in ultra-high temperature environments, and also solves the land occupation and environmental pollution problems caused by fly ash. Its applicable temperature can reach 200℃. However, after 30 days of curing, the compressive strength of the cement stone in this system shows a decrease compared to cement stone cured for 2 days.

[0006] CN115304317A discloses a high-temperature strength degradation resistant oil well cement slurry system. This cement slurry system consists of 47.5 wt%–72.5 wt% cementitious materials, 15 wt%–25 wt% silica sand, 10 wt%–25 wt% high-temperature strength degradation resistant materials, 2 wt% high-temperature stabilizer, and 0.5 wt% dispersant. This high-temperature strength degradation resistant oil well cement slurry system has the advantages of resisting high-temperature strength degradation and stable high-temperature performance, and can effectively alleviate the problem of strength degradation of cement stone under high-temperature conditions.

[0007] CN113683354A discloses a high-temperature strength degradation inhibitory oil well cement slurry system. By weight, the oil well cement slurry system comprises the following components: 100.0 parts oil well cement, 30.0–50.0 parts quartz sand, 10.0–20.0 parts high-temperature strength degradation inhibitor, 3.0–5.0 parts whisker material, 0.5–2.0 parts modified carbon nanotubes, 1.0–3.0 parts dispersant, 2–4 parts high-temperature stabilizer, 1.0–3.0 parts high-temperature water loss reducer, 3.0–5.0 parts high-temperature retarder, and 65.0–75.0 parts water. The high-temperature strength degradation inhibitor includes two or more of mica, kaolin, wollastonite, chlorite, and sepiolite. After curing at 240℃ for 90 days, the compressive strength of the cement stone in this cement slurry system is greater than 48MPa. However, high-temperature strength degradation inhibitors and modified carbon nanotubes may shorten the thickening time of the cement slurry to varying degrees, resulting in abnormal setting performance of the cement slurry and affecting the safety of cementing operations.

[0008] Currently, the cement used in the field of high-temperature strength degradation resistance is mostly aluminate cement, phosphate cement, or G-grade oil well cement with the addition of ultrafine silicate materials. While this reduces strength degradation at high temperatures, it does not fundamentally solve the problem of cement stone strength degradation. Conventional silicate cement stone exhibits strength degradation at curing temperatures around 110℃ because the hydration products transform from amorphous CSH gel to lower-performance crystalline dicalcium silicate hydrate. When the bottom-hole circulation temperature exceeds 110℃, adding silica to reduce the total calcium-silica ratio of the oil well cement can transform the cement hydration products into relatively high-performance calcium silicate and calcium silicate, thus maintaining stable strength. For many years, the optimal silica sand addition has been recognized as 30%–40% of the cement mass. However, recent studies have shown that in higher temperature environments (>150℃), silicate cement systems with added silica sand still exhibit significant microstructure coarsening and strength degradation; increasing the silica sand addition (50%–65%) at temperatures above 200℃ can alleviate severe strength degradation, but it still cannot fundamentally solve the problem. In recent years, adding high-temperature strength degradation resistant materials, such as metakaolin and sepiolite, to cement slurry can effectively prevent the strength degradation of cement stone under conditions of 150–200°C. However, in engineering applications, these high-temperature strength degradation resistant materials may affect the thickening time of the cement slurry, making it difficult to ensure the safety of cementing operations. Therefore, how to ensure the long-term strength stability of cement stone in environments above 200°C remains an urgent problem to be solved in cementing engineering.

[0009] Based on these issues, it is of great significance to develop a high-temperature resistant cement for cementing to prevent the strength degradation of cement stone under high temperature conditions of 200℃ and above. Summary of the Invention

[0010] To address the aforementioned technical problems, the present invention aims to provide a high-temperature resistant cement and cement slurry system for well cementing, and its preparation method. The high-temperature resistant cement and cement slurry system for well cementing provided by the present invention can prevent the strength degradation of cement stone under high and ultra-high temperature conditions.

[0011] To achieve the above objectives, the first aspect of the present invention provides a high-temperature resistant cement for cementing, comprising, by weight, the following components: 40-55 parts of Grade G oil well cement, 40-55 parts of low-calcium silicate cement, 1-5 parts of gypsum, 1-10 parts of sulfoaluminate cement, and 1-10 parts of composite admixture; wherein the composite admixture comprises a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10-15:5-10:3-6:1-3.

[0012] In the above-mentioned high-temperature cement for cementing, preferably, the weight ratio of G-grade oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixture is 40-50:40-50:1-3:5-10:3-6, more preferably 43:43:2:8:4.

[0013] In the above-mentioned high-temperature resistant cement for cementing, preferably, the weight ratio of carbide slag, phosphorus slag, mussel shell powder and sugar filter mud is 10-13:5-8:3-5:1-3.

[0014] In the above-mentioned high-temperature resistant cement for cementing, preferably, based on 100% of the total weight of the G-grade oil well cement, the G-grade oil well cement comprises the following components: 95%–97% silicate cement clinker and 3%–5% gypsum; wherein, based on 100% of the total weight of the silicate cement clinker, the silicate cement clinker comprises the following mineral composition: 40%–65% tricalcium silicate, 15%–25% dicalcium silicate, 10%–30% tricalcium aluminate and tetracalcium aluminoferrite, 1%–5% free calcium oxide and free magnesium oxide, and 0%–0.6% sodium oxide and potassium oxide.

[0015] In the aforementioned high-temperature resistant cement for cementing, preferably, based on 100% of the total weight of the low-calcium silicate cement, the low-calcium silicate cement comprises the following components: 94%–99% low-calcium silicate cement clinker and 1%–6% gypsum; wherein, based on 100% of the total weight of the low-calcium silicate cement clinker, the low-calcium silicate cement clinker comprises the following mineral composition: 45%–70% dicalcium silicate, 10%–40% tricalcium silicate, 10%–30% tricalcium aluminate and tetracalcium aluminoferrite, 1%–5% free calcium oxide and free magnesium oxide, and 0%–0.6% sodium oxide and potassium oxide.

[0016] In the above-mentioned high-temperature resistant cement for cementing, preferably, based on 100% of the total weight of the sulfoaluminate cement, the sulfoaluminate cement comprises the following components: 92% to 95% sulfoaluminate cement clinker and 5% to 8% gypsum; wherein, based on 100% of the total weight of the sulfoaluminate cement clinker, the sulfoaluminate cement clinker comprises the following mineral composition: 55% to 75% calcium sulfoaluminate, 8% to 37% dicalcium silicate, 15% to 35% tetracalcium aluminoferrite, 0% to 3% calcium sulfate, 1% to 5% free calcium oxide and free magnesium oxide, and 0% to 0.6% sodium oxide and potassium oxide.

[0017] In the aforementioned high-temperature resistant cement for cementing, preferably, the gypsum comprises one or a combination of several of the following: natural dihydrate gypsum, anhydrite (i.e., natural anhydrous gypsum), and mixed gypsum. Those skilled in the art should understand that mixed gypsum is any two or more gypsum raw materials (e.g., natural dihydrate gypsum, anhydrite, or various industrial by-product gypsum), prepared through processes such as thorough mixing, calcination, and grinding to form a homogeneous gypsum powder with cementing properties. This invention does not limit the specific composition of the mixed gypsum, which can be commercially available. The gypsum referred to herein includes gypsum in the components of high-temperature resistant cement for cementing, gypsum in the components of Grade G oil well cement, gypsum in the components of low-calcium silicate cement, and gypsum in the components of sulfoaluminate cement.

[0018] In the above-mentioned high-temperature resistant cement for cementing, preferably, the mass content of Ca(OH)2 in the carbide slag is 70% to 80%.

[0019] In the above-mentioned high-temperature resistant cement for cementing, preferably, the particle size of the carbide slag is 10-15 μm.

[0020] In the above-mentioned high-temperature resistant cement for cementing, preferably, the mass content of P2O5 in the phosphorus slag is 40% to 43%, the mass content of SiO2 is 47% to 52%, the mass content of Fe2O3 is 2% to 5%, the mass content of fluoride is 0.8% to 3%, and the mass content of Al2O3 is 0.8% to 2.5%.

[0021] In the above-mentioned high-temperature resistant cement for cementing, preferably, the particle size of the phosphorus slag is 0.5-5 mm.

[0022] In the above-mentioned high-temperature resistant cement for cementing, preferably, the CaCO3 content in the mussel shell powder is 90% to 96%.

[0023] In the above-mentioned high-temperature resistant cement for cementing, preferably, the particle size of the mussel shell powder is 200-300 μm.

[0024] In the above-mentioned high-temperature resistant cement for cementing, preferably, the mass content of CaCO3 in the sugar filter mud is 55% to 70%.

[0025] According to a specific embodiment of the present invention, the high-temperature resistant cement for cementing is prepared by the following steps: mixing G-grade oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement and composite admixtures evenly according to the above-mentioned weight proportions to obtain the high-temperature resistant cement for cementing.

[0026] The second aspect of the present invention provides a high-temperature resistant cement slurry system for cementing, comprising, by weight, the following components: 100 parts of the above-mentioned high-temperature resistant cement for cementing, 0-70 parts of quartz sand, 1-6 parts of suspension stabilizer, 2-9 parts of fluid loss reducer, 0.5-1.5 parts of dispersant, 1-9 parts of retarder, 0.1-0.5 parts of defoamer, and 40-100 parts of water.

[0027] In the aforementioned high-temperature resistant cement slurry system for cementing, preferably, the particle size of the quartz sand is 50 mesh to 5000 mesh. According to a specific embodiment of the present invention, the quartz sand includes ordinary quartz sand and / or acid-washed quartz sand.

[0028] In the aforementioned high-temperature resistant cement slurry system for cementing, the suspension stabilizer can be a conventional oil well cement suspension stabilizer, such as an acrylamide polymer suspension stabilizer. Preferably, the suspension stabilizer comprises a polymer suspension stabilizer prepared using 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, diallyl dimethylammonium chloride, and N-vinylpyrrolidone as monomers. This polymer suspension stabilizer can be prepared according to the steps disclosed in CN113736016A.

[0029] In the above-mentioned high-temperature resistant cement slurry system for cementing, the fluid loss reducing agent can be a conventional fluid loss reducing agent for oil well cement in the art, such as a polymeric fluid loss reducing agent based on 2-acrylamido-2-methylpropanesulfonic acid. Preferably, the fluid loss reducing agent comprises a polymeric fluid loss reducing agent prepared using 2-acrylamido-2-methylpropanesulfonic acid, N,N-dimethylacrylamide, and unsaturated carboxylic acid as monomers. The unsaturated carboxylic acid can be acrylic acid or itaconic acid, etc. This polymeric fluid loss reducing agent can be prepared by referring to, but not limited to, the steps disclosed in the synthesis and performance evaluation of salt-resistant fluid loss reducing agents AMPS / DMAA / IA (Yu Wenjuan et al., Chemical Industry and Engineering, 2018, 35(1):6).

[0030] In the above-described high-temperature resistant cement slurry system for cementing, the dispersant can be a conventional oil well cement dispersant used in the art. Preferably, the dispersant includes aldehyde-ketone condensate dispersants and / or polycarboxylic acid dispersants, etc.

[0031] In the above-mentioned high-temperature resistant cement slurry system for cementing, the retarder can be a conventional oil well cement retarder in the art. Preferably, the retarder includes one or a combination of several of hydroxyethylidene diphosphonic acid (HEDP), ethylenediaminetetramethylenephosphonic acid (EDTMPA), and ethylenediaminetetramethylenephosphonate.

[0032] In the aforementioned high-temperature resistant cement slurry system for cementing, the defoamer can be a conventional defoamer for oil well cement. Preferably, the defoamer includes one or a combination of several of the following: tributyl phosphate, polyoxypropylene glycerol ether, and polydimethylsiloxane.

[0033] According to a specific embodiment of the present invention, the above-mentioned high-temperature resistant cement slurry system for cementing is prepared by dry mixing and wet mixing of each component in dry and wet states, and then mixing the dry mixture and the wet mixture. Preferably, the above-mentioned high-temperature resistant cement slurry system for cementing is prepared by the following steps: high-temperature resistant cement for cementing, quartz sand, suspension stabilizer, and dispersant are mixed evenly according to the above-mentioned weight parts to obtain a dry mixture; a fluid loss reducing agent, retarder, defoamer, and water are mixed evenly according to the above-mentioned weight parts to obtain a wet mixture; the dry mixture is evenly poured into the wet mixture at a rotation speed of 4000±200 r / min, and after the dry mixture is completely added to the wet mixture, the rotation speed is adjusted to 12000±500 r / min, and stirring is continued for 15-35 s to obtain the high-temperature resistant cement slurry system for cementing.

[0034] A third aspect of the present invention provides a method for preparing the above-mentioned high-temperature resistant cement slurry system for cementing, comprising the following steps:

[0035] High-temperature cement for cementing, quartz sand, suspension stabilizer, and dispersant are mixed evenly according to their weight parts to obtain a dry mixture; fluid loss reducer, retarder, defoamer, and water are mixed evenly according to their weight parts to obtain a wet mixture; the dry mixture is evenly poured into the wet mixture at a rotation speed of 4000±200 r / min. After the dry mixture is completely added to the wet mixture, the rotation speed is adjusted to 12000±500 r / min, and stirring is continued for 15 to 35 seconds to obtain the high-temperature cement slurry system for cementing.

[0036] The technical solution of the present invention has at least the following beneficial effects:

[0037] (1) Under ultra-high temperature conditions of 240℃, conventional sand-added cement stone exhibits a significant decrease in the density of the interlocking network structure of needle-like calcium silicate crystals in the hydration products as the high-temperature curing period increases. This coarsening of the calcium silicate crystals leads to a severe reduction in the high-temperature mechanical properties of the sand-added oil well cement stone. This invention optimizes the calcium-silica-alumina ratio of the cement by compounding G-grade oil well cement, low-calcium silicate cement, sulfoaluminate cement, gypsum, and composite admixtures, thereby optimizing the composition of the hydration products and effectively improving the mechanical properties of the cement stone at high temperatures. This invention uses a composite admixture, which is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10–15:5–10:3–6:1–3. The composite admixture designed in this invention effectively improves the high-temperature strength degradation resistance of the cement stone. The cement formulation design of this invention can prevent the coarsening of hydration product grains, maintain the interlocking network structure of grains, and ensure the dense structure formed by the hard silicate calcium stone in the main hydration products, which plays a key role in improving the mechanical properties of high-temperature cement stone.

[0038] (2) Conventional G-grade oil well cement-sand systems require the addition of reinforcing materials and anti-strength degradation materials to achieve the effect of no strength degradation of cement stone under high temperature conditions. However, there are many types of reinforcing materials and anti-strength degradation materials, which are expensive. Special cements such as phosphate and aluminate cements require special admixtures, which have high research and development costs and poor economic efficiency. The high-temperature resistant cement components for cementing of this invention include G-grade oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixtures. The composite admixtures include a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10-15:5-10:3-6:1-3. The raw materials used in this invention are cement, gypsum, and solid waste, which are inexpensive and effectively save engineering costs.

[0039] (3) The high-temperature resistant cement for cementing provided by this invention can be combined with only basic admixtures such as quartz sand and silicate cement to form a high-temperature resistant cement slurry system for cementing. The thickening time of the high-temperature resistant cement slurry system for cementing of this invention is adjustable, and there is no need to add reinforcing materials or materials to prevent strength degradation. This avoids the problems of excessive admixtures in the cement slurry system leading to unadjustable thickening time, slurry thickening, and thus affecting the safety of cementing construction.

[0040] In summary, this invention provides a high-temperature resistant cement and cement slurry system for well cementing and its preparation method. The cement and cement slurry system of this invention is applicable to a bottom-hole circulation temperature range of 150℃ to 240℃. Within this temperature range, the compressive strength of the cement stone cured for 28 days is greater than 40 MPa, and there is no decrease in compressive strength compared to cement stone cured for 2 days, thus solving the problem of cement stone strength degradation above 200℃ affecting high-quality exploration and development. Simultaneously, the high-temperature resistant cement slurry system of this invention has a suitable thickening time, avoiding the problem of abnormal setting and regulating properties of the cement slurry due to excessively short thickening time. The high-temperature resistant cement and cement slurry system provided by this invention ensures the cementing sealing effect and cementing construction safety under high-temperature, ultra-high-temperature, and ultra-deep well conditions, improving cementing quality. Detailed Implementation

[0041] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0042] In the following examples and comparative examples, the raw materials used include Grade G oil well cement (high sulfate resistance type), low-calcium silicate cement, anhydrite, natural dihydrate gypsum, sulfoaluminate cement, carbide slag, phosphorus slag, mussel shell powder, sugar filter mud, quartz sand, suspension stabilizer, retarder, fluid loss reducer, dispersant, and defoamer, all of which are commercially available. The water used is distilled water.

[0043] Of which, based on the total weight of G-grade oil well cement as 100%, its composition is: 96% silicate cement clinker and 4% gypsum; based on the total weight of silicate cement clinker as 100%, its mineral composition is: 54% tricalcium silicate, 23% dicalcium silicate, 2% tricalcium aluminate, 17% tetracalcium aluminoferrite, 1.7% free calcium oxide, 2% free magnesium oxide, 0.1% sodium oxide and 0.2% potassium oxide.

[0044] Based on the total weight of 100% of low-calcium silicate cement, its composition is: 97% low-calcium silicate cement clinker and 3% gypsum; based on the total weight of 100% of low-calcium silicate cement clinker, its mineral composition is: 49% dicalcium silicate, 29% tricalcium silicate, 2% tricalcium aluminate, 16% tetracalcium aluminoferrite, 2.1% free calcium oxide, 1.6% free magnesium oxide, 0.1% sodium oxide and 0.2% potassium oxide.

[0045] Based on the total weight of sulfoaluminate cement as 100%, its composition is: 94% sulfoaluminate cement clinker and 6% gypsum; based on the total weight of sulfoaluminate cement clinker as 100%, its mineral composition is: 64% calcium sulfoaluminate, 16% dicalcium silicate, 15% tetracalcium aluminoferrite, 2.1% free calcium oxide, 2.7% free magnesium oxide, 0.1% sodium oxide and 0.1% potassium oxide.

[0046] The gypsum in the components of G-grade oil well cement, low-calcium silicate cement, and sulfoaluminate cement is a mixture of anhydrite and natural dihydrate gypsum at a mass ratio of 1:1.

[0047] The mass content of Ca(OH)2 in calcium carbide slag is 70%–80%. The particle size of calcium carbide slag is 10–15 μm.

[0048] The phosphorus slag contains 40%–43% P2O5, 47%–52% SiO2, 2%–5% Fe2O3, 0.8%–3% fluorides, and 0.8%–2.5% Al2O3. The particle size of the phosphorus slag is 0.5–5 mm.

[0049] The CaCO3 content in mussel shell powder is 90%–96%. The particle size of mussel shell powder is 200–300 μm.

[0050] The mass content of CaCO3 in sugar filter mud is 55%–70%.

[0051] The suspension stabilizer is a product of China Petroleum Engineering Technology Research Institute Co., Ltd., model DRK-3S.

[0052] The retarder is a product of China Petroleum Engineering Technology Research Institute Co., Ltd., model DRH-3L.

[0053] The fluid loss reducer is a product of China Petroleum Engineering Technology Research Institute Co., Ltd., model DRF-3L.

[0054] The dispersant is a product of China Petroleum Engineering Technology Research Institute Co., Ltd., model DRS-2S.

[0055] The defoamer is a product of China Petroleum Engineering Technology Research Institute Co., Ltd., model DRX-1L.

[0056] Example 1

[0057] This embodiment provides a high-temperature resistant cement for well cementing, comprising the following components by weight: 43 parts of Grade G oil well cement, 43 parts of low-calcium silicate cement, 2 parts of gypsum, 8 parts of sulfoaluminate cement, and 4 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0058] This embodiment also provides a high-temperature resistant cement slurry system for cementing, which, by weight, comprises the following components: 100 parts of high-temperature resistant cement for cementing in this embodiment, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducing agent, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 .

[0059] The high-temperature resistant cement slurry system for cementing in this embodiment is prepared by the following steps: High-temperature resistant cement, quartz sand, suspension stabilizer, and dispersant are mixed evenly according to the above-mentioned weight proportions to obtain a dry mixture; a fluid loss reducer, retarder, defoamer, and water are mixed evenly according to the above-mentioned weight proportions to obtain a wet mixture; using a mixer at a speed of 4000±200 r / min, the dry mixture is evenly poured into the wet mixture. After the dry mixture is completely added to the wet mixture, the mixer lid is closed, the speed is adjusted to 12000±500 r / min, and mixing continues for 35 seconds to obtain the high-temperature resistant cement slurry system for cementing.

[0060] Example 2

[0061] This embodiment provides a high-temperature resistant cement slurry system for cementing, comprising the following components by weight: 100 parts of the high-temperature resistant cement for cementing provided in Example 1, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 4 parts of suspension stabilizer, 5 parts of fluid loss reducer, 1.2 parts of dispersant, 5 parts of retarder, 0.2 parts of defoamer, and 49 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 The preparation steps for this high-temperature resistant cement slurry system for cementing are the same as in Example 1.

[0062] Example 3

[0063] This embodiment provides a high-temperature resistant cement slurry system for cementing, comprising the following components by weight: 100 parts of the high-temperature resistant cement for cementing provided in Example 1, 4 parts of suspension stabilizer, 3 parts of fluid loss reducer, 1 part of dispersant, 2 parts of retarder, 0.2 parts of defoamer, and 39 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³.3 The preparation steps for this high-temperature resistant cement slurry system for cementing are the same as in Example 1.

[0064] Example 4

[0065] This embodiment provides a high-temperature resistant cement for well cementing, comprising the following components by weight: 55 parts of Grade G oil well cement, 40 parts of low-calcium silicate cement, 1 part of gypsum, 2 parts of sulfoaluminate cement, and 2 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0066] This embodiment also provides a high-temperature resistant cement slurry system for cementing, which, by weight, comprises the following components: 100 parts of high-temperature resistant cement for cementing in this embodiment, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducing agent, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 .

[0067] Example 5

[0068] This embodiment provides a high-temperature resistant cement for well cementing, comprising the following components by weight: 40 parts of Grade G oil well cement, 55 parts of low-calcium silicate cement, 1 part of gypsum, 2 parts of sulfoaluminate cement, and 2 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0069] This embodiment also provides a high-temperature resistant cement slurry system for cementing, which, by weight, comprises the following components: 100 parts of high-temperature resistant cement for cementing in this embodiment, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducing agent, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 .

[0070] Example 6

[0071] This embodiment provides a high-temperature resistant cement for well cementing, comprising the following components by weight: 40 parts of Grade G oil well cement, 40 parts of low-calcium silicate cement, 5 parts of gypsum, 5 parts of sulfoaluminate cement, and 10 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0072] This embodiment also provides a high-temperature resistant cement slurry system for cementing, which, by weight, comprises the following components: 100 parts of high-temperature resistant cement for cementing in this embodiment, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducing agent, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 .

[0073] Example 7

[0074] This embodiment provides a high-temperature resistant cement for well cementing, comprising the following components by weight: 40 parts of Grade G oil well cement, 40 parts of low-calcium silicate cement, 5 parts of gypsum, 5 parts of sulfoaluminate cement, and 10 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 15:10:6:3. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0075] This embodiment also provides a high-temperature resistant cement slurry system for cementing, which, by weight, comprises the following components: 100 parts of high-temperature resistant cement for cementing in this embodiment, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducing agent, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this high-temperature resistant cement slurry system for cementing is 1.90 g / cm³. 3 .

[0076] Comparative Example 1

[0077] This comparative example provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of Grade G oil well cement, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducer, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this cement slurry system is 1.90 g / cm³. 3 The preparation steps for this cement slurry system are the same as in Example 1.

[0078] Comparative Example 2

[0079] This comparative example provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of Grade G oil well cement, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 4 parts of suspension stabilizer, 5 parts of fluid loss reducer, 1.2 parts of dispersant, 5 parts of retarder, 0.2 parts of defoamer, and 49 parts of water. The density of this cement slurry system is 1.90 g / cm³. 3 The preparation steps for this cement slurry system are the same as in Example 1.

[0080] Comparative Example 3

[0081] This comparative example provides a cement for well cementing, comprising the following components by weight: 34 parts of Grade G oil well cement, 52 parts of low-calcium silicate cement, 4 parts of gypsum, 6 parts of sulfoaluminate cement, and 4 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture of anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0082] This comparative example also provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of cement for well cementing of this comparative example, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 4 parts of suspension stabilizer, 5 parts of fluid loss reducer, 1.2 parts of dispersant, 5 parts of retarder, 0.2 parts of defoamer, and 49 parts of water. The density of this cement slurry system for well cementing is 1.90 g / cm³. 3 The preparation steps for this cement slurry system are the same as in Example 1.

[0083] Comparative Example 4

[0084] This comparative example provides a cement for well cementing, comprising, by weight, the following components: 52 parts of Grade G oil well cement, 34 parts of low-calcium silicate cement, 5 parts of gypsum, 5 parts of sulfoaluminate cement, and 4 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The gypsum is a mixture obtained by mixing anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0085] This comparative example also provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of cement for well cementing of this comparative example, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 4 parts of suspension stabilizer, 5 parts of fluid loss reducer, 1.2 parts of dispersant, 5 parts of retarder, 0.2 parts of defoamer, and 49 parts of water. The density of this cement slurry system for well cementing is 1.90 g / cm³. 3The preparation steps for this cement slurry system are the same as in Example 1.

[0086] Comparative Example 5

[0087] This comparative example provides a cement for well cementing, comprising, by weight, the following components: 43 parts of Grade G oil well cement, 43 parts of low-calcium silicate cement, 2 parts of gypsum, 8 parts of sulfoaluminate cement, and 4 parts of composite admixture; wherein the composite admixture is a mixture of carbide slag, phosphorus slag, and mussel shell powder in a weight ratio of 20:4:2. The gypsum is a mixture obtained by mixing anhydrite and natural dihydrate gypsum in a mass ratio of 1:1.

[0088] This comparative example also provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of cement for well cementing of this comparative example, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducer, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this cement slurry system for well cementing is 1.90 g / cm³. 3 The preparation steps for this cement slurry system are the same as in Example 1.

[0089] Comparative Example 6

[0090] This comparative example provides a cement for well cementing, which, by weight, comprises the following components: 45 parts of Grade G oil well cement, 45 parts of low-calcium silicate cement, 2 parts of gypsum, and 8 parts of sulfoaluminate cement. The gypsum is a mixture obtained by mixing anhydrite and natural dihydrate gypsum in a 1:1 mass ratio.

[0091] This comparative example also provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of cement for well cementing of this comparative example, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 3 parts of suspension stabilizer, 4 parts of fluid loss reducer, 1.2 parts of dispersant, 3 parts of retarder, 0.2 parts of defoamer, and 51 parts of water. The density of this cement slurry system for well cementing is 1.90 g / cm³. 3 The preparation steps for this cement slurry system are the same as in Example 1.

[0092] Comparative Example 7

[0093] This comparative example provides a cement slurry system for well cementing, comprising the following components by weight: 100 parts of cement for well cementing as provided in Comparative Example 6, 30 parts of 200-mesh ordinary quartz sand, 20 parts of 1500-mesh ordinary quartz sand, 4 parts of suspension stabilizer, 5 parts of fluid loss reducer, 1.2 parts of dispersant, 5 parts of retarder, 0.2 parts of defoamer, and 49 parts of water. The density of this cement slurry system is 1.90 g / cm³. 3The preparation steps for this cement slurry system are the same as in Example 1.

[0094] Test case

[0095] The thickening time and compressive strength of the cement slurry systems provided in Examples 1-7 and Comparative Examples 1-7 were tested according to standard GB / T 19139-2012 "Test Methods for Oil Well Cement". The main experimental instruments used in the testing process included: a 30-60 type corrugated agitator (CHANDLER Corporation, USA), an 8240 type high-temperature and high-pressure thickener (CHANDLER Corporation, USA), and an ultra-high temperature curing autoclave (Shenyang Taige Petroleum Instrument Equipment Manufacturing Co., Ltd.). The test results are shown in Table 1.

[0096] Table 1

[0097]

[0098] As shown in Table 1, under 200℃ conditions, the compressive strength of the cement stone in the ordinary G-grade oil well cement-sand slurry system provided in Comparative Example 1, cured for 28 days, significantly decreased compared to the compressive strength of the cement stone cured for 2 days. Comparing Example 1 and Comparative Example 1, it can be seen that, with a small difference in thickening time, the cement stone strength of the high-temperature resistant cement slurry system for cementing in Example 1 was 45.8 MPa after 2 days of curing and 53.8 MPa after 28 days of curing. This proves that the cement slurry system of Example 1 did not experience strength degradation under 200℃ conditions, and the 2-day and 28-day compressive strengths of the cement stone were both higher than those of the G-grade oil well cement-sand slurry system in Comparative Example 1. Furthermore, the thickening time of the cement slurry system in Example 1 was adjustable, and the thickening curve was normal, meeting the engineering performance requirements.

[0099] Under 240℃ conditions, the compressive strength of the cement stone in the ordinary G-grade oil well cement-sand slurry system provided in Comparative Example 2, after 28 days of curing, showed a significant decrease compared to the compressive strength of the cement stone after 2 days of curing. Comparing Example 2 and Comparative Example 2, it can be seen that, with a small difference in thickening time, the cement stone strength of the high-temperature resistant cement slurry system for cementing in Example 2 was 48.4 MPa after 2 days of curing, and 56.1 MPa after 28 days of curing. This proves that the cement slurry system of Example 2 did not experience strength degradation under ultra-high temperature conditions of 240℃, and the compressive strength of the cement stone after 2 days and 28 days was higher than that of the G-grade oil well cement-sand slurry system provided in Comparative Example 2.

[0100] At 150℃, the compressive strength of the cement stone in the sand-free cementing high-temperature resistant cement slurry system provided in Example 3, after 28 days of curing, is still greater than 40MPa, and there is no decline in compressive strength compared to the cement stone cured for 2 days.

[0101] In Examples 2, 3, and 4, the weight ratios of G-grade oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixture in the cementitious cement were 43:43:2:8:4, 34:52:4:6:4, and 52:34:5:5:4, respectively. At 240°C, the cement prepared in Example 2 with the weight ratio of G-grade oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixture (43:43:2:8:4) exhibited the highest compressive strength of the cement stone. In contrast, the weight ratios of the components in the cement formulations of Comparative Examples 3 and 4 were outside the scope of this invention, resulting in lower compressive strength of the cement stone. The 28-day compressive strength of the cement stone in Examples 2 and Comparative Examples 3 and 4 showed no decline compared to the 2-day compressive strength. This demonstrates that cement for cementing, prepared from Grade G oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixtures, helps improve the mechanical properties of cement stone under high-temperature conditions and prevents the degradation of cement stone's high-temperature strength. However, the mixing ratio of the components in the cement of this invention yields the most significant improvement in the mechanical properties of the cement stone. Furthermore, the optimal weight ratio of Grade G oil well cement, low-calcium silicate cement, gypsum, sulfoaluminate cement, and composite admixtures in the high-temperature resistant cement for cementing of this invention is 43:43:2:8:4.

[0102] The composite admixture in the high-temperature cement for cementing in Example 1 was a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The composite admixture in the cement for cementing in Comparative Example 5 was a mixture of carbide slag, phosphorus slag, and mussel shell powder in a weight ratio of 20:4:2. The cement for cementing in Comparative Example 6 did not use any composite admixture. At 200°C, the cement stone of Example 1 exhibited the highest compressive strength, while the cement stone of Comparative Example 6 exhibited the lowest compressive strength; furthermore, the 28-day compressive strength of the cement stone in Examples 1 and Comparative Examples 5 and 6 showed no decline compared to the 2-day compressive strength. The high-temperature cement slurry systems for cementing in Examples 4–7 showed no strength decline at 200°C; and the 28-day compressive strength of the cement stone in Examples 4–7 was higher than that in Comparative Examples 5 and 6.

[0103] The composite admixture in the high-temperature cement for cementing in Example 2 was a mixture of carbide slag, phosphorus slag, mussel shell powder, and sugar filter mud in a weight ratio of 10:5:3:1. The cement for cementing in Comparative Example 7 did not use composite admixtures. At 240°C, the compressive strength of the cement stone in Example 2 was significantly higher than that in Comparative Example 7.

[0104] Therefore, it can be seen that using the weight ratio of the present invention to compound G-grade oil well cement, low-calcium silicate cement, gypsum, and sulfoaluminate cement can achieve a certain effect in preventing the high-temperature strength degradation of cement stone. Furthermore, the composite admixture designed in this invention has a significant effect on improving the mechanical properties of cement stone.

[0105] In summary, the high-temperature resistant cement and cement slurry system for cementing provided by this invention is suitable for bottom hole circulation temperatures ranging from 150℃ to 240℃. Within this temperature range, the compressive strength of cement stone cured for 28 days is greater than 40 MPa (the compressive strength of cement stone cured for 28 days using a sand-added cement slurry system is greater than 50 MPa), and there is no decrease in compressive strength compared to cement stone cured for 2 days. This solves the problem of cement stone strength degradation above 200℃ affecting high-quality exploration and development. Simultaneously, the high-temperature resistant cement slurry system for cementing of this invention has a suitable thickening time, and the thickening time is adjustable, avoiding the problem of abnormal setting and regulating properties of the cement slurry due to excessively short thickening times. The high-temperature resistant cement and cement slurry system for cementing provided by this invention ensures cementing sealing performance and cementing construction safety under high-temperature, ultra-high-temperature, and ultra-deep well conditions, improving cementing quality.

[0106] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A high temperature resistant cement for cementing well, comprising the following components in parts by weight: G-class oil well cement 40-55, low calcium silicate cement 40-55, gypsum 1-5, sulphoaluminate cement 1-10, composite admixture 1-10; wherein, The composite admixture comprises a mixture of carbide slag, phosphorous slag, mussel shell powder and sugar filter mud in a weight ratio of 10-15:5-10:3-6:1-3; The mass content of Ca(OH)2 in the carbide slag is 70-80%; The mass content of P2O5 in the phosphorous slag is 40-43%, the mass content of SiO2 is 47-52%, the mass content of Fe2O3 is 2-5%, the mass content of fluoride is 0.8-3%, and the mass content of Al2O3 is 0.8-2.5%; The content of CaCO3 in the mussel shell powder is 90-96%. The mass content of CaCO3 in the sugar filter mud is 55-70%.

2. The high temperature resistant cement for cementing wells according to claim 1, wherein, The G-grade oil well cement comprises the following components: 95-97% of silicate cement clinker and 3-5% of gypsum, with the total weight of the G-grade oil well cement being 100%; wherein the silicate cement clinker comprises the following mineral composition: 40-65% of tricalcium silicate, 15-25% of dicalcium silicate, 10-30% of tricalcium aluminate and tetracalcium aluminoferrite, 1-5% of free calcium oxide and free magnesium oxide, and 0-0.6% of sodium oxide and potassium oxide, with the total weight of the silicate cement clinker being 100%.

3. The high temperature resistant cement for cementing wells according to claim 1, wherein, The low-calcium silicate cement comprises the following components: 94-99% of low-calcium silicate cement clinker and 1-6% of gypsum, with the total weight of the low-calcium silicate cement being 100%; wherein the low-calcium silicate cement clinker comprises the following mineral composition: 45-70% of dicalcium silicate, 10-40% of tricalcium silicate, 10-30% of tricalcium aluminate and tetracalcium aluminoferrite, 1-5% of free calcium oxide and free magnesium oxide, and 0-0.6% of sodium oxide and potassium oxide, with the total weight of the low-calcium silicate cement clinker being 100%.

4. The high temperature resistant cement for cementing wells according to claim 1, wherein, The total weight of the sulphoaluminate cement is 100%, and the sulphoaluminate cement comprises the following components: 92-95% of sulphoaluminate cement clinker and 5-8% of gypsum; wherein the sulphoaluminate cement clinker comprises the following mineral composition: 55-75% of calcium sulphoaluminate, 8-37% of dicalcium silicate, 15-35% of tetracalcium aluminoferrite, 0-3% of calcium sulphate, 1-5% of free calcium oxide and free magnesium oxide, and 0-0.6% of sodium oxide and potassium oxide.

5. The high temperature resistant cement for cementing wells according to any one of claims 1-4, wherein, The gypsum comprises one or a combination of natural dihydrate gypsum, hard gypsum and mixed gypsum.

6. The high temperature resistant cement for cementing wells according to claim 1, wherein, The particle size of the carbide slag is 10-15 μm.

7. The high temperature resistant cement for cementing wells according to claim 1, wherein, The particle size of the phosphorous slag is 0.5-5 mm.

8. The high temperature resistant cement for cementing wells according to claim 1, wherein, The particle size of the mussel shell powder is 200-300 μm.

9. A high-temperature resistant cement slurry system for cementing, comprising, by weight parts, the high-temperature resistant cement for cementing according to any one of claims 1-8 100 parts, quartz sand 0-70 parts, a suspension stabilizer 1-6 parts, a fluid loss additive 2-9 parts, a dispersant 0.5-1.5 parts, a retarder 1-9 parts, an antifoaming agent 0.1-0.5 parts, and water 40-100 parts.

10. The high temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The quartz sand has a particle size of 50 mesh to 5000 mesh, and the quartz sand comprises ordinary quartz sand and / or acid-washed quartz sand.

11. The high temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The suspension stabilizer comprises an acrylamide polymer suspension stabilizer.

12. The high-temperature resistant cement slurry system for cementing wells according to claim 9 or 11, wherein, The suspension stabilizer comprises a polymer suspension stabilizer prepared from 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, diallyldimethylammonium chloride, and N-vinylpyrrolidone as monomers.

13. The high-temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The fluid loss additive comprises a 2-acrylamido-2-methylpropanesulfonic acid polymer fluid loss additive.

14. The high-temperature resistant cement slurry system for cementing wells according to claim 9 or 13, wherein, The fluid loss additive comprises a polymer fluid loss additive prepared from 2-acrylamido-2-methylpropanesulfonic acid, N,N-dimethylacrylamide, and an unsaturated carboxylic acid as monomers.

15. The high-temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The dispersant comprises an aldehyde-ketone polycondensate dispersant and / or a polycarboxylic acid dispersant.

16. The high-temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The retarder comprises a combination of one or more of hydroxyethylenediphosphonic acid, ethylenediaminetetramethylenephosphonic acid, and ethylenediaminetetramethylenephosphonic acid salt.

17. The high-temperature resistant cement slurry system for cementing wells according to claim 9, wherein, The antifoaming agent comprises a combination of one or more of tributyl phosphate, polyoxypropylene glycerol ether, and polydimethylsiloxane.

18. A method of preparing a high temperature resistant cement slurry system for cementing as claimed in any one of claims 9 to 17, comprising the steps of: The high-temperature resistant cement for cementing, the quartz sand, and the suspension stabilizer are mixed uniformly according to weight parts to obtain a dry mixture; the fluid loss additive, the retarder, the antifoaming agent, and the water are mixed uniformly according to weight parts to obtain a wet mixture; the dry mixture is poured into the wet mixture at a rotation speed of 4000±200 r / min, and after the dry mixture is completely added to the wet mixture, the rotation speed is adjusted to 12000±500 r / min, and the stirring is continued for 15-35 s to obtain the high-temperature resistant cement slurry system for cementing.

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