High adaptability high temperature cementing cement and high temperature cementing slurry

Abstract

The application discloses a high-adaptability high-temperature well cementing cement and a high-temperature well cementing slurry, and relates to the technical field of well cementing materials for oil and gas wells.The high-temperature well cementing cement is composed of cement clinker and gypsum, and the mineral composition of the cement clinker comprises, in weight parts, 15-30 parts of tricalcium silicate, 6-15 parts of beta-dicalcium silicate, 38-55 parts of gamma-dicalcium silicate, 0.5-1.5 parts of tricalcium aluminate, 10-16 parts of tetracalcium aluminoferrite-titanium dioxide and 0.5-4 parts of calcium oxide; and the content of titanium dioxide in raw materials of the cement clinker is 1-2 percent in weight percentage.The application changes the mode of cement mineral composition, improves the adaptability of the cement to additives under high-temperature and high-pressure conditions, reduces the adjustment difficulty of the thickening time of the high-temperature well cementing slurry, improves the working performance and stability of the high-temperature well cementing slurry, and achieves the purpose of improving the construction safety and well cementing quality of deep well high-temperature well cementing operation.

Description

Technical Field

[0001] This invention relates to the field of cementing materials for oil and gas wells, and more specifically to a highly adaptable high-temperature cementing cement and a high-temperature cementing slurry. Background Technology

[0002] In recent years, 60% of the world's newly added oil and gas reserves have come from deep strata. my country's deep and ultra-deep oil and gas resources amount to 67.1 billion tons of oil equivalent. In the Tarim Basin, oil and natural gas resources buried at depths of 6,000 to 10,000 meters account for 83.2% and 63.9% of the country's total, respectively. Currently, exploration is underway for ultra-deep oil and gas resources exceeding 10,000 meters. Deep and ultra-deep oil and gas will become an important area for increasing my country's oil and gas production.

[0003] As oil and gas exploration and development continue to expand into deeper formations, ultra-deep wells face increasingly higher temperature and pressure challenges. Deep oil and gas formations in my country are characterized by high temperature and pressure, and complex geological conditions, presenting significant challenges related to high temperature and high pressure. In particular, the combined effects of high temperature and high pressure pose unprecedented requirements and challenges to the safe pumping of cement slurry under these conditions. This manifests as abrupt changes in cement slurry thickening time and flash-setting phenomena under high temperature and high pressure, which in turn affect cementing quality and construction safety.

[0004] To ensure that cement slurry meets the requirements for cementing deep, high-temperature wells, a large amount of high-temperature retarders must be added. These retarders slow down the hydration rate of cement under high temperature and pressure conditions, allowing the slurry sufficient thickening time to meet construction requirements. In recent years, both domestic and international research and development of ultra-high temperature retarders has been strengthened, with significant progress made in polymer-based retarders. By leveraging the effectiveness of specific functional groups through molecular design, the high-temperature resistance of retarders has been improved. These retarders already exhibit good setting regulation and stability at 180℃ and below, meeting the requirements for current conventional deep well applications. However, with the further development of deep resources, future wellbore circulation temperatures will exceed 200℃. Current retarder systems suffer from poor stability and require high dosages at higher temperatures, seriously affecting the construction safety and cementing quality of deep wells. Summary of the Invention

[0005] To overcome the defects and shortcomings of the existing technology, this invention provides a highly adaptable high-temperature cementing cement and a high-temperature cementing slurry. The purpose of this invention is to solve the problems of poor admixture adaptability of existing cementing cements under high temperature and high pressure conditions and the difficulty in adjusting the thickening time of the cement slurry. This invention improves the admixture adaptability of cement under high temperature and high pressure conditions by changing the mineral composition of the cement, reduces the difficulty in adjusting the thickening time of the high-temperature cementing slurry, and improves the workability and stability of the high-temperature cementing slurry, thereby improving the construction safety and cementing quality of deep well high-temperature cementing operations.

[0006] To address the problems existing in the prior art, the present invention is achieved through the following technical solution.

[0007] The first aspect of this invention provides a highly adaptable high-temperature cementing cement, which is composed of cement clinker and gypsum, wherein the mineral composition of the cement clinker, in parts by weight, includes...

[0008] Tricalcium silicate: 15-30 parts;

[0009] β-Dicalcium silicate: 6-15 parts;

[0010] dicalcium γ-silicate: 38-55 parts;

[0011] Tricalcium aluminate: 0.5-1.5 parts;

[0012] Tetracalcium aluminoferrite-titanium dioxide: 10-16 parts;

[0013] Calcium oxide: 0.5-4 parts;

[0014] Among them, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1250℃-1350℃ during the preparation of cement clinker.

[0015] The amount of titanium dioxide in the raw materials of the cement clinker is 1%-2% by weight.

[0016] More preferably, the gypsum content in the high-temperature cementing is 2%-4% by weight.

[0017] More preferably, the thickening time of the high-temperature cementing cement at 100°C is 150-240 minutes.

[0018] More preferably, the cement clinker is silicate cement clinker.

[0019] A second aspect of the present invention provides a high-temperature cementing slurry, which comprises, by weight, the following components:

[0020] The high-temperature cementing cement mentioned in the first aspect: 68-75 parts;

[0021] Quartz powder: 25-32 parts;

[0022] High-temperature retarder: 2-4 parts;

[0023] High-temperature dehydration agent: 4-6 parts;

[0024] High temperature stabilizer: 0.5-2 parts.

[0025] More preferably, the high-temperature cement slurry has a thickening curve mutation value of less than 10 BC at 215℃, a thickening time of 400-500 min, a compressive strength of >35 MPa after curing at 260℃ for 7 days, and a compressive strength degradation rate of <5% after curing at 260℃ for 14 days.

[0026] More preferably, the silica content in the quartz powder is >97%, and the fineness is 200-350 mesh.

[0027] More preferably, the high-temperature retarder is an organic polymer-based high-temperature retarder.

[0028] More preferably, the high-temperature water loss reducing agent is an AMPS-type polymer water loss reducing agent.

[0029] More preferably, the high-temperature stabilizer is a hydrophobic associating polymer stabilizer.

[0030] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0031] This invention aims to improve the adaptability of high-temperature cementing admixtures and extend the thickening time of high-temperature cementing slurry by adjusting the mineral composition of silicate cement and changing the properties and structure of each mineral in silicate cement clinker.

[0032] Its specific mechanism of action is as follows:

[0033] 1. After silicate cement undergoes high-temperature calcination in a rotary kiln, β-dicalcium silicate (β-C2S) does indeed transform into γ-dicalcium silicate (γ-C2S) under specific conditions. Cooling rate is a key influencing factor. When the clinker cools at a slower temperature, sufficient time and suitable thermodynamic conditions are provided for the β-dicalcium silicate to undergo the crystal transformation, resulting in some β-dicalcium silicate transforming into γ-dicalcium silicate.

[0034] Silicate cement clinker minerals are not simply ideal compounds; they contain dissolved amounts of other elements or ions. When these dissolved metal ions, such as aluminum and iron, are present in the mineral, they alter the mineral's crystal structure and internal energy state. They occupy some positions within the crystal structure, making it more complex and irregular, unlike the simple crystal structure of β-dicalcium silicate. This structural change, in turn, affects the crystal transformation process.

[0035] For the transformation from β-dicalcium silicate to γ-dicalcium silicate, the structural changes brought about by the solid solution of metal ions such as aluminum and iron interfere with the energy transfer and atomic rearrangement processes required for the transformation, thus hindering the large-scale formation of γ-dicalcium silicate. In other words, the presence of the solid solution makes the crystal transformation not as easy as in the case of pure β-dicalcium silicate, limiting the final amount of γ-dicalcium silicate formed.

[0036] Because dicalcium γ-silicate hardly hydrates with water, only about 20% hydrates by 28 days, resulting in slow setting and hardening, which severely reduces the strength properties of silicate cement. Therefore, in commonly used silicate cement systems, the formation of dicalcium γ-silicate is minimized by increasing ion doping and solid solution treatment, and by increasing the cooling rate. Conventional production methods cannot produce silicate cement clinker with high dicalcium γ-silicate content.

[0037] This invention introduces titanium dioxide into the raw materials of cement clinker. During the high-temperature calcination of cement (1250℃-1350℃), titanium dioxide will accumulate. For aluminum oxide and ferric oxide, the accumulation of titanium dioxide changes the chemical environment and reaction kinetics of the system, thereby promoting the formation of tricalcium aluminate (C3A) from aluminum oxide and tetracalcium aluminoferrite (C4AF) from ferric oxide to a certain extent.

[0038] Because titanium dioxide promotes the formation of more tricalcium aluminate and tetracalcium aluminoferrite from aluminum oxide and ferric oxide, some of the metal ions that were originally dissolved in dicalcium silicate and tricalcium silicate (such as aluminum ions and iron ions from aluminum oxide and ferric oxide) will participate more in the formation of tricalcium aluminate and tetracalcium aluminoferrite, thereby reducing the solid solubility of these metal ions in dicalcium silicate and tricalcium silicate.

[0039] Normally, dissolved metal ions in dicalcium silicate (mainly β-dicalcium silicate) hinder the transformation of β-dicalcium silicate to γ-dicalcium silicate. This invention introduces titanium dioxide to reduce the solid solubility of metal ions in dicalcium silicate, which is equivalent to removing some of the factors that hinder the transformation of β-dicalcium silicate to γ-dicalcium silicate. As a result, the interference encountered by β-dicalcium silicate in the transformation to γ-dicalcium silicate under conditions such as cooling is reduced, thereby improving its transformation efficiency and increasing the amount of γ-dicalcium silicate formed, thus realizing the production of silicate cement clinker with high γ-dicalcium silicate content.

[0040] Dicalcium γ-silicate has an orthorhombic crystal system, space group Pbnm, and lattice constants a = 5.081 Å, b = 11.224 Å, and c = 6.778 Å. Its internal structure consists of silicon-oxygen tetrahedra connected by polyhedra to form a three-dimensional spatial structure. It exhibits few crystal defects and relatively stable chemical structure. This invention obtains cement clinker with a high dicalcium γ-silicate content and utilizes the slow hydration rate of dicalcium γ-silicate to extend the thickening time of cement under high-temperature conditions. This addresses the difficulty in adjusting the thickening time of high-temperature cementing slurry, thereby reducing the complexity of adjusting the thickening time of high-temperature cementing slurry.

[0041] 2. In this application, 1%-2% by weight of titanium dioxide is introduced into the raw materials of cement clinker. Part of the titanium dioxide promotes the formation of tricalcium aluminate (C3A) from aluminum oxide and tetracalcium aluminoferrite (C4AF) from ferric oxide. The other part of the titanium dioxide participates in the high-temperature reaction process of cement clinker minerals and dissolves in the tetracalcium aluminoferrite mineral phase to form a new mineral product, namely tetracalcium aluminoferrite-titanium dioxide.

[0042] First, due to its high chemical structural stability, titanium dioxide, when dissolved in the tetracalcium aluminoferrite mineral phase, enhances the structural stability of tetracalcium aluminoferrite. It fills some vacancies in the tetracalcium aluminoferrite crystal structure, making the crystal structure more compact and robust, thus effectively resisting damage from external factors (such as temperature changes and mechanical stress). Second, the solid solution of titanium dioxide in the tetracalcium aluminoferrite mineral phase affects factors closely related to the hydration process, such as surface energy and ion diffusion rate, ultimately altering the hydration activity of tetracalcium aluminoferrite.

[0043] The newly formed tetracalcium aluminoferrite-titanium dioxide mineral exhibits altered structure and hydration activity compared to the original tetracalcium aluminoferrite. In high-temperature environments, the original tetracalcium aluminoferrite, due to its structural characteristics and environmental conditions (such as high temperature and high humidity), readily meets the conditions for hydration and undergoes premature hydration. However, the tetracalcium aluminoferrite-titanium dioxide mineral, after titanium dioxide solid solution treatment, possesses a more stable structure and altered hydration activity, thus no longer easily meeting the conditions for premature hydration. This effectively prevents premature hydration of the mineral phase in high-temperature environments.

[0044] In high-temperature cementing slurry systems, premature hydration of the cement mineral phase is a major cause of abrupt changes in the thickening curve. By using titanium dioxide to prevent premature hydration of the tetracalcium aluminoferrite mineral phase, the series of impacts on the rheological properties of the cement slurry caused by premature hydration of this mineral phase are reduced at the source, thereby effectively reducing the problem of abrupt changes in the thickening curve of high-temperature cementing slurry.

[0045] 3. This invention improves the compatibility of high-temperature cementing with additives by reducing the content of highly reactive minerals (tricalcium silicate and tricalcium aluminate), increasing the content of minerals with high structural stability, reducing the overall hydration activity of high-temperature cementing, and extending the thickening time of high-temperature cementing. Attached Figure Description

[0046] Figure 1 This is a high-temperature thickening curve of the high-temperature cement slurry prepared by the high-temperature cementing cement in Example 1 of the present invention;

[0047] Figure 2 The XRD diffraction pattern of the highly adaptable high-temperature cementing cement prepared in Example 4 of this invention;

[0048] Figure 3 This is a scanning electron microscope image of cement clinker from Embodiment 4 of the present invention;

[0049] Figure 4 This is an EDS surface scan of titanium dioxide in cement clinker in Example 4 of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] Example 1

[0052] As a preferred embodiment of the present invention, this embodiment discloses a highly adaptable high-temperature cementing cement, which is composed of cement clinker and gypsum. The mineral composition of the cement clinker, by weight, includes...

[0053] 15 parts of tricalcium silicate;

[0054] 13 parts of dicalcium β-silicate;

[0055] 55 parts of dicalcium γ-silicate;

[0056] Tricalcium aluminate 0.5 parts;

[0057] 16 parts of tetracalcium aluminoferrite-titanium dioxide;

[0058] 0.5 parts calcium oxide;

[0059] Wherein, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1250℃ during the preparation of cement clinker.

[0060] By weight percentage, the amount of titanium dioxide in the raw materials of the cement clinker is 2%; the content of gypsum in the high-temperature cementing cement is 2%.

[0061] Example 2

[0062] As another preferred embodiment of the present invention, this embodiment discloses a highly adaptable high-temperature cementing cement, which is composed of cement clinker and gypsum. The mineral composition of the cement clinker, by weight, includes...

[0063] Tricalcium silicate 27.5 parts;

[0064] 6 parts of dicalcium β-silicate;

[0065] 48 parts of dicalcium γ-silicate;

[0066] Tricalcium aluminate 1.5 parts;

[0067] 13 parts of tetracalcium aluminoferrite-titanium dioxide;

[0068] 4 parts calcium oxide;

[0069] Wherein, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1300℃ during the preparation of cement clinker.

[0070] By weight percentage, the amount of titanium dioxide in the raw materials of the cement clinker is 1.5%; the content of gypsum in the high-temperature cementing cement is 4%.

[0071] Example 3

[0072] As another preferred embodiment of the present invention, this embodiment discloses a highly adaptable high-temperature cementing cement, which is composed of cement clinker and gypsum. The mineral composition of the cement clinker, by weight, includes...

[0073] 25 parts of tricalcium silicate;

[0074] 15 parts of dicalcium β-silicate;

[0075] 46 parts of dicalcium γ-silicate;

[0076] Tricalcium aluminate 1.2 parts;

[0077] 10 parts of tetracalcium aluminoferrite-titanium dioxide;

[0078] Calcium oxide 2.8 parts;

[0079] Wherein, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1300℃ during the preparation of cement clinker.

[0080] By weight percentage, the amount of titanium dioxide in the raw materials of the cement clinker is 1.5%; the content of gypsum in the high-temperature cementing cement is 3%.

[0081] Example 4

[0082] As another preferred embodiment of the present invention, this embodiment discloses a highly adaptable high-temperature cementing cement, which is composed of cement clinker and gypsum. The mineral composition of the cement clinker, by weight, includes...

[0083] 30 parts of tricalcium silicate;

[0084] 11 parts of dicalcium β-silicate;

[0085] 38 parts of dicalcium γ-silicate;

[0086] Tricalcium aluminate 1.5 parts;

[0087] 16 parts of tetracalcium aluminoferrite-titanium dioxide;

[0088] 3.5 parts calcium oxide;

[0089] Wherein, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1350℃ during the preparation of cement clinker.

[0090] By weight percentage, the amount of titanium dioxide in the raw materials of the cement clinker is 1.0%; the content of gypsum in the high-temperature cementing cement is 3.5%.

[0091] Comparative Example 1

[0092] To highlight the performance of the highly adaptable high-temperature cementing cement proposed in this invention, this comparative example is provided. In this comparative example, the cement clinker used is Grade D oil well cement, and its mineral composition is as follows:

[0093] Tricalcium silicate, 34.1 parts;

[0094] 45.6 parts of β-dicalcium silicate;

[0095] 3.5 parts of dicalcium γ-silicate;

[0096] Tricalcium aluminate 0.6 parts;

[0097] 15.8 parts of tetracalcium aluminoferrite

[0098] 0.5 parts of calcium oxide.

[0099] Test case

[0100] Based on Examples 1-4 and Comparative Example 1 above, the present invention proposes the following high-temperature cementing cement and high-temperature cementing slurry. The high-temperature cementing cements of Examples 1, 2, 3 and 4 are ground to a suitable fineness and then the cement slurry is prepared in accordance with the relevant provisions in GB / T19139. The mixing water accounts for 44% of the mass of the cementing cement, and the thickening time at 100°C is tested. The specific test results are shown in Table 1.

[0101] Table 1 shows the thickening test data of the cement prepared in Examples 1 to 4 and Comparative Example 1.

[0102]

[0103] Weigh cement, quartz powder, high-temperature retarder, high-temperature fluid loss reducer and high-temperature stabilizer according to the weight parts in Table 2 below, and prepare cement slurry according to the relevant provisions in GB / T 19139, wherein the mixing water accounts for 44% of the mass of cement.

[0104] In this invention, the high-temperature retarder is an organic polymer-based high-temperature retarder; the high-temperature water loss reducing agent is an AMPS-based polymer water loss reducing agent; and the high-temperature stabilizer is a hydrophobic associating polymer stabilizer. The high-temperature retarder and high-temperature water loss reducing agent used in the experimental examples of this invention are T613L and T816L from Puyang Minghua Chemical Co., Ltd., respectively. The high-temperature stabilizer used in the experimental examples of this invention is BCJ-300, a product of Tianjin Zhongyou Boxing Engineering Technology Co., Ltd. The silica content of the quartz powder used in the experimental examples of this invention is 98.4%.

[0105] It should be noted that the high-temperature retarder, high-temperature water loss reducer and high-temperature stabilizer in this invention can be replaced by commonly used high-temperature retarder, high-temperature water loss reducer and high-temperature stabilizer in the art, and are not limited to the products selected in this test example.

[0106] Table 2 shows the proportions of the cementing slurries prepared in Examples 1 to 4 and Comparative Example 1.

[0107]

[0108] The five types of cement slurry prepared in Table 2 were poured into thickening slurry cups. After the thickening slurry cups were sealed, they were placed in a pressure thickening apparatus. Then the lid of the apparatus was installed, and the thickening test scheme was set. The thickening temperature was 215℃, the heating time was 120min, and the thickening test pressure was 125MPa. After the pressure curing apparatus was filled with heat transfer oil, the high-temperature thickening test was started. The experimental results are shown in Table 3.

[0109] The five types of cement slurry prepared in Table 2 were poured into cement stone compressive strength molds and molded. The molds were cubes with a side length of 50 mm (or 2 inches). After filling the molds and covering them with a cover plate, they were immediately placed in a pressure curing autoclave. The autoclave was closed, water was added, and the pressure was increased to 20.7 MPa. The temperature was raised to the curing temperature of 260℃ after 4 hours. Heating was stopped 4 hours before the setting period. After the temperature inside the pressure curing autoclave dropped below 100℃, cooling water was turned on. 45 minutes before the strength test, the pressure was slowly released and the molds were removed from the curing autoclave. The molds were then immediately demolded and placed in a water bath at a temperature of 27℃±3℃ for cooling. The compressive strength of the cement stone was tested on time. The 14-day compressive strength degradation rate was the ratio of the difference between the 14-day compressive strength value and the 7-day compressive strength value to the 7-day compressive strength value. Specific test results are shown in Table 3.

[0110] Table 3 shows the thickening test and compressive strength test results of the cement slurries prepared in Examples 1 to 4 and Comparative Example 1.

[0111]

[0112] As shown in Table 1 above, under the same water-cement ratio, the thickening time of Examples 1-4 at 100℃ and 60MPa is all >168min, with the longest being 235min, indicating that the proportion of various minerals in the cement has a significant impact on the thickening time. Example 4 has a composition similar to the Grade D oil well cement in Comparative Example 1, but due to differences in the contents of β-dicalcium silicate, γ-dicalcium silicate, and titanium oxide, Example 4 has a longer thickening time, demonstrating that the cement thickening time can be effectively adjusted by changing the mineral crystal structure and chemical composition of the cement.

[0113] The test results in Table 3 show that, when the same additives are added, the thickening time of Examples 1-4 can be adjusted to over 400 minutes, effectively ensuring the operation time for high-temperature cementing operations in deep wells. Furthermore, the compressive strength after 7 days of curing at 260℃ is high, and the compressive strength decay after 14 days is small, effectively meeting the cementing requirements of high-temperature deep wells. Although Grade D oil well cement is a high-temperature cementing cement in GB / T 10238, the high-temperature thickening time at 215℃ is 225 minutes. The thickening time of the high-temperature cementing slurry prepared with Grade D oil well cement is still relatively short, resulting in relatively low high-temperature compressive strength.

[0114] Refer to the instruction manual appendix Figure 1 The figure shows the high-temperature thickening curve of the high-temperature cement slurry prepared by the high-adaptability high-temperature cementing cement in Example 1 at 215℃. The consistency of the cement slurry decreased with the increase of temperature, but the consistency value remained stable in the later stage. The consistency mutation value was small (3BC). The temperature and pressure curves were stable, indicating that the high-adaptability cementing cement has good working performance under the high temperature condition of 215℃.

[0115] Refer to the instruction manual appendix Figure 2 The image shows the XRD diffraction curve of the high-adaptability high-temperature cementing cement of Example 4. The cement contains tricalcium silicate, dicalcium β-silicate, dicalcium γ-silicate, tetracalcium aluminoferrite-titanium dioxide, calcium oxide and gypsum dihydrate, among which the diffraction peak of dicalcium γ-silicate is obvious.

[0116] Refer to the instruction manual appendix Figure 3 and attached Figure 4 As shown, attached Figure 3 Here is a scanning electron microscope (SEM) image of the cement clinker from Example 4, attached. Figure 4 The image shows an EDS (Electron Scanning Microscopy) image of titanium dioxide. The gray area in the scanning electron microscope image represents tetracalcium aluminoferrite. The results of the titanium dioxide EDS image show that after high-temperature calcination of cement clinker, titanium dioxide is mainly dissolved in the tetracalcium aluminoferrite mineral phase, forming a new type of tetracalcium aluminoferrite-titanium dioxide mineral, while the amount dissolved in the tricalcium silicate and dicalcium silicate mineral phases is relatively small.

[0117] In summary, this invention can improve the adaptability of admixtures and the high-temperature strength of high-temperature cementing cement, which is beneficial to improving the safety of high-temperature cementing operations in deep wells.

[0118] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention used to illustrate the technical solutions of the present invention, and are not intended to limit the invention, nor are they intended to limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. That is to say, any changes or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but whose technical problems are still consistent with the present invention, should be included within the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention to other related technical fields are similarly included within the patent protection scope of the present invention.

Claims

1. A highly adaptable high-temperature cementing cement, comprising cement clinker and gypsum, characterized in that: The mineral composition of the cement clinker, in parts by weight, includes Tricalcium silicate: 15-30 parts; β-Dicalcium silicate: 6-15 parts; dicalcium γ-silicate: 38-55 parts; Tricalcium aluminate: 0.5-1.5 parts; Tetracalcium aluminoferrite-titanium dioxide: 10-16 parts; Calcium oxide: 0.5-4 parts; Among them, the tetracalcium aluminoferrite-titanium dioxide is a product formed in the tetracalcium aluminoferrite mineral phase after the titanium dioxide in the raw materials of cement clinker is calcined at 1250℃-1350℃ during the preparation of cement clinker. The amount of titanium dioxide in the raw materials of the cement clinker is 1%-2% by weight.

2. The highly adaptable high-temperature cementing cement as described in claim 1, characterized in that: The gypsum content in the high-temperature cement is 2%-4% by weight.

3. A highly adaptable high-temperature cementing cement as described in claim 1 or 2, characterized in that: The thickening time of the high-temperature cementing cement at 100℃ is 150min-240min.

4. A highly adaptable high-temperature cementing cement as described in claim 1 or 2, characterized in that: The cement clinker is silicate cement clinker.

5. A high-temperature cementing slurry, characterized in that: This high-temperature cementing slurry comprises the following components by weight: The high-temperature cementing cement according to any one of claims 1-4: 68-75 parts; Quartz powder: 25-32 parts; High-temperature retarder: 2-4 parts; High-temperature dehydration agent: 4-6 parts; High temperature stabilizer: 0.5-2 parts.

6. The high-temperature cementing slurry as described in claim 5, characterized in that: The high-temperature cement slurry has a thickening curve mutation value of less than 10 BC at 215℃, a thickening time of 400-500 min, a compressive strength of >35 MPa after curing at 260℃ for 7 days, and a compressive strength degradation rate of <5% after curing at 260℃ for 14 days.

7. A high-temperature cementing slurry as described in claim 5 or 6, characterized in that: The quartz powder contains >97% silica and has a fineness of 200-350 mesh.

8. A high-temperature cementing slurry as described in claim 5 or 6, characterized in that: The high-temperature retarder is an organic polymer-based high-temperature retarder.

9. A high-temperature cementing slurry as described in claim 5 or 6, characterized in that: The high-temperature water loss reducing agent is an AMPS-type polymer water loss reducing agent.

10. A high-temperature cementing slurry as described in claim 5 or 6, characterized in that: The high-temperature stabilizer is a hydrophobic associative polymer stabilizer.

Images