A retentive self-supporting frac-catalytic cement slurry for hydrogen production from an aquifer reservoir
By combining a rigid porous core with a catalytic active layer in cement slurry and adding anti-corrosion, anti-hydrogen embrittlement, and high-temperature resistant components, the problem of instability of cement slurry under extreme environments in existing technologies has been solved, realizing an efficient, safe, and economical hydrogen production process for in-situ catalytic conversion of methane.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEST PETROLEUM UNIV
- Filing Date
- 2026-06-05
- Publication Date
- 2026-07-03
AI Technical Summary
In the existing technology, there is a lack of highly efficient catalytic fracturing cement that can work stably for a long time in the extreme environment downhole during the direct conversion of methane into hydrogen. In addition, traditional cement slurry cannot simultaneously achieve in-situ catalytic conversion of methane, high temperature resistance, hydrogen embrittlement resistance and corrosion resistance, resulting in a complex and unsafe process.
The retention self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs combines a rigid porous core with a catalytic active layer, and incorporates anti-corrosion, anti-hydrogen embrittlement, and high-temperature resistant components to form a multi-layered anti-failure protection system. It also constructs a through-penetration network to achieve integrated fracturing support and catalytic conversion.
It significantly improves the service stability of materials under extreme environments, extends the service life of aquifer gas storage facilities, reduces maintenance costs and safety accident risks, and ensures the continuous and efficient operation of in-situ methane hydrogen production reactions.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of hydrogen production technology for aquifer reservoirs, specifically relating to a retention self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs. Background Technology
[0002] Aquifer gas storage facilities are formed by injecting high-pressure gas into an aquifer, displacing water from the reservoir pores, and creating a gas storage site directly beneath the caprock. Aquifer gas storage facilities have large storage capacities, second only to depleted oil and gas reservoirs in size. With the increasing strategic importance of clean secondary energy sources such as hydrogen, large-scale gas storage and conversion using underground aquifer structures has become a research hotspot. One promising technological approach is to directly inject methane into the aquifer, converting it in situ into hydrogen for storage within the formation environment. However, this approach faces a series of severe material and engineering challenges: First, the reforming reaction of methane and water is a strongly endothermic process with an extremely low reaction rate at natural formation temperatures, typically occurring under external heat sources approaching 1000°C. Therefore, there is a lack of highly efficient catalytic fracturing cement capable of long-term stable operation in extreme downhole environments. To achieve economical and efficient in-situ conversion, a highly efficient catalyst must be placed in the underground reaction zone, ensuring sufficient contact and transport between the reactants (methane and water) and the products (syngas). This requires the fracturing cement to possess catalytic activity and a certain degree of permeability.
[0003] Secondly, the catalytic reaction and product environment pose extremely severe coupled challenges to fracturing cement: 1) High temperature: The reaction requires external heating to around 1000℃, far exceeding the tolerance limit of conventional cement slurry; 2) Hydrogen embrittlement: High concentrations and high pressures of hydrogen gas can penetrate the material lattice, causing surface blistering, cracking, and even pulverization; 3) Chemical corrosion: Reaction products such as carbon monoxide and acidic ions in formation fluids can severely corrode the cement matrix. Neither traditional cement nor conventional modified materials are designed to address these coupled failure mechanisms.
[0004] In summary, existing technologies treat fracturing and catalysis as two separate processes, using two single-function materials. Furthermore, current cement slurry systems lack a fracturing cement slurry that can simultaneously achieve in-situ catalytic conversion of methane while possessing ultra-high temperature resistance, resistance to hydrogen embrittlement, corrosion resistance, and a certain degree of permeability. Therefore, there is an urgent need for an innovative material system that integrates the two major functions of "fracture support" and "catalytic conversion," fundamentally simplifying the process and improving the safety, economy, and functionality of aquifer gas storage facilities. Summary of the Invention
[0005] To overcome the aforementioned shortcomings, a self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs is proposed. This slurry integrates the two major functions of "fracture support" and "catalytic conversion," fundamentally simplifying the process and improving the safety, economy, and functionality of aquifer gas storage facilities.
[0006] To achieve the above objectives, the technical solution adopted by this invention is: to provide a self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs. Its components are: 100 parts of G-grade cement, 35-70 parts of water, 3.5 parts of a fluid loss reducer, 2 parts of a retarder, 25-60 parts of a catalytic support functional component, 2-20 parts of an anti-corrosion functional component, 1-10 parts of an anti-hydrogen embrittlement functional component, 5-25 parts of a high-temperature resistant reinforcing component, and 5-25 parts of a permeable pore-forming agent. The catalytic support functional component consists of a rigid porous core and a catalytic active layer supported on its surface. The rigid porous core is made of porous cordierite particles, and the catalytic active layer is made of metallic Ni.
[0007] A further preferred technical solution of the self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is: 100 parts of G-grade cement, 45-60 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35-45 parts of catalytic support functional component, 10-15 parts of anti-corrosion functional component, 4-8 parts of anti-hydrogen embrittlement functional component, 10-20 parts of high-temperature resistant reinforcing component, and 10-20 parts of permeable pore-forming agent.
[0008] A further preferred technical solution of the self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is as follows: the catalytic support functional component is used to achieve the combination of fracture support and catalytic activity, wherein the particle size of the porous cordierite particles is between 20 and 80 mesh, and the loading of the catalytic active layer is 3%-15% of the core mass.
[0009] A further preferred technical solution of the self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is: cerium oxide rare earth oxide is added simultaneously to the catalytic active layer as an additive to improve the catalyst's resistance to carbon deposition and its stability at high temperatures.
[0010] A further preferred embodiment of the self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is that the high-temperature resistant reinforcing component comprises two parts: Microsilica powder: The amount added is 80% of the total mass of this component. It is used to react with the cement hydration product Ca(OH)2 at high temperature to generate a stable mineral phase and improve the high temperature resistance of the material. Basalt fiber: The addition amount is 20% of the total mass of this component, and the fiber length is 3mm-12mm. It is used to bridge microcracks that may occur in the matrix, improve the overall toughness and impact resistance of the material. The silicate basalt fiber has good compatibility with cement and together absorbs the strain energy generated by the thermal expansion of cordierite, preventing the expansion of microcracks or delamination at the interface between aggregate and matrix under high temperature conditions.
[0011] A further preferred technical solution of the retention self-supporting fracturing-catalytic cement slurry for hydrogen production in aquifer reservoirs according to the present invention is: the anti-hydrogen embrittlement functional component is nano-sized vanadium carbide, which is uniformly dispersed in the cement matrix. By forming a bond with hydrogen atoms, it prevents hydrogen atoms from diffusing, aggregating, and combining into destructive hydrogen molecules.
[0012] A further preferred technical solution of the self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is as follows: the anti-corrosion functional component is a layered double hydroxide-magnesium aluminum hydrotalcite, which adsorbs harmful anions in the formation fluid through ion exchange to resist the erosion of carbon monoxide, chloride ions, and sulfate ions. The harmful anions include Cl... - SO4 2- F - ,Br - NO3 - CO3 2- HCO3 - .
[0013] A further preferred technical solution of the self-supporting fracturing-catalytic cement slurry for hydrogen production in aquifer reservoirs according to the present invention is as follows: the pore-forming agent is polylactic acid microspheres, which have the characteristic of slowly degrading and forming pores in the underground environment. After the material is cured, it forms an interconnected micron-sized pore network, providing channels for the diffusion of reactants and products. The degradation products are CO2 / H2O or calcium lactate generated by reaction with the alkaline environment of cement. Calcium lactate exists locally as an inorganic salt filler, which does not pose a risk of corrosion and helps to fill the micropores, ensuring the overall structural safety of the cement.
[0014] A further preferred technical solution of the retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to the present invention is as follows: its preparation steps are as follows: S1, Precast Catalytic Support Aggregate: Completed separately before preparing cement slurry; S1.1, porous cordierite particles with a particle size of 20 to 80 mesh are selected as the rigid core; S1.2, the catalytic active layer is loaded by impregnation method, and a mixed solution of nickel nitrate and cerium nitrate is used for equal-volume impregnation to ensure that the solution fully wets the internal pores of the porous cordierite. S1.3 After impregnation, dry the wet material at around 110℃ to remove moisture; S1.4, The dried material is placed in a muffle furnace and calcined at 500℃-600℃ for 3h-4h in air atmosphere to decompose nitrates into metal oxides NiO and CeO2. S1.5, the precursor is reduced to elemental Ni with higher catalytic activity in a reducing atmosphere of hydrogen-nitrogen mixture at 400℃-600℃ to obtain catalytic support aggregate for later use. S2, Premixing of dry powder materials: In a dry mixing container, the anti-hydrogen embrittlement functional components, anti-corrosion functional components, penetrating pore-forming agents and some high-temperature resistant components are premixed with the cement matrix. Specifically, G-grade cement, nano-sized vanadium carbide, magnesium aluminum hydrotalcite, polylactic acid microspheres and microsilica powder are added in sequence according to the formula ratio. Mechanical stirring is used to fully dry mix the materials to ensure that the nano-sized and micron-sized powder materials are evenly dispersed and mixed. S3, Wet mixing of slurry and fiber dispersion: S3.1 In another mixing container, first add 35-70 parts of water according to the formula, and then add the water loss reducer and retarder in sequence during the stirring process, stirring until they are completely dissolved to form a uniform admixture solution; S3.2, slowly and evenly add the premixed dry powder material from S2 into the solution, keeping stirring to prevent clumping, until all the dry powder has been added and a slurry has been initially formed; S3.3, the pre-weighed basalt fibers are evenly and thinly sprinkled into the slurry in 2-3 batches, with each batch being sprinkled in a time ranging from tens of seconds to several minutes. Continue stirring to ensure that the fibers are completely coated by the slurry and that the monofilaments are dispersed, thus preventing the fibers from tangling into clumps in the slurry. S4, Final mixing of catalytic aggregate and functional slurry: The cordierite catalytic aggregate prepared in S1 is slowly added to the uniform slurry containing fibers prepared in S3. The mixture is stirred slowly to prevent high-speed shearing from damaging the surface structure of the catalytic aggregate or causing the loaded active components to fall off. The mixture is stirred until the catalytic aggregate is evenly distributed in the slurry to form the final pumpable cement slurry.
[0015] Compared with the prior art, the technical solution of the present invention has the following advantages / benefits: 1. This invention proposes an innovative material system that integrates the two major functions of "fracture support" and "catalytic conversion", fundamentally simplifying the process and improving the safety, economy and functionality of aquifer gas storage facilities.
[0016] 2. A multi-layered anti-failure protection system was constructed, which significantly improved the service stability of the material in extreme environments and provided excellent high-temperature resistance, hydrogen embrittlement resistance and corrosion resistance.
[0017] 3. The formation of a continuous permeation network ensures efficient mass transfer between reactants and products, providing a smooth channel for the transport of reactants such as methane and steam, as well as the timely removal of syngas products, thus strongly supporting the continuous and efficient in-situ hydrogen production from methane.
[0018] 4. With the synergistic effect of high temperature resistance, hydrogen embrittlement resistance, corrosion resistance and good structural integrity, the fracturing-catalysis integrated cement slurry prepared by this invention can remain stable in an environment with long-term high temperature, high pressure, hydrogen richness and corrosive fluid coexistence, effectively delaying material aging, cracking and strength decay, thereby significantly extending the overall service life of aquifer hydrogen storage reservoir, reducing later maintenance costs and safety accident risks, and providing a reliable material basis for large-scale underground hydrogen storage and hydrogen production projects. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.
[0020] Figure 1 This is a scanning electron microscope image of the cross-section of cement stone formed from basic cement slurry.
[0021] Figure 2 This is a cross-sectional scanning electron microscope image of cement stone formed from cement slurry containing basic cementitious material G-grade oil well cement, microsilica powder, nano-sized vanadium carbide, magnesium aluminum hydrotalcite, and polylactic acid microspheres prepared based on the present invention.
[0022] Figure 3 This is a cross-sectional scanning electron microscope image of cement stone formed by adding basalt fibers to cement slurry prepared based on the present invention.
[0023] Figure 4 This is a cross-sectional scanning electron microscope image of cement stone formed by fracturing-catalysis integrated cement slurry based on the present invention. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of this invention, not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Therefore, the detailed description of the embodiments of this invention provided below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention.
[0025] Example 1:
[0026] like Figure 1As shown, a self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir comprises: 100 parts of G-grade cement, 35-70 parts of water, 3.5 parts of a fluid loss reducer, 2 parts of a retarder, 25-60 parts of a catalytic support functional component, 2-20 parts of a corrosion-resistant functional component, 1-10 parts of a hydrogen embrittlement-resistant functional component, 5-25 parts of a high-temperature resistant reinforcing component, and 5-25 parts of a permeable pore-forming agent.
[0027] The catalytic support functional component consists of a rigid porous core and a catalytically active layer supported on its surface, which is used to achieve the combination of slit support and catalytic activity.
[0028] The rigid porous core is made of porous cordierite particles (2MgO·2Al2O3·5SiO2), with a particle size between 20 and 80 mesh. The catalytic active layer is made of elemental Ni metal, with a loading of 3%-15% of the core mass. Cerium oxide (CeO2) rare earth oxide is added to the catalytic active layer as an additive to improve the catalyst's resistance to carbon deposition and its stability at high temperatures.
[0029] The high-temperature resistant reinforcing component consists of two parts: Microsilica powder: The amount added is 80% of the total mass of this component. It is used to react with the cement hydration product Ca(OH)2 at high temperature to generate stable mineral phases such as calcium silicate, thereby improving the high temperature resistance of the material. Basalt fiber: The addition amount is 20% of the total mass of this component, and the fiber length is 3mm-12mm. It is used to bridge microcracks that may occur in the matrix, improve the overall toughness and impact resistance of the material. The silicate basalt fiber has good compatibility with cement and together absorbs the strain energy generated by the thermal expansion of cordierite, preventing the expansion of microcracks or delamination at the interface between aggregate and matrix under high temperature conditions.
[0030] The anti-hydrogen embrittlement functional component is nano-sized vanadium carbide, which is uniformly dispersed in the cement matrix. By forming a bond with hydrogen atoms, it prevents hydrogen atoms from diffusing, aggregating, and combining into destructive hydrogen molecules.
[0031] The anti-corrosion functional component is a layered double hydroxide-magnesium aluminum hydrotalcite (Mg-Al LDHs), which adsorbs harmful anions Cl in formation fluids through ion exchange. - SO4 2- These are used to resist the corrosion of carbon monoxide, chloride ions, and sulfate ions.
[0032] The penetrating pore-forming agent is polylactic acid (PLA) microspheres, which slowly degrade in the underground environment to form pores. After the material is cured, it forms an interconnected micron-sized network of pores, providing channels for the diffusion of reactants and products. The degradation products are CO2 / H2O or calcium lactate generated by reacting with the alkaline environment of cement. Calcium lactate exists locally as an inorganic salt filler, which does not pose a risk of corrosion and helps to fill the micropores, ensuring the overall structural safety.
[0033] Example 2:
[0034] Based on Example 1, the composition is further limited to: 100 parts of Grade G cement, 45-60 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35-45 parts of catalytic support functional component, 10-15 parts of anti-corrosion functional component, 4-8 parts of anti-hydrogen embrittlement functional component, 10-20 parts of high temperature resistant reinforcing component, and 10-20 parts of penetrating pore-forming agent.
[0035] Example 3:
[0036] Take 100 parts of Grade G cement, 35 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 25 parts of catalyst supporting functional component, 2 parts of anti-corrosion functional component, 1 part of anti-hydrogen embrittlement functional component, 5 parts of high temperature resistant reinforcing component, and 5 parts of penetrating pore-forming agent. The test results of various properties are shown in the table below.
[0037] Table 1 Performance test results of the formulation in Example 3
[0038] Example 4:
[0039] The following table shows the test results of various properties of 100 parts of Grade G cement, 45 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35 parts of catalytic support functional component, 10 parts of anti-corrosion functional component, 4 parts of anti-hydrogen embrittlement functional component, 10 parts of high temperature resistant reinforcing component, and 10 parts of penetrating pore-forming agent.
[0040] Table 2 Performance test results of the formulation in Example 4
[0041] Example 5:
[0042] The following table shows the test results of various properties of 100 parts of Grade G cement, 60 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 45 parts of catalytic support functional component, 15 parts of anti-corrosion functional component, 8 parts of anti-hydrogen embrittlement functional component, 20 parts of high temperature resistant reinforcing component, and 20 parts of penetrating pore-forming agent.
[0043] Table 3 Performance test results of the formulation in Example 5
[0044] Example 6:
[0045] The following table shows the test results of various properties of 100 parts of Grade G cement, 70 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 60 parts of catalytic support functional component, 20 parts of anti-corrosion functional component, 10 parts of anti-hydrogen embrittlement functional component, 25 parts of high temperature resistant reinforcing component, and 25 parts of penetrating pore-forming agent.
[0046] Table 4 Performance test results of the formulation in Example 6
[0047] Example 7:
[0048] The following table shows the test results of various properties of 100 parts of Grade G cement, 50 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 45 parts of catalytic support functional component, 11 parts of anti-corrosion functional component, 5 parts of anti-hydrogen embrittlement functional component, 15 parts of high temperature resistant reinforcing component, and 15 parts of penetrating pore-forming agent.
[0049] Table 5 Performance test results of the formulation in Example 7
[0050] Example 8:
[0051] The following table shows the test results of various properties of 100 parts of Grade G cement, 45 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 45 parts of catalytic support functional component, 10 parts of anti-corrosion functional component, 4 parts of anti-hydrogen embrittlement functional component, 10 parts of high temperature resistant reinforcing component, and 10 parts of penetrating pore-forming agent.
[0052] Table 6 Performance test results of the formulation in Example 8
[0053] Example 9:
[0054] The following table shows the test results of various properties of 100 parts of Grade G cement, 45 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35 parts of catalytic support functional component, 11 parts of anti-corrosion functional component, 4 parts of anti-hydrogen embrittlement functional component, 10 parts of high temperature resistant reinforcing component, and 10 parts of penetrating pore-forming agent.
[0055] Table 7 Performance test results of the formulation in Example 9
[0056] Example 10: The following table shows the test results of various properties of 100 parts of Grade G cement, 45 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35 parts of catalytic support functional component, 10 parts of anti-corrosion functional component, 5 parts of anti-hydrogen embrittlement functional component, 10 parts of high temperature resistant reinforcing component, and 10 parts of penetrating pore-forming agent.
[0057] Table 8 Performance test results of the formulation in Example 10
[0058] Example 11: The following table shows the test results of various properties of 100 parts of Grade G cement, 45 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35 parts of catalytic support functional component, 10 parts of anti-corrosion functional component, 4 parts of anti-hydrogen embrittlement functional component, 15 parts of high temperature resistant reinforcing component, and 15 parts of penetrating pore-forming agent.
[0059] Table 9 Performance test results of the formulation in Example 11
[0060] Example 12: 100 parts of G-grade oil well cement, 45 parts of water, 3.5 parts of fluid loss reducer (AMPS copolymer), 2.0 parts of retarder (lignin sulfonate), 40 parts of catalyst support functional component (specifically, porous cordierite particles loaded with 12% Ni and 3% CeO2, with a particle size of 40-60 mesh), 17.5 parts of high-temperature resistant reinforcing component (including 15 parts of microsilica powder and 2.5 parts of basalt fiber (6 mm in length), 3 parts of hydrogen embrittlement resistant functional component (nano-sized vanadium carbide (VC) powder), 5 parts of corrosion resistant functional component (magnesium aluminum hydrotalcite (Mg-AlLDHs, Mg / Al molar ratio = 2:1)), and 10 parts of permeation pore-forming agent (polylactic acid (PLA) microspheres, with an average particle size of 150 μm) were taken. The test results of various properties are shown in the table below.
[0061] Table 10 Performance test results of the formulation in Example 12
[0062] Example 13: A type of retained self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs, the preparation steps of which are as follows: S1, Precast Catalytic Support Aggregate: Completed separately before preparing cement slurry. S1.1, porous cordierite particles with a particle size of 20 to 80 mesh are selected as the rigid core; S1.2, the catalytic active layer is loaded by impregnation method, and a mixed solution of nickel nitrate and cerium nitrate is used for equal-volume impregnation to ensure that the solution fully wets the internal pores of the porous cordierite. S1.3 After impregnation, dry the wet material at around 110℃ to remove moisture; S1.4, The dried material is placed in a muffle furnace and calcined at 500℃-600℃ for 3h-4h in air atmosphere to decompose nitrates into metal oxides NiO and CeO2. S1.5, the precursor is reduced to elemental Ni with higher catalytic activity in a reducing atmosphere of hydrogen-nitrogen mixture (such as 5% H2 + 95% N2 (volume fraction)) at 400℃-600℃ to obtain catalytic support aggregate for later use. S2, Premixing of dry powder materials: In a dry mixing container, the anti-hydrogen embrittlement functional components, anti-corrosion functional components, penetrating pore-forming agents and some high-temperature resistant components are premixed with the cement matrix. Specifically, the basic cementitious material G-grade cement, nano-sized vanadium carbide, magnesium aluminum hydrotalcite (Mg-Al LDHs), polylactic acid (PLA) microspheres and microsilica powder are added in sequence according to the formula ratio. Mechanical stirring is used to fully dry mix the materials to ensure that the nano-sized and micron-sized powder materials are uniformly dispersed and mixed. S3, Wet mixing and fiber dispersion of slurry: S3.1, In another mixing vessel, first add 35-70 parts of water according to the formula, and then add the water loss reducer and retarder in sequence during the mixing process, stirring until they are completely dissolved to form a uniform admixture solution; S3.2, slowly and evenly add the premixed dry powder material from S2 into the solution, keeping stirring to prevent clumping, until all the dry powder has been added and a slurry has been initially formed; S3.3, the pre-weighed basalt fibers (3-12 mm in length) are evenly and thinly sprinkled into the slurry in 2-3 batches. Each batch is sprinkled in a time ranging from tens of seconds to several minutes. Continue stirring to ensure that the fibers are completely coated by the slurry and that the monofilaments are dispersed, so as to avoid the fibers from tangling into clumps in the slurry. S4, Final mixing of catalytic aggregate and functional slurry: The cordierite catalytic aggregate prepared in S1 is slowly added to the homogeneous slurry containing fibers obtained in S3. Slow stirring is used to prevent high-speed shearing from damaging the surface structure of the catalytic aggregate or causing the loaded active components to detach. Stirring continues until the catalytic aggregate is evenly distributed in the slurry, forming the final pumpable cement slurry. This preparation method is applicable to all embodiments and comparative examples in this invention.
[0063] Comparative Example 1: A basic cement slurry containing only Grade G cement, water, and conventional admixtures (water loss reducer, retarder).
[0064] 100 parts of Grade G oil well cement, 45 parts of water, 3.5 parts of fluid loss reducer (AMPS copolymer), and 2.0 parts of retarder (lignin sulfonate).
[0065] Comparative Example 2: It contains Grade G cement, water, water loss reducer, retarder, quartz sand (to replace catalytic aggregate), high-temperature resistant reinforcing components and permeable pore-forming agent, but does not contain catalytic components, hydrogen embrittlement resistant components, or corrosion resistant components.
[0066] 100 parts of Grade G oil well cement, 45 parts of water, 3.5 parts of fluid loss control agent (AMPS copolymer), 2.0 parts of retarder (lignin sulfonate), 40 parts of quartz sand, 17.5 parts of high temperature resistant reinforcing component (including 15 parts of microsilica powder and 2.5 parts of basalt fiber (6 mm in length)) and 10 parts of permeable pore-forming agent (polylactic acid (PLA) microspheres with an average particle size of 150 μm).
[0067] The material of Example 9 of the present invention was subjected to performance tests and comparative tests in application simulations compared with the materials of Comparative Examples 1 and 2: High-temperature compressive strength: The prepared cement slurry was injected into a mold and cured under simulated formation pressure until initial setting, then heat-treated in a muffle furnace at 1000℃ for 24 hours. After cooling, its compressive strength was tested, and its strength retention rate was expected to be significantly higher than that of ordinary cement stone without the addition of high-temperature resistant components.
[0068] Catalytic performance evaluation: The cured material was crushed into particles and placed in a fixed-bed reactor. A mixture of CH4 and H2O(g) was introduced, and the methane conversion, carbon monoxide, and hydrogen yields were evaluated at 1000℃ and a certain pressure. The Ni / CeO2-cordierite aggregate is expected to exhibit high activity and resistance to carbon deposition.
[0069] Hydrogen embrittlement resistance test: After the sample is placed in a high-pressure hydrogen environment (such as 10 MPa H2, 100℃) for a period of time, mechanical property tests or microstructure observations are performed to verify the inhibitory effect of nano-sized vanadium carbide on hydrogen-induced cracking.
[0070] Permeability test: The gas permeability of the solidified and PLA-degraded sample was measured using a gas permeability meter to verify that it possesses the interconnected pores required for gas diffusion. The test results are shown in Table 11.
[0071] Table 11 Comparison Test Results
[0072] In this invention, unless otherwise explicitly specified and limited, the terms "dispersion," "loading," "coating," and "bonding," etc., should be interpreted broadly. For example, they can refer to physical dispersion, chemical bonding, or in-situ coating; they can refer to surface loading or lattice doping; they can refer to direct bonding or indirect action through ligands; and they can refer to the uniform distribution of active components in the cement matrix or the synergistic effect of catalytic active sites. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0073] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A type of retained self-supporting fracturing-catalytic cement slurry for hydrogen production from aquifer reservoirs, characterized in that, The product comprises the following components in parts by weight: 100 parts of Grade G cement, 35-70 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 25-60 parts of catalytic support functional component, 2-20 parts of corrosion-resistant functional component, 1-10 parts of hydrogen embrittlement-resistant functional component, 5-25 parts of high-temperature resistant reinforcing component, and 5-25 parts of permeable pore-forming agent. The catalytic support functional component consists of a rigid porous core and a catalytic active layer supported on its surface. The rigid porous core is made of porous cordierite particles, and the catalytic active layer is made of metallic Ni.
2. The retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1, characterized in that, Its components are: 100 parts of G-grade cement, 45-60 parts of water, 3.5 parts of water loss reducing agent, 2 parts of retarder, 35-45 parts of catalytic support functional component, 10-15 parts of anti-corrosion functional component, 4-8 parts of anti-hydrogen embrittlement functional component, 10-20 parts of high temperature resistant reinforcing component, and 10-20 parts of penetrating pore-forming agent.
3. The retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1, characterized in that, The catalytic support functional component is used to achieve the combination of crack support and catalytic activity, wherein the particle size of the porous cordierite particles is between 20 and 80 mesh, and the loading of the catalytic active layer is 3%-15% of the core mass.
4. The retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 3, characterized in that, Cerium oxide rare earth oxides are added to the catalytic active layer as an additive to improve the catalyst's resistance to carbon deposition and its stability at high temperatures.
5. A retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1 or 2, characterized in that, The high-temperature resistant reinforcing component consists of two parts: Microsilica powder: The amount added is 80% of the total mass of this component. It is used to react with the cement hydration product Ca(OH)2 at high temperature to generate a stable mineral phase and improve the high temperature resistance of the material. Basalt fiber: The addition amount is 20% of the total mass of this component, and the fiber length is 3mm-12mm. It is used to bridge microcracks that may occur in the matrix, improve the overall toughness and impact resistance of the material. The silicate basalt fiber has good compatibility with cement and together absorbs the strain energy generated by the thermal expansion of cordierite, preventing the expansion of microcracks or delamination at the interface between aggregate and matrix under high temperature conditions.
6. A retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1 or 2, characterized in that, The anti-hydrogen embrittlement functional component is nano-sized vanadium carbide, which is uniformly dispersed in the cement matrix. By forming a bond with hydrogen atoms, it prevents hydrogen atoms from diffusing, aggregating, and combining into destructive hydrogen molecules.
7. A retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1 or 2, characterized in that, The anti-corrosion functional component is a layered double hydroxide-magnesium aluminum hydrotalcite, which adsorbs harmful anions in the formation fluid through ion exchange, and is used to resist corrosion of carbon monoxide, chloride ions, sulfate ions, and harmful anions including Cl - , SO4 2- , F - , Br - , NO3 - , CO3 2- , HCO3 - .
8. A retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1 or 2, characterized in that, The penetrating pore-forming agent is polylactic acid microspheres, which have the characteristic of slowly degrading and forming pores in underground environments. After the material is cured, it forms an interconnected micron-sized pore network, providing channels for the diffusion of reactants and products. The degradation products are CO2 / H2O or calcium lactate generated by reacting with the alkaline environment of cement. Calcium lactate exists locally as an inorganic salt filler, which does not pose a risk of corrosion and helps to fill the micropores, ensuring the overall structural safety of the cement.
9. A retained self-supporting fracturing-catalytic cement slurry for hydrogen production from an aquifer reservoir according to claim 1 or 2, characterized in that, The preparation steps are as follows: S1, Precast Catalytic Support Aggregate: Completed separately before preparing cement slurry; S1.1, porous cordierite particles with a particle size of 20 to 80 mesh are selected as the rigid core; S1.2, the catalytic active layer is loaded by impregnation method, and a mixed solution of nickel nitrate and cerium nitrate is used for impregnation in equal volume to ensure that the solution fully wets the internal pores of porous cordierite; S1.3 After impregnation, dry the wet material at around 110℃ to remove moisture; S1.4, The dried material is placed in a muffle furnace and calcined at 500℃-600℃ for 3h-4h in air atmosphere to decompose nitrates into metal oxides NiO and CeO2. S1.5, the precursor is reduced to elemental Ni with higher catalytic activity in a reducing atmosphere of hydrogen-nitrogen mixture at 400℃-600℃ to obtain catalytic support aggregate for later use. S2, Premixing of dry powder materials: In a dry mixing container, the anti-hydrogen embrittlement functional components, anti-corrosion functional components, penetrating pore-forming agents and some high-temperature resistant components are premixed with the cement matrix. Specifically, G-grade cement, nano-sized vanadium carbide, magnesium aluminum hydrotalcite, polylactic acid microspheres and microsilica powder are added in sequence according to the formula ratio. Mechanical stirring is used to fully dry mix the materials to ensure that the nano-sized and micron-sized powder materials are evenly dispersed and mixed. S3, Wet mixing of slurry and fiber dispersion: S3.1 In another mixing container, first add 35-70 parts of water according to the formula, and then add the water loss reducer and retarder in sequence during the stirring process, stirring until they are completely dissolved to form a uniform admixture solution; S3.2, slowly and evenly add the premixed dry powder material from S2 into the solution, keeping stirring to prevent clumping, until all the dry powder has been added and a slurry has been initially formed; S3.3, the pre-weighed basalt fibers are evenly and thinly sprinkled into the slurry in 2-3 batches, with each batch being sprinkled in a time ranging from tens of seconds to several minutes. Continue stirring to ensure that the fibers are completely coated by the slurry and that the monofilaments are dispersed, thus preventing the fibers from tangling into clumps in the slurry. S4, Final mixing of catalytic aggregate and functional slurry: The cordierite catalytic aggregate prepared in S1 is slowly added to the uniform slurry containing fibers prepared in S3. The mixture is stirred slowly to prevent high-speed shearing from damaging the surface structure of the catalytic aggregate or causing the loaded active components to fall off. The mixture is stirred until the catalytic aggregate is evenly distributed in the slurry to form the final pumpable cement slurry.