Bulk catalytic proppant and its preparation method and application

Abstract

The present invention relates to the field of functionalized proppants for shale fracturing, and specifically to a bulk catalytic proppant comprising: a modified clay bearing SO3H groups and an additive; wherein the weight ratio of clay to SO3H groups in the modified clay bearing SO3H groups is 5-20:1. The bulk catalytic proppant of the present invention has the properties of supporting shale microfractures and catalyzing hydrocarbon generation and conversion in situ, significantly improving the utilization rate of oil shale resources. The bulk proppant has advantages such as high acid content, high acid strength, controllable particle size, and ease of large-scale preparation. It can improve the oil recovery rate and quality of oil shale.

Description

Technical Field

[0001] The present invention relates to the field of shale fracturing functionalized proppants, and in particular to a bulk catalytic proppant and a preparation method and application thereof. Background Art

[0002] Currently, the three most common types of proppants are quartz sand, artificial ceramsite, and resin-coated sand, which account for over 95% of the total usable volume. Among them, artificial ceramsite is widely used in medium- to deep-wells due to its good sphericity, high strength, corrosion resistance, and excellent conductivity.

[0003] With the development of oil shale hydraulic fracturing technology, higher requirements are being placed on the strength, surface properties, and conductivity of proppants. In particular, there is a strong demand for proppants with catalytic activity centers. Catalytic proppants must not only have the performance of ceramsite proppants, but also possess catalytic activity centers that can convert organic matter such as kerogen in the reservoir into crude oil.

[0004] my country's continental shales are characterized by high clay content in their formations, but existing catalytic proppants suffer from poor organic matter conversion activity and low conversion efficiency. Therefore, there is a need to develop efficient bulk catalytic functionalized proppants suitable for high-clay shale reservoirs. This could enable an integrated technology for oil shale fracture propping and in-situ catalytic conversion of organic matter, improving oil shale recovery and oil quality. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of the existing catalytic proppant in the prior art, such as insufficient acid content or weak acid strength, poor conversion activity of organic matter to hydrocarbons, low conversion efficiency, etc., and to provide a bulk catalytic proppant and its preparation method and application.

[0006] To achieve the above objectives, the first aspect of the present invention provides a bulk catalytic proppant, comprising: modified clay with SO3H groups and an additive; wherein, in the modified clay with SO3H groups, the weight ratio of clay to SO3H groups is 5-20:1.

[0007] A second aspect of the present invention provides a method for preparing a bulk catalytic proppant, comprising the following steps:

[0008] (1) After the clay is activated with acid, a thiol-forming agent is added to perform wet ball milling grafting;

[0009] (2) reacting the product obtained in step (1) with an oxidant to obtain a modified clay having a SO3H group;

[0010] (3) The modified clay with SO3H groups and the auxiliary agent are mixed, and the bulk catalytic support is obtained by granulation and calcination.

[0011] A third aspect of the present invention provides an application of the bulk catalytic proppant in shale fracturing micro-fracture support.

[0012] Through the above technical solution, the bulk catalytic proppant of the present invention has the following technical advantages:

[0013] (1) The bulk catalytic proppant of the present invention has the performance of supporting shale micro-fractures and in-situ catalytic hydrocarbon conversion, which significantly improves the utilization rate of oil shale resources.

[0014] (2) The bulk catalytic proppant of the present invention has the advantages of large acid content, high acid strength, controllable particle size, and easy large-scale preparation, which can improve the oil recovery rate of oil shale and improve the quality of produced oil.

[0015] (3) The preparation method of the bulk catalytic support agent of the present invention can avoid the step of refluxing the organic solvent, and the process is environmentally friendly.

[0016] (4) The method for preparing the bulk catalytic proppant of the present invention can control the acid content of the proppant according to the processing requirements, thereby regulating the optimal catalytic proppant dosage for oil shale hydrocarbon generation conversion.

[0017] (5) The fine particle proppant with a particle size of 0.1-2 mm prepared by the present invention can ensure effective support for fracture micro-cracks and narrow cracks.

[0018] (6) The bulk catalytic support used in the present invention has high strength and low acid solubility, meeting national standards.

[0019] (7) The process of the present invention is simple, no waste acid is discharged, and a large-scale oil shale catalytic proppant production line can be quickly formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a scanning electron microscope image of the catalytic support agent of Example 1 of the present invention;

[0021] Figure 2 is a scanning electron microscope image of the catalytic support agent of Example 2 of the present invention;

[0022] Figure 3 is a scanning electron microscope image of the catalytic support agent of Example 3 of the present invention;

[0023] Figure 4 This is a scanning electron microscope image of the catalytic support agent of Example 4 of the present invention. DETAILED DESCRIPTION

[0024] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0025] A first aspect of the present invention provides a bulk catalytic proppant, wherein the catalytic proppant comprises: modified clay with SO3H groups and an additive; wherein, in the modified clay with SO3H groups, the weight ratio of clay to SO3H groups is 5-20:1.

[0026] The clay carries SO3H groups, which generate sulfur-doped carbon quantum dots in the proppant pores, maintaining the acid properties while having high hydrothermal stability. This is the unique advantage of the prepared catalytic proppant. This makes the bulk catalytic proppant have high acid density, controllable acid amount, and good particle size controllability. At the same time, the present application controls the weight ratio of the clay and SO3H groups to 5-20:1, so that the modified clay with SO3H groups added to the catalytic proppant has the characteristics of large acid amount and high acid strength. It can effectively solve the problem of poor in-situ conversion and hydrocarbon generation performance of resources such as medium and low maturity shale oil and oil shale due to small acid amount and low acid strength, and overcome the defect of insufficient support of ceramsite proppants for narrow gaps and tiny gaps.

[0027] In the present invention, modified clay with SO3H groups, i.e., a sulfonic acid group-modified acidic catalyst, is added to a bulk catalytic proppant, which can not only catalyze hydrocarbon conversion in situ during the fracturing process, but also act as a proppant together with additives such as kaolin, bauxite, and dolomite to support shale micro-fractures during the fracturing process. At the same time, the catalytic proppant of the present invention has the characteristics of large acid content and high acid strength, which can effectively solve the problem of poor in-situ hydrocarbon conversion performance of resources such as medium- and low-maturity shale oil and oil shale due to small acid content and low acid strength, and overcome the defect of insufficient support of ceramsite proppants for narrow cracks and tiny gaps.

[0028] In some specific embodiments of the present invention, the auxiliary agent includes an additive and a structural auxiliary agent, wherein the additive is selected from one or more of kaolin, bauxite, and dolomite. Adding a certain amount of the above additive to the proppant can improve the strength of the proppant. The structural auxiliary agent is selected from one or more of citric acid, cellulose, and starch. Adding a certain amount of the above structural auxiliary agent to the proppant plays a bonding and pore-forming role, increases the surface area of ​​the proppant, and improves the catalytic and support performance. Among the auxiliary agents, the structural auxiliary agent is 5-15wt%.

[0029] In some specific embodiments of the present invention, the weight ratio of the modified clay with SO3H groups to the auxiliary agent is 1-10:1. Within this weight ratio range, the prepared proppant has a high acid density.

[0030] In some specific embodiments of the present invention, the particle size of the proppant is 0.1-2 mm, and the particle size distribution can be adjusted according to production requirements, so that the prepared proppant has adjustable acid content and particle size.

[0031] In some specific embodiments of the present invention, the modified clay with SO3H groups is obtained by sequentially subjecting clay to acid activation, thiolization, wet ball milling grafting, and oxidation. By adding the modified clay with SO3H groups, i.e., a sulfonic acid-modified acidic catalyst, to a bulk catalytic proppant, the modified clay can not only catalyze hydrocarbon conversion in situ during the fracturing process, but also function as a proppant in conjunction with additives such as kaolin, bauxite, and dolomite to support shale microfractures during the fracturing process. Furthermore, the catalytic proppant of the present invention has high acid content and high acid strength, effectively resolving the problem of poor in-situ hydrocarbon conversion performance for resources such as medium- and low-maturity shale oil and oil shale due to low acid content and low acid strength, while also overcoming the drawback of ceramsite proppants that often provide insufficient support for narrow and microscopic cracks.

[0032] In some specific embodiments of the present invention, the weight ratio of the modified clay with SO3H groups to the auxiliary agent is controlled to be 1-10:1, and the acid content is adjusted according to the amount of thiol grafting so that the acid content of the proppant is greater than 1 mmol / g.

[0033] In some specific embodiments of the present invention, the acid content of the proppant is determined by an alkali adsorption method.

[0034] A second aspect of the present invention provides a method for preparing a bulk catalytic proppant, comprising the following steps:

[0035] (1) After the clay is activated with acid, a thiol-forming agent is added and wet ball milling grafting is performed;

[0036] (2) reacting the product obtained in step (1) with an oxidant to obtain a modified clay having a SO3H group;

[0037] (3) The modified clay with SO3H groups and the auxiliary agent are mixed, and the bulk catalytic support is obtained by granulation and calcination.

[0038] In some specific embodiments of the present invention, in step (1), the acid is selected from one or more of hydrochloric acid, nitric acid, and sulfuric acid.

[0039] In some specific embodiments of the present invention, the clay is selected from attapulgite clay and / or zeolite, wherein the zeolite is preferably clinoptilolite.

[0040] In some specific embodiments of the present invention, in step (1), the clay is activated with acid, stirred at 40° C. for a period of time, filtered, and dried.

[0041] In some specific embodiments of the present invention, the thiol-forming agent is selected from one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxysilane.

[0042] In some specific embodiments of the present invention, in step (1), after adding the thiol-forming agent, a small amount of water is added, and wet ball milling grafting is performed using a ball mill, followed by washing with distilled water and drying.

[0043] In some specific embodiments of the present invention, the oxidant is selected from one or more of hydrogen peroxide, nitric acid, sodium hypochlorite, and peracetic acid.

[0044] In some specific embodiments of the present invention, the auxiliary agent is selected from one or more of kaolin, bauxite, and dolomite.

[0045] In some embodiments of the present invention, the proppant additive further comprises a structural additive selected from one or more of citric acid, cellulose, and starch. Adding a certain amount of these structural additives to the proppant serves to bind and create pores, increasing the proppant's surface area and enhancing its catalytic and support properties. The structural additive comprises 5-15 wt% of the additive.

[0046] In some specific embodiments of the present invention, in step (2), after reacting with the oxidant, the mixture is washed with distilled water and dried to obtain modified clay with SO3H groups.

[0047] In some specific embodiments of the present invention, the modified clay with SO3H groups and the additives need to be ground before mixing.

[0048] In some specific embodiments of the present invention, the weight ratio of the clay to the auxiliary agent is 1-10:1.

[0049] In some specific embodiments of the present invention, the mass ratio of the clay to the acid, the thiol-forming agent, and the oxidant is 1:3-6:0.3-3:1-9.

[0050] In some specific embodiments of the present invention, in step (3), the calcination temperature is 750-1100° C., and the calcination time is 0.5-3 h.

[0051] The third aspect of the present invention provides an application of the bulk catalytic proppant in shale fracturing micro-fracture support.

[0052] The catalytic proppant prepared by the present invention is used for in-situ catalytic conversion of oil shale. In a 100 mL batch reactor in the laboratory, oil shale, water and the catalytic proppant are added, the temperature is raised to 280-350° C. at a certain heating rate, maintained for 4 hours, the reactor is cooled to room temperature, and the product is taken out for product property analysis.

[0053] The present invention will be described in detail below through examples.

[0054] In the following examples and comparative examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents and instruments used, if no manufacturer is specified, are commercially available conventional products.

[0055] Example 1

[0056] 2 g of attapulgite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40 ° C for a period of time, filtered and dried, and the acidified attapulgite, 2.6 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water and 50 g of agate medium balls were added to a 50 mL resin jar, and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, it was washed with distilled water three times to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85 ° C for 12 hours to obtain mercapto-modified attapulgite; the prepared mercapto-modified attapulgite was added to 50 mL (15%) of an aqueous solution of hydrogen peroxide, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85 ° C to obtain modified clay with SO3H groups.

[0057] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (20wt% kaolin, 65wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0058] In the obtained proppant, the weight ratio of clay to SO3H group is 5:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 1.496 mmol / g.

[0059] Example 2

[0060] 2 g of attapulgite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40 ° C for a period of time, filtered and dried, and attapulgite, 1.6 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water and 50 g of agate medium balls were added to a 50 mL resin jar and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, it was washed with distilled water three times to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85 ° C for 12 hours to obtain mercapto-modified attapulgite; the prepared mercapto-modified attapulgite was added to 30 mL (15%) of an aqueous solution of hydrogen peroxide, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85 ° C to obtain modified clay with SO3H groups.

[0061] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (30wt% kaolin, 55wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0062] In the obtained proppant, the weight ratio of clay to SO3H group is 8:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 1.253 mmol / g.

[0063] Example 3

[0064] 2 g of clinoptilolite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40° C. for a period of time, filtered, and dried. The acidified clinoptilolite, 3 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water, and 50 g of agate medium balls were added to a 50 mL resin jar and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, the mixture was washed three times with distilled water to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85° C. for 12 hours to obtain mercapto-modified clinoptilolite. The prepared mercapto-modified clinoptilolite was added to 25 mL of a 15% hydrogen peroxide aqueous solution, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85° C. to obtain modified clay with SO3H groups.

[0065] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (35wt% kaolin, 50wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0066] In the obtained proppant, the weight ratio of clay to SO3H group is 10:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 1.187 mmol / g.

[0067] Example 4

[0068] 2 g of clinoptilolite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40° C. for a period of time, filtered, and dried. The acidified clinoptilolite, 0.65 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water, and 50 g of agate medium balls were added to a 50 mL resin jar and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, the mixture was washed three times with distilled water to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85° C. for 12 hours to obtain mercapto-modified clinoptilolite. The prepared mercapto-modified clinoptilolite was added to 20 mL of a 15% hydrogen peroxide aqueous solution, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85° C. to obtain modified clay with SO3H groups.

[0069] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (40wt% kaolin, 45wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0070] In the obtained proppant, the weight ratio of clay to SO3H group is 20:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 1.046 mmol / g.

[0071] Comparative Example 1

[0072] 2 g of attapulgite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40 ° C for a period of time, filtered and dried, and the acidified attapulgite, 4.5 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water and 50 g of agate medium balls were added to a 50 mL resin jar, and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, it was washed with distilled water three times to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85 ° C for 12 hours to obtain mercapto-modified attapulgite; the prepared mercapto-modified attapulgite was added to 80 mL (15%) of an aqueous solution of hydrogen peroxide, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85 ° C to obtain modified clay with SO3H groups.

[0073] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (20wt% kaolin, 65wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0074] In the obtained proppant, the weight ratio of clay to SO3H group is 3:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 1.539 mmol / g.

[0075] Comparative Example 2

[0076] 2 g of clinoptilolite was acidified with 20 mL of 6 mol / L hydrochloric acid, stirred at 40° C. for a period of time, filtered, and dried. The acidified clinoptilolite, 0.43 g of 3-mercaptopropyltrimethoxysilane, 10 mL of water, and 50 g of agate medium balls were added to a 50 mL resin jar and ball milled at 300 rpm using a planetary ball mill for 2.5 hours. After the reaction, the mixture was washed three times with distilled water to remove unreacted 3-mercaptopropyltrimethoxysilane, and then dried at 85° C. for 12 hours to obtain mercapto-modified clinoptilolite. The prepared mercapto-modified clinoptilolite was added to 15 mL of a 15% hydrogen peroxide aqueous solution, stirred at room temperature for 12 hours, then washed with distilled water, and dried at 85° C. to obtain modified clay with SO3H groups.

[0077] 40g of the prepared modified clay with SO3H groups was ground separately with 10g of additives (40wt% kaolin, 45wt% bauxite, 5wt% dolomite, 9wt% cellulose, and 1wt% citric acid) to obtain a mixture of kaolin powder, bauxite powder, dolomite powder, and modified clay powder with SO3H groups. After the powders were uniformly mixed, they were granulated in a spray granulator. The pellets were dried in an oven. The dried pellets were subjected to programmed temperature calcination, increasing the temperature to 800°C at 50°C / min for 90min, then increasing the temperature to 1100°C at 50°C / min for 60min.

[0078] In the obtained proppant, the weight ratio of clay to SO3H group is 30:1, the weight ratio of the modified clay with SO3H group to the auxiliary agent is 4:1, and the acid content of the proppant is 0.875 mmol / g.

[0079] The catalytic supports prepared in Examples 1-4 were scanned by electron microscope, and the results were as follows: Figure 1-4 As shown, it can be seen that the prepared proppant has high sphericity and a pore structure.

[0080] The prepared catalytic proppant was used to evaluate the catalytic conversion performance of oil shale in a laboratory batch reactor.

[0081] Test Example 1:

[0082] 8 g of shale powder, 2 g of the catalytic proppant prepared in Example 1, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0083] Test Example 2:

[0084] 8 g of shale powder, 2 g of the catalytic proppant prepared in Example 2, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0085] Test Example 3:

[0086] 8 g of shale powder, 2 g of the catalytic proppant prepared in Example 3, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0087] Test Example 4:

[0088] 8 g of shale powder, 2 g of the catalytic proppant prepared in Example 4, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0089] Test Example 5:

[0090] 8 g of shale powder, 2 g of the catalytic proppant prepared in Comparative Example 1, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0091] Test Example 6:

[0092] 8 g of shale powder, 2 g of the catalytic proppant prepared in Comparative Example 2, and 20 mL of water were added to a reactor and reacted at 300° C. for 4 h.

[0093] Test Example 7:

[0094] The comparative example is the thermal conversion of pure oil shale without any catalyst. 10 g of shale powder and 20 mL of water were added to a reactor and reacted at 300°C for 4 h.

[0095] The oil and gas production from pyrolysis of oil shale after adding different catalytic proppants was evaluated by measuring the product oil yield. The results are shown in Table 1.

[0096] Table 1

[0097] project Residue (%) Oil yield (%) Gas production rate (%) Test Example 1 20.8 32.8 46.4 Test Example 2 19.5 31.5 49.5 Test Example 3 20.1 37.8 42.1 Test Example 4 18.3 33.9 47.8 Test Example 5 20.3 33.2 46.5 Test Example 6 24.7 29.8 45.5 Test Example 7 26.2 28.4 45.4

[0098] The results in Table 1 show that, compared with thermal conversion of oil shale without a catalytic proppant, the addition of a catalytic proppant significantly increases the oil yield and reduces the residue rate, indicating that the addition of a catalytic proppant increases oil production. When the weight ratio of clay to SO3H groups in the catalytic proppant is less than 5:1, the catalytic activity of the catalytic proppant is not significantly improved, and manufacturing costs increase. When the weight ratio of clay to SO3H groups in the catalytic proppant is greater than 20:1, the catalytic activity of the catalyst is significantly weakened. Therefore, a weight ratio of clay to SO3H groups in the catalytic proppant within the range of 5-20:1 maintains acidic properties and high hydrothermal stability. This effectively addresses the problem of poor in-situ hydrocarbon generation performance in resources such as medium- and low-maturity shale oil and oil shale due to low acid content and strength. It also overcomes the drawback of ceramsite proppants, which often lack support for narrow and micro-crevices.

[0099] The elemental analysis results of the oil produced by pyrolysis of oil shale after adding different catalytic proppants are shown in Table 2.

[0100] Table 2

[0101]

[0102]

[0103] The results in Table 2 show the effect of the catalytic proppant on the properties of the oil product from oil shale conversion. Elemental analysis of the product oil shows that the addition of the catalytic proppant in Examples 1-4 improves the H / C ratio of the product oil, resulting in a higher saturation of the produced oil. Excellent deoxidation and denitrification modification effects are also exhibited, which improves the quality of the product oil. In Comparative Example 1, i.e., Test Example 5, the weight ratio of clay to SO3H groups is 3:1. When the content of SO3H groups is high, the effect is not significantly increased, but the cost increases significantly. In Comparative Example 2, i.e., Test Example 6, the weight ratio of clay to SO3H groups is 30:1, and its deoxidation and denitrification modification effect is poor. Therefore, the weight ratio of clay to SO3H groups in the catalytic proppant is within the range of 5-20:1, maintaining the acidic properties, resulting in a higher saturation of the produced oil, and exhibiting an excellent deoxidation and denitrification modification effect.

[0104] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A bulk catalytic proppant, characterized in that: The catalytic support comprises: modified clay with SO3H groups and an additive; wherein the weight ratio of clay to SO3H groups in the modified clay with SO3H groups is 5-20:1; The auxiliary agent includes an additive and a structural auxiliary agent, wherein the additive is selected from one or more of kaolin, bauxite, and dolomite, and the structural auxiliary agent is selected from one or more of citric acid, cellulose, and starch; The modified clay with SO3H groups is obtained by sequentially subjecting clay to acid activation, thiolization, wet ball milling grafting and oxidation.

2. The catalytic proppant according to claim 1, characterized in that The weight ratio of the modified clay with SO3H groups to the auxiliary agent is 1-10:1; And / or, in the auxiliary agent, the content of the structural auxiliary agent is 5-15 wt %, and the content of the additive is 85-95 wt %.

3. The catalytic proppant according to claim 1 or 2, characterized in that: The particle size of the catalytic proppant is 0.1-2 mm; And / or, the acid content of the proppant is greater than 1 mmol / g.

4. A method for preparing a bulk catalytic proppant, characterized in that: The following steps are involved: (1) After the clay is activated with acid, a thiol-containing agent is added to perform wet ball milling grafting; (2) reacting the product obtained in step (1) with an oxidant to obtain a modified clay with a SO3H group; (3) mixing the modified clay with SO3H groups and the additive, granulating and calcining to obtain the bulk catalytic support; The auxiliary agent includes additives and structural auxiliary agents; the additives are selected from one or more of kaolin, bauxite, and dolomite, and the structural auxiliary agents are selected from one or more of citric acid, cellulose, and starch.

5. The preparation method according to claim 4, characterized in that In step (1), the acid is selected from one or more of hydrochloric acid, nitric acid, and sulfuric acid; And / or, the clay is selected from attapulgite clay and / or zeolite.

6. The preparation method according to claim 5, characterized in that The zeolite is clinoptilolite.

7. The preparation method according to claim 4 or 5, characterized in that The mercapto group-forming agent is selected from one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxysilane; And / or, the oxidant is selected from one or more of hydrogen peroxide, nitric acid, sodium hypochlorite, and peracetic acid.

8. The preparation method according to claim 6, characterized in that The mercapto group-forming agent is selected from one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxysilane; And / or, the oxidant is selected from one or more of hydrogen peroxide, nitric acid, sodium hypochlorite, and peracetic acid.

9. The preparation method according to any one of claims 4 to 6 and 8, characterized in that In the auxiliary agent, the content of the structural auxiliary agent is 5-15 wt %, and the content of the additive is 85-95 wt %.

10. The preparation method according to claim 7, characterized in that In the auxiliary agent, the content of the structural auxiliary agent is 5-15 wt %, and the content of the additive is 85-95 wt %.

11. The preparation method according to any one of claims 4 to 6, 8 and 10, characterized in that: The weight ratio of the modified clay with SO3H groups to the auxiliary agent is 1-10:1; And / or, the mass ratio of the clay to the acid, the thiol-forming agent, and the oxidizing agent is 1:3-6:0.3-3:1-9.

12. The preparation method according to claim 7, characterized in that The weight ratio of the modified clay with SO3H groups to the auxiliary agent is 1-10:1; And / or, the mass ratio of the clay to the acid, the thiol-forming agent, and the oxidizing agent is 1:3-6:0.3-3:1-9.

13. The preparation method according to claim 9, characterized in that The weight ratio of the modified clay with SO3H groups to the auxiliary agent is 1-10:1; And / or, the mass ratio of the clay to the acid, the thiol-forming agent, and the oxidizing agent is 1:3-6:0.3-3:1-9.

14. The preparation method according to any one of claims 4 to 6, 8, 10, 12 and 13, characterized in that: In step (3), the calcination temperature is 750-1100°C and the calcination time is 0.5-3h.

15. The preparation method according to claim 7, characterized in that In step (3), the calcination temperature is 750-1100°C and the calcination time is 0.5-3h.

16. The preparation method according to claim 9, characterized in that In step (3), the calcination temperature is 750-1100°C and the calcination time is 0.5-3h.

17. The preparation method according to claim 11, characterized in that In step (3), the calcination temperature is 750-1100°C and the calcination time is 0.5-3h.

18. Use of the bulk catalytic proppant according to any one of claims 1 to 3 and the bulk catalytic proppant prepared by the preparation method according to any one of claims 4 to 17 in shale fracturing micro-fracture support.

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