Oil-soluble temporary plugging agent based on fracturing proppant as skeleton and preparation method thereof

Abstract

The application discloses an oil-soluble temporary plugging agent based on a fracturing proppant as a skeleton and a preparation method, the skeleton comprises the fracturing proppant, and an oil-soluble coating layer is formed on the surface of the skeleton; the oil-soluble coating layer comprises, in terms of weight parts, 30-80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 20-40 parts of disulfide rosin and 0-30 parts of styrene-isoprene-styrene block copolymer (SIS); the oil-soluble temporary plugging agent comprises, in terms of weight parts, 55-90 parts of the fracturing proppant and 10-45 parts of the oil-soluble coating layer; the oil-soluble temporary plugging agent is prepared by taking the ceramic proppant as the skeleton and the oil-soluble material as the coating layer, the compressive strength of the oil-soluble temporary plugging agent can reach 60 MPa, the temperature resistance can reach 200 DEG C at the highest, the oil-soluble temporary plugging agent can be used for fracturing of an ultra-high temperature deep well with a depth of more than 6000 m, is friendly to the formation, causes no damage to the formation and is suitable for a wide temperature range.

Description

Technical Field

[0001] This invention belongs to the field of oilfield fracturing and production enhancement technology, specifically relating to an oil-soluble temporary plugging agent based on a fracturing proppant and its preparation method. Background Technology

[0002] Hydraulic fracturing is the main technology for the stimulation of low-permeability reservoirs, ultra-low-permeability reservoirs, and tight reservoirs. However, due to the heterogeneity within reservoirs, fracturing fluid will preferentially generate artificial fractures in relatively loose formations during hydraulic fracturing, resulting in other relatively tight formations not being fractured and stimulated. This reduces the actual efficiency of fracturing stimulation and cannot effectively improve reservoir recovery.

[0003] In-fracture temporary plugging and redirection fracturing technology involves adding a soluble plugging agent midway through fracturing to block the terminal of an artificially formed fracture, preventing it from extending in its original direction. By continuing hydraulic fracturing and increasing the pressure within the fracture, the artificial fracture changes direction, increasing its area affected by the formation and improving the drainage area for oil. After fracturing, as the fracturing fluid flows back to the wellbore and surface, and as oil flows towards the artificial fracture and wellbore, the plugging agent dissolves, keeping all artificial fractures open and providing a channel for oil to flow to the surface, effectively improving oil recovery.

[0004] Currently, temporary plugging agents used for oil well fracturing are divided into two categories: oil-soluble and water-soluble. Water-soluble temporary plugging agents are mainly used for large-scale volumetric fracturing and gas well fracturing, while conventional oil well fracturing mostly uses oil-soluble temporary plugging agents.

[0005] For example, Chinese invention patent CN120829539A, published on October 24, 2025, discloses a temperature-resistant, hydrophobic, oil-soluble temporary plugging agent for low-permeability reservoirs and its preparation method. The former is obtained by the following method: First, methyl methacrylate, acrylamide tetradecyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid monomer and initiator are dissolved in methanol to obtain an oil phase. Then, carboxymethyl cellulose is added to water to obtain an aqueous phase. Next, the oil phase is added to the aqueous phase to react and obtain a reaction product. Finally, the reaction product is washed with water, centrifuged and dried to obtain the final product. This invention, a temperature-resistant, hydrophobic, oil-soluble temporary plugging agent for low-permeability reservoirs, features excellent temperature and salt resistance and high plugging strength. Its temperature resistance is adjustable between 60 ℃ and 120 ℃, making it suitable for brine with a salinity of up to 40,000 mg / L. Its plugging strength reaches up to 80 MPa, enabling it to be used for temporary plugging and fracturing operations in low-permeability reservoirs at different temperatures. This effectively solves the shortcomings of existing temporary plugging agents, such as poor temperature and salt resistance and low plugging strength.

[0006] The oil-soluble temporary plugging agent in the above patent has a plugging strength as high as 80 MPa. Although it can be used for temporary plugging and fracturing operations in low-permeability reservoirs at different temperatures, its temperature resistance is adjustable between 60 ℃ and 120 ℃, meaning the maximum temperature resistance is 120 ℃. Well temperature and compressive strength are interdependent with well depth; the performance of fracturing materials must simultaneously meet the temperature and compressive strength requirements corresponding to the well depth, otherwise the lower limit will be used. A bottom-hole temperature of 120 ℃ generally corresponds to a well depth of around 3800 m and a bottom-hole pressure of around 38 MPa. Therefore, limited by the maximum temperature of 120 ℃, the oil-soluble temporary plugging agent prepared in the above patent is generally applicable to oil and gas wells with a depth not exceeding 3800 m. Moreover, the temperature resistance and plugging strength testing method described in the patent involves heating to the required temperature and holding for 2 hours, then gradually increasing the pressure, with a sudden pressure drop of more than 10% as the criterion for determining the compressive strength, which does not comply with the existing industry standard SYT 7811-2024. The patent for "Soluble Solid Temporary Plugging Agent for Fracturing and Acidizing" requires a stable pressure to maintain the plugging strength for 4 hours. However, this patent does not provide solubility data for the temporary plugging agent, as solubility rate is also an important indicator for fracturing temporary plugging agents. Therefore, there is an urgent need for an oil-soluble temporary plugging agent for fracturing with higher applicable temperature and compressive strength to simultaneously meet the requirements of fracturing operations in oil wells with a temperature resistance of over 130 ℃, a compressive strength of over 40 MPa, and a depth of over 4000 m. Summary of the Invention

[0007] The purpose of this invention is to provide an oil-soluble temporary plugging agent based on a fracturing proppant as a framework and its preparation method. It addresses the shortcomings of existing technologies by providing an oil-soluble temporary plugging agent for fracturing that simultaneously meets the requirements of high temperature resistance and high compressive strength, and has good solubility, as well as its preparation method.

[0008] The technical solution of the present invention is as follows: An oil-soluble temporary plugging agent based on a fracturing proppant skeleton comprises a skeleton and a coating layer. The skeleton, including the fracturing proppant, forms an oil-soluble coating layer on the surface of the skeleton, thus creating an oil-soluble temporary plugging agent with the fracturing proppant as the skeleton and the oil-soluble coating layer as the coating layer. The fracturing proppant provides support to the skeleton, offering rigid strength support against high pressure. The oil-soluble coating layer softens and bonds at a certain temperature, providing flexible strength support for sealing tightness and high pressure resistance, while also achieving good solubility.

[0009] Optionally, the oil-soluble coating layer comprises, by weight: 30-80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 20-40 parts of disproportionated rosin, and 0-30 parts of styrene-isoprene-styrene block copolymer (SIS).

[0010] Optionally, the oil-soluble temporary plugging agent comprises, by weight: 55-90 parts of fracturing proppant and 10-45 parts of oil-soluble coating layer, wherein the fracturing proppant includes quartz sand proppant or ceramsite proppant.

[0011] Optionally, the oil-soluble coating layer comprises, by weight: 80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS) and 20 parts of disproportionated rosin; the oil-soluble temporary plugging agent comprises, by weight: 90 parts of ceramsite proppant and 10 parts of oil-soluble coating layer.

[0012] The preparation method of an oil-soluble temporary plugging agent based on a fracturing proppant framework includes the following steps: Preparation of S1 oil-soluble coating layer: Oil-soluble styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-styrene block copolymer (SIS), and disproportionated rosin are added to a heating container equipped with a stirrer in proportion and heated and stirred until the materials are completely melted into a flowable liquid state to obtain an oil-soluble coating layer solution. S2 Coating: The fracturing proppant is added to a container equipped with a high-strength stirrer and stirred. At the same time, the oil-soluble coating solution obtained in step S1 is added to the fracturing proppant. The mixture is stirred and cooled until the oil-soluble coating layer solidifies on the surface of the fracturing proppant to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is an oil-soluble temporary plugging agent.

[0013] Optionally, the heating and melting temperature in step S1 is 230–250 °C, and the stirring time is 30–40 min.

[0014] Optionally, the stirring and cooling method in step S2 is to stir and cool naturally at the same time, and the cooling temperature after coating is not higher than 50 ℃. The particle size of the fracturing proppant is 20-60 mesh and the compressive strength is 15-63 MPa.

[0015] The beneficial effects of this invention are: The oil-soluble temporary plugging agent based on fracturing proppant as a framework and its preparation method disclosed in this application have the following advantages: 1. The oil-soluble temporary plugging agent of this application uses fracturing proppant as a skeleton, has good flow properties, high compressive strength and high temperature resistance. The compressive strength can reach 60 MPa; the temperature resistance can reach up to 200 ℃, and it can be used for fracturing of ultra-high temperature deep wells above 6000 m. 2. The oil-soluble temporary plugging agent of this application has a wide applicable temperature range. With formula adjustment, it can be applied to oil wells with temperatures ranging from 30 to 200 ℃. 3. The oil-soluble temporary plugging agent of this application is formation-friendly and does not damage the formation; the coating layer used is an oil-soluble material that can be completely dissolved in the crude oil in the formation. The residue after dissolution is a fracturing proppant, which is an essential material left in the formation after fracturing to improve the formation permeability.

[0016] This application uses ceramic proppant as a skeleton and oil-soluble material as a coating layer to prepare an oil-soluble temporary plugging agent with a compressive strength of up to 60 MPa and a maximum temperature resistance of 200 ℃. It can be used for fracturing of ultra-high temperature deep wells above 6000 m. It is formation-friendly and harmless, has a wide applicable temperature range, and has a simple preparation process, thus having broad application and market prospects. Detailed Implementation

[0017] The present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0018] Example 1 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS) and 20 parts of disproportionated rosin, start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 250 ℃ to prepare a liquid oil-soluble coating layer solution. S2 Coating: Start the stirrer in the zero-gravity mixer B, add 90 parts of ceramsite proppant with a compressive strength of not less than 63 MPa (50-60 mesh), add 10 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y1.

[0019] The oil-soluble temporary plugging agent Y1 prepared in Example 1 has a temperature resistance of 200 ℃ and a plugging strength of 60 MPa after 4 hours, making it suitable for fracturing ultra-high temperature deep oil wells above 6000 m. Detailed experimental data are shown in Table 1.

[0020] Example 2 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 10 parts of disproportionated rosin, and 10 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 250 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 80 parts of ceramsite proppant with a compressive strength of not less than 56 MPa (40-60 mesh), add 20 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y2. The oil-soluble temporary plugging agent Y2 prepared in Example 2 has a temperature resistance of 160 ℃ and a plugging strength of 50 MPa after 4 hours, and can be used for fracturing in oil wells at a depth of 4000~5000 m. Detailed experimental data are shown in Table 1.

[0021] Example 3 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 70 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 20 parts of disproportionated rosin, and 10 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 240 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 75 parts of ceramsite proppant with a compressive strength of not less than 49 MPa (40-60 mesh), add 25 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y3. The oil-soluble temporary plugging agent Y3 prepared in Example 3 has a temperature resistance of 130 ℃ and a plugging strength of 40 MPa after 4 hours, and can be used for fracturing in oil wells at a depth of 3000~4000 m. Detailed experimental data are shown in Table 1.

[0022] Example 4 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 60 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 30 parts of disproportionated rosin, and 10 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 240 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 70 parts of ceramsite proppant with a compressive strength of not less than 42 MPa (40-60 mesh), add 30 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y4. The oil-soluble temporary plugging agent Y4 prepared in Example 4 has a temperature resistance of 100 ℃ and a plugging strength of 30 MPa after 4 hours, and can be used for fracturing in oil wells at a depth of 2500~3000 m. Detailed experimental data are shown in Table 1.

[0023] Example 5 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 50 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 30 parts of disproportionated rosin, and 20 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 240 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 65 parts of ceramsite proppant with a compressive strength of not less than 35 MPa (20-40 mesh), add 35 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y5. The oil-soluble temporary plugging agent Y5 prepared in Example 5 has a temperature resistance of 80 ℃ and a plugging strength of 25 MPa maintained after 4 hours. It can be used for fracturing in oil wells at a depth of 2000~2500 m. Detailed experimental data are shown in Table 1.

[0024] Example 6 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 40 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 40 parts of disproportionated rosin, and 20 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 240 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 60 parts of ceramsite proppant with a compressive strength of not less than 28 MPa (20-40 mesh), add 40 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y6. The oil-soluble temporary plugging agent Y6 prepared in Example 6 has a temperature resistance of 60 ℃ and a plugging strength of 20 MPa maintained after 4 hours. It can be used for fracturing in oil wells at depths of 1500~2000 m. Detailed experimental data are shown in Table 1.

[0025] Example 7 Preparation of S1 oil-soluble coating layer: Start the stirrer in container A, add 30 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 40 parts of disproportionated rosin, and 30 parts of styrene-isoprene-styrene block copolymer (SIS, D4433 P, produced by Kraton Polymers, USA), start electric heating, and stir at a constant temperature for 30 min after the temperature rises to 230 ℃ to prepare a liquid oil-soluble coating layer solution; S2 Coating: Start the stirrer in the zero-gravity mixer B, add 55 parts of ceramsite proppant with a compressive strength of not less than 21 MPa (20-40 mesh), add 45 parts of the oil-soluble coating layer solution prepared in step S1, continue stirring, and cool naturally while stirring until the material temperature drops below 50 ℃ to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is oil-soluble temporary plugging agent Y7. The oil-soluble temporary plugging agent Y7 prepared in Example 7 has a temperature resistance of 50 ℃, maintains a plugging strength of 15 MPa after 4 hours, and its surface coating can be completely dissolved at 25 ℃. It can be used for fracturing in oil wells at depths of 800~1500 m. Detailed experimental data are shown in Table 1.

[0026] Comparative Example 1 Comparative Example 1 adopted the technical solution and preparation method of the prior art document (CN120829539A) and conducted relevant performance tests. The oil-soluble temporary plugging agent D1 prepared in Comparative Example 1 has a temperature resistance of 120 ℃ and a plugging strength of 35 MPa after 4 hours. Detailed experimental data are shown in Table 1.

[0027] The specific laboratory procedures for performance testing are as follows: 1. Solubility test: According to the industry standard SYT 7811-2024 Soluble Solid Temporary Plugging Agents for Fracturing and Acidizing, the solubility of granular temporary plugging agents should reach a solubility of not less than 95% after 120 hours.

[0028] The operation was first conducted according to the methods specified in sections 7.4.1.1 to 7.4.1.4 of the industry standard SYT 7811-2024, "Soluble Solid Temporary Plugging Agents for Fracturing and Acidizing." The test liquid was kerosene, the weight of the temporary plugging agent was accurate to 2.00 g, and the test temperatures were the temperatures achieved according to the temperature resistance capabilities in Examples 1 to 7. The specific operation procedures following section 7.4.1.4 are as follows: Wash the centrifuge tube with 100 ml of 0.5% OP-10 distilled water solution and centrifuge three times to separate the kerosene from the bottom of the centrifuge tube. Transfer the centrifuged solids to a weighed evaporating dish with a mass of m. Rinse the bottom of the centrifuge tube three times with distilled water, pouring the rinsing solution into the evaporating dish each time to ensure that all solids are completely transferred.

[0029] Place the evaporating dish in a 105 ℃ constant temperature drying oven and evaporate until constant weight, then record the mass m1.

[0030] Then, the solids in the evaporating dish were burned with a flame torch for 3 minutes. The evaporating dish containing the solids was cooled and weighed, and the mass m2 was recorded. The weight of the insoluble matter was (m1-m2) g. The weight of the fracturing proppant in the 2.00 g temporary plugging agent sample was (m2-m) g. The weight of the oil-soluble coating layer in the temporary plugging agent was [2.00-(m2-m)] g.

[0031] It should be noted that the above solubility test method is a reasonable adaptation based on the industry standard "SYT 7811-2024 Soluble Solid Temporary Plugging Agents for Fracturing and Acidizing". The solid separation in the evaporation dish is burned with a flame torch in order to accurately distinguish between "undissolved coating layer" and "support agent as core layer".

[0032] The proportion of oil-soluble and insoluble matter μ1 is calculated according to formula (1): (1) The solubility μ2 is calculated according to formula (2): μ2 = 1 - μ1(2) 2. Sealing strength test: The plugging strength test was conducted in accordance with 7.5.2.3 of SYT 7811-2024 Soluble Solid Temporary Plugging Agent for Fracturing and Acidizing, except that the maximum pressure of 20 MPa specified in d) was changed to the plugging pressure under the 4-hour plugging strength maintenance conditions corresponding to Examples 1 to 7.

[0033] Table 1. Experimental data for the examples and comparative examples.

[0034] The following conclusions can be drawn from the experimental data in Table 1: (1). Comparing the experimental data of Examples 1 to 7, it can be seen that, relatively speaking, the oil-soluble temporary plugging agent of Example 1 reached the maximum experimental temperature of 200 ℃ and the plugging strength of 60 MPa, respectively. This indicates that the effect of the binary oil-soluble coating layer of "styrene-ethylene-propylene-styrene block copolymer (SEPS) - disproportionated rosin" is better than that of the ternary oil-soluble coating layer of "styrene-ethylene-propylene-styrene block copolymer (SEPS) - disproportionated rosin - styrene-isoprene-styrene block copolymer (SIS)". (2). Comparing the experimental data of Examples 1-3 and Comparative Example 1, it can be seen that, according to the test method of "SYT 7811-2024 Soluble Solid Temporary Plugging Agent for Fracturing and Acidizing", under the same experimental conditions, Examples 1-3 not only had experimental temperatures of 130℃-200℃ that were higher than the experimental temperature of 120℃ in Comparative Example 1, but also had pressure resistance of 40-60 MPa that were higher than the 35 MPa in Comparative Example 1. In addition, the solubility in oil was also relatively higher. This indicates that the temperature resistance, pressure resistance, and oil solubility of Examples 1-3 were all better than those of Comparative Example 1.

[0035] It should be noted that the solubility of the temporary plugging agent is an important indicator for fracturing temporary plugging agents. The higher the solubility of the temporary plugging agent, the lower the residue of the temporary plugging agent in the formation after fracturing, and the lower the impact on the plugging of the gaps between the proppant in the formation.

[0036] Laboratory test data on the solubility of temporary plugging agents reflect the solubility rate; a higher solubility rate indicates lower insoluble matter content. While there are currently no industry standards for oil-soluble temporary plugging agents, according to the industry standard "SYT 7811-2024 Soluble Solid Temporary Pluging Agents for Fracturing and Acidizing," the solubility performance of granular temporary plugging agents should reach a solubility rate of no less than 95% after 120 hours, meaning that insoluble matter accounts for less than 5% of the soluble temporary plugging material.

[0037] In summary, this application uses ceramsite proppant as the skeleton and oil-soluble material as the coating layer to prepare an oil-soluble temporary plugging agent. The oil-soluble coating layer, by weight, comprises: 80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS) and 20 parts of disproportionated rosin; the oil-soluble temporary plugging agent, by weight, comprises: 90 parts of ceramsite proppant and 10 parts of oil-soluble coating layer; the compressive strength can reach 60 MPa; the maximum temperature resistance can reach 200 ℃, and it can be used for fracturing in ultra-high temperature deep wells above 6000 m.

[0038] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil-soluble temporary plugging agent based on fracturing proppant as a framework, characterized in that: The system comprises a framework and a coating layer. Based on the framework, the framework includes a fracturing proppant. The coating layer forms an oil-soluble coating layer on the surface of the framework, thereby forming an oil-soluble temporary plugging agent with the fracturing proppant as the framework and the oil-soluble coating layer as the coating layer. The fracturing proppant provides support to the framework, providing rigid strength support for high pressure resistance. The oil-soluble coating layer acts as the coating layer, softening and bonding at a certain temperature, providing flexible strength support for sealing tightness and high pressure resistance, and achieving the goal of good solubility.

2. The oil-soluble temporary plugging agent based on fracturing proppant as a framework according to claim 1, characterized in that: The oil-soluble coating layer comprises, by weight: 30-80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS), 20-40 parts of disproportionated rosin, and 0-30 parts of styrene-isoprene-styrene block copolymer (SIS).

3. The oil-soluble temporary plugging agent based on fracturing proppant as a framework according to claim 2, characterized in that: The oil-soluble temporary plugging agent comprises, by weight: 55-90 parts of fracturing proppant and 10-45 parts of oil-soluble coating layer, wherein the fracturing proppant includes quartz sand proppant or ceramsite proppant.

4. The oil-soluble temporary plugging agent based on fracturing proppant as a framework according to claim 3, characterized in that: The oil-soluble coating layer comprises, by weight: 80 parts of styrene-ethylene-propylene-styrene block copolymer (SEPS) and 20 parts of disproportionated rosin; the oil-soluble temporary plugging agent comprises, by weight: 90 parts of ceramsite proppant and 10 parts of oil-soluble coating layer.

5. The method for preparing the oil-soluble temporary plugging agent based on fracturing proppant as a framework according to any one of claims 1 to 4, characterized in that: Includes the following steps: Preparation of S1 oil-soluble coating layer: Oil-soluble styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-styrene block copolymer (SIS), and disproportionated rosin are added to a heating container equipped with a stirrer in proportion and heated and stirred until the materials are completely melted into a flowable liquid state to obtain an oil-soluble coating layer solution. S2 Coating: The fracturing proppant is added to a container equipped with a high-strength stirrer and stirred. At the same time, the oil-soluble coating solution obtained in step S1 is added to the fracturing proppant. The mixture is stirred and cooled until the oil-soluble coating layer solidifies on the surface of the fracturing proppant to obtain a semi-finished product. S3 Screening: The semi-finished product obtained in step S2 is screened using a double-layer screen with an upper layer of 5 mesh and a lower layer of 18 mesh. The finished product between the two screens is an oil-soluble temporary plugging agent.

6. The preparation method of the oil-soluble temporary plugging agent based on fracturing proppant as a framework according to claim 5, characterized in that: The heating and melting temperature in step S1 is 230–250 °C, and the stirring time is 30–40 min.

7. The preparation method of the oil-soluble temporary plugging agent based on fracturing proppant as a framework according to claim 5, characterized in that: The S2 step involves stirring and cooling simultaneously, with the cooling temperature after coating not exceeding 50 ℃. The fracturing proppant particles have a size of 20–60 mesh and a compressive strength of 15–63 MPa.

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