A slit-mesh sand trap and its application

Abstract

This invention provides a slotted mesh sand trap and its application. The slotted mesh sand trap includes a sand trap body and a heat-fusible adhesive outer layer. The sand trap body is composed of intertwined and coiled elastic polygonal prisms with a porous mesh structure. When heated, the slotted mesh sand trap of this invention releases the sand trap body, forming an effective "fence"-type interception dam in the fracturing fracture, effectively preventing the backflow of proppant and exhibiting high sand trapping and consolidation efficiency, superior to conventional fiber materials. Simultaneously, the porous structure of the sand trap body does not affect the fracture conductivity, overcoming the problems of low consolidation efficiency and reduced fracture conductivity due to pore blockage in traditional resin-coated sand.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well fracturing technology, specifically to a fracture mesh sand catcher and its application. Background Technology

[0002] Hydraulic fracturing is a key technology for developing low-permeability and unconventional oil and gas reservoirs. With the development of fracturing technology, especially shale oil and gas development, volumetric fracturing has developed rapidly, and the application scale of horizontal wells has gradually expanded. Under the fracturing theory of "high sand ratio, small particle size, and large scale," the problem of proppant backflow has also become increasingly prominent. The backflow and regurgitation of fracturing proppant will cause problems such as fracture closure, damage to downhole and surface equipment, and thus affect the normal production of oil and gas wells. Its main hazards are: 1. Proppant backflow and sand production, leading to fracture closure, increased skin coefficient, reduced fracture conductivity, and decreased oil and gas well productivity; 2. Backflowed proppant accumulation at the bottom of the well, burying oil and gas layers, causing damage to downhole equipment; 3. Repairs required for sand removal in the wellbore, affecting oil well production; 4. Backflowed sand from the proppant erodes the wellbore, surface pipelines, nozzles, separators, and other equipment, causing serious damage to surface production facilities.

[0003] The main technical measures currently adopted to address proppant backflow include: 1. Forced fracture closure technology, which uses controlled blowout to force fracture closure and reduce proppant backflow. However, its implementation is complex due to differences in geological conditions, construction conditions, and drainage conditions in different wells; 2. Application of resin-coated proppant, which forms a proppant network barrier through inter-proppant bonding. However, this technology can easily lead to a reduction in fracture conductivity, resulting in a decrease in fracturing effectiveness; 3. Fiber-filled technology, which utilizes the interaction of fibers and particles to form a spatial network structure, thereby achieving the purpose of suppressing proppant backflow. However, due to the linear structure of fibers, the sand control and sand prevention effect is poor.

[0004] The processes for sand control in oil and gas wells involve both chemical and physical sand control methods. Among the existing technologies, patent CN201710112615.7 discloses a water-based resin sand control agent and its preparation method; patent CN202010550860.8 discloses the application of an aqueous solution diluent composition in oil and gas well sand control; patent CN201310223022.X discloses a proppant backflow control system and control method based on magnetic proppant; and patent CN201310657062.5 discloses a fracturing method to prevent proppant backflow in low-permeability horizontal wells. These technologies involve chemical composite coatings and magnetic proppants. Patent CN201811622690.9 discloses a water-soluble biodegradable fiber and its preparation method, which relates to water-soluble cellulose to prevent proppant backflow.

[0005] The aforementioned proppant anti-backflow technologies primarily employ a combination of chemical coatings and processes. Water-soluble cellulose uses fibers to form a network physical structure with the proppant, but this structure has low trapping capacity and cannot form an effective "fence" morphology in fracturing fractures. Furthermore, the fibers are easily dissolved, resulting in poor long-term sand control and stabilization effects. Conventional resin-coated sand exhibits low consolidation efficiency in fractures, especially in environments with water or oil. Consolidation efficiency can only be improved by thickening the coating layer or increasing the amount of consolidating sand, but this reduces the conductivity of the pores between proppant particles. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention aims to provide a slit-mesh sand trapping agent and its application. After entering the fracture, the slit-mesh sand trapping agent releases, extends, and intertwines with each other, thereby effectively fixing and trapping the fracturing proppant and preventing the proppant from flowing back and being expelled.

[0007] To achieve the above objectives, the present invention provides a slit-mesh sand trapping agent, which includes a sand trapping agent body and a heat-melting adhesive outer layer. The sand trapping agent body is composed of elastic polygonal prisms that are intertwined and curled, and the elastic polygonal prisms have a porous mesh structure.

[0008] In the fractured sand catching agent of this invention, the bonding outer layer can fix the elastic polygonal prisms into a curled shape at room temperature. The porous structure in the elastic polygonal prisms allows fluid to pass smoothly through the fractured sand catching agent. The fractured sand catching agent of this invention consists of a bonding outer layer covering the sand catching agent body, so that the sand catching agent body is in a coiled (non-stretched) state when it is sent into the wellbore, preventing it from popping out prematurely during pumping and causing blockage. When the fractured sand catching agent enters the fracturing fracture, its bonding outer layer material melts upon heating and releases the sand catching agent body, and the elastic polygonal prisms therein are released and stretched due to their elasticity. After the fracturing fracture closes, the stretched elastic polygonal prisms (the released sand catching agent) form a "fence"-type interception dam in the fracture, effectively intercepting the proppant and preventing proppant backflow. At the same time, the large number of porous structures in the elastic polygonal prisms allows fluid to flow smoothly, thereby achieving sand catching without affecting the flow of fluid.

[0009] In the aforementioned slit-mesh sand-catching agent, preferably, the surfaces of the edges and / or faces of the elastic polygonal prism are provided with a branched structure, more preferably an irregular branched structure. The elastic polygonal prism in this invention is formed by cutting and rolling a porous polyurethane matrix, while simultaneously forming a rough and uneven branched structure on its surface.

[0010] In the slit-mesh sand trapping agent of the present invention, the branched structure on the surface of the elastic polygonal prism makes it easier for the released elastic polygonal prism to entangle and form a larger spatial structure. This forms a more stable "fence" type proppant interception dam inside the supporting crack, preventing proppant backflow and improving the sand trapping and fixing effect.

[0011] In the above-mentioned slit-mesh sand trap, preferably, the shape of the elastic polyhedron is selected from one or more combinations of triangular prisms, quadrangular prisms, and pentagonal prisms.

[0012] In the above-mentioned slit-mesh sand trap, preferably, in the unfolded state, the ratio of the cross-sectional diameter to the length of the elastic polygonal prism is 1:10-5:1.

[0013] In the above-mentioned slit-mesh sand trap, preferably, the length of the elastic polygonal prism is 2-12 mm.

[0014] Traditional water-soluble cellulose fibers form a network structure with a proppant. The fibers are approximately 10 mm long and 10-50 micrometers in diameter, with a relatively smooth surface that makes them difficult to entangle. Therefore, the resulting structure has low aggregation capacity and cannot form an effective "fence"-like interception dam in fracturing fractures, resulting in poor sand control and fixation. The slit-mesh sand-trapping agent of this invention exhibits significantly better sand-trapping performance than conventional fiber materials and has a better effect in preventing proppant backflow.

[0015] In the aforementioned slotted mesh sand-catching agent, preferably, the pore size of the mesh structure is 0.2-1 mm, and the mesh density is 20-60 ppi. Slotted mesh sand-catching agents with this pore size are suitable for capturing proppant particles of 20 / 40, 30 / 50, 70 / 140, and combinations thereof. The pore size in the elastic polygonal prism of the slotted mesh sand-catching agent should be smaller than the particle size of the proppant to prevent the proppant from passing through the mesh and affecting its capture.

[0016] In the above-mentioned slit-mesh sand trap, preferably, the thickness of the adhesive outer layer is 0.5-2 mm.

[0017] In the above-mentioned slit-net sand trap, preferably, the slit-net sand trap has a regular or irregular spherical, spindle-shaped or tetragonal shape, more preferably an irregular spherical shape.

[0018] In the aforementioned slit-mesh sand-catching agent, preferably, the material of the sand-catching agent body is selected from polyurethane, flexible polyvinyl chloride, acrylic resin, polyglycolic acid, or polylactic acid. The sand-catching agent body (elastic polygonal prism) can be made of materials that are insoluble in or soluble in oil and water, and can be made of biodegradable or non-biodegradable materials.

[0019] In the above-mentioned slit-mesh sand trap, preferably, the softening point of the outer bonding material is 50-120℃.

[0020] In the above-mentioned slit-mesh sand trap, preferably, the material of the adhesive outer layer is selected from chlorinated paraffin, bone glue, C5 petroleum resin, C9 petroleum resin or terpene resin.

[0021] The bonding outer layer is made of a fragile material that can be thermally melted at low temperatures, and the melting rate of this material controls the melting time. The bonding outer layer of the slotted sand catcher gradually softens under temperatures above its softening point. Under the impact of fluid, the sand catcher body is released and extended. As the temperature continues to rise, the bonding outer layer softens and melts further, becoming flowable and miscible with the crude oil in the formation, eventually dissolving and disappearing completely.

[0022] In the aforementioned slit-net sand trap, preferably, the surface of the adhesive outer layer is coated with a surfactant layer. Since the adhesive outer layer material has poor hydrophilicity, coating it with a surfactant can improve wettability, which is beneficial for the uniform dispersion of the slit-net sand trap in water.

[0023] The present invention also provides an application of the above-mentioned fractured sand catcher in oil and gas well fracturing, wherein the fractured sand catcher is used to prevent proppant backflow.

[0024] In the above applications, preferably, the amount of the slotted mesh sand trap is 0.002-0.008 times the amount of proppant used in the same stage.

[0025] In the above applications, preferably, the slotted sand catcher is added before the last proppant slug during the proppant particle size change; after adding the slotted sand catcher, the fracturing fluid injection time continues for ≥20 minutes. This ensures that the bonding outer layer softens and is destroyed before the pumping ends, releasing the encapsulated sand catcher material.

[0026] Traditional consolidated sands, especially in water- or oil-contaminated environments, exhibit low efficiency in forming effective consolidation within fractures, requiring thicker coatings and larger quantities of sand to achieve the desired effect. In contrast, the fracture-mesh sand-catching agent of this invention achieves excellent sand-catching and consolidation effects with a much smaller dosage, only 0.002-0.008 times the amount added in the final sand-addition stage of the fracturing pump injection process. Furthermore, it requires no specialized addition equipment, simplifying application. In comparison, traditional resin-coated sands require 3-5 tons at the end, while fiber materials necessitate specialized addition equipment and complex application methods.

[0027] The fracture mesh sand catcher of this invention can be added directly to the mixing tank of a sand mixing truck or added through the high-pressure manifold of a ball-feeding device. The fracture mesh sand catcher of this invention is applicable to various fracturing methods, including conventional hydraulic fracturing, end-stage desanding fracturing, and reservoir stimulation processes such as stratified fracturing of vertical / directional wells, segmented fracturing of horizontal wells, repeated fracturing of old wells, and end-stage desanding fracturing.

[0028] The technical solution provided by this invention has the following beneficial effects:

[0029] The slit-mesh sand-catching agent of this invention releases its bulk form upon heating, creating an effective "fence"-like interception dam within the fracturing fracture. This effectively prevents proppant backflow and exhibits high sand-catching and consolidation efficiency, superior to conventional fiber materials. Simultaneously, the sand-catching agent's mesh structure does not affect the fracture's conductivity, overcoming the problems of low consolidation efficiency and reduced fracture conductivity due to pore blockage in traditional resin-coated sand. The slit-mesh sand-catching agent of this invention requires a small dosage, does not require specialized addition equipment, and is simple to apply. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the slit mesh sand trap of the present invention;

[0031] Figure 2A This is a schematic diagram of a triangular prism structure;

[0032] Figure 2B This is a schematic diagram of a quadrangular prism structure;

[0033] Figure 3 This is a schematic diagram of the "fence"-type interception dam formed after the release and extension of the slit-mesh sand-catching agent body of the present invention. Detailed Implementation

[0034] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0035] This invention provides a slit-mesh sand trap, such as... Figure 1 As shown, the slit-mesh sand catcher includes a sand catcher body and a heat-fusible adhesive outer layer. The sand catcher body is composed of multiple intertwined and coiled elastic polygonal prisms. The lubrication point of the adhesive outer layer material is 50-120℃, and its surface is coated with a surfactant layer. The elastic polygonal prisms have a porous mesh structure with an average pore diameter of 0.2-1 mm and a mesh density of 20-60 ppi. The edges and / or faces of the elastic polygonal prisms are provided with a dendritic structure. For example... Figure 2A and Figure 2B The ratio of the diameter to the length of the cross section of the elastic polyprism in its unfolded state is 1:10-5:1, the length of the elastic polyprism is 2-12mm, and the shape of the elastic polyprism is a triangular prism, a quadrangular prism, or a pentagonal prism.

[0036] When this fracture-type sand catcher is introduced into the wellbore, it is in a coiled (non-stretched) state. After entering the fracturing fracture, its outer bonding material melts upon heating, releasing the sand catcher body. The elastic polygonal prisms within it then extend and expand. After the fracturing fracture closes, the extended elastic polygonal prisms (the released sand catcher) form a structure within the fracture, resembling... Figure 3The "fence" type interception dam shown effectively intercepts proppant, prevents proppant backflow, and achieves sand capture without affecting fluid flow.

[0037] The present invention will now be described in conjunction with specific embodiments.

[0038] Example 1

[0039] This embodiment provides a slit-mesh sand trapping agent, which includes a sand trapping agent body and a heat-fusible chlorinated paraffin 70 bonding outer layer (softening point 90°C). The sand trapping agent body is composed of multiple intertwined and curled polyurethane tetragonal prisms. The bonding outer layer is coated with a sodium dodecyl sulfate (SDS) surfactant layer. The slit-mesh sand trapping agent has an irregular spherical appearance with an outer tangent diameter of 3 mm. The polyurethane tetragonal prisms have a porous structure with a porous density of 25 ppi and an average porous diameter of 1.0 mm. The edges and / or faces of the polyurethane tetragonal prisms are provided with a branched structure. In the unfolded state, the length of the polyurethane tetragonal prism is 5 mm and the cross-sectional diameter is 5 mm.

[0040] Example 2

[0041] This embodiment provides a slit-mesh sand trapping agent, which includes a sand trapping agent body and a water-soluble terpene resin bonding outer layer (softening point 90°C). The sand trapping agent body is composed of multiple intertwined and curled polyglycolic acid tetragonal prisms. The bonding outer layer is coated with a nonylphenol polyoxyethylene ether (NP-10) surfactant layer. The slit-mesh sand trapping agent has an irregular sphere appearance with an outer tangent diameter of 8 mm. The polyglycolic acid tetragonal prisms have a porous mesh structure with a mesh density of 50 ppi and an average mesh diameter of 0.4 mm. The edges and / or facets of the polyglycolic acid tetragonal prisms are provided with a branched structure. In the unfolded state, the length of the polyglycolic acid tetragonal prism is 6 mm and the cross-sectional diameter is 1 mm.

[0042] Example 3

[0043] This embodiment provides a slit-mesh sand catcher, which includes a sand catcher body and an oil-soluble C9 petroleum resin bonding outer layer (softening point 120°C). The sand catcher body is composed of multiple intertwined and curled polylactic acid tetragonal prisms. The bonding outer layer is coated with a dodecanetrimethylammonium chloride (1231) surfactant layer. The slit-mesh sand catcher has an irregular sphere appearance with an outer tangent diameter of 5 mm. The polylactic acid tetragonal prisms have a mesh structure with a mesh density of 20 ppi and an average mesh diameter of 0.6 mm. The edges and / or faces of the polylactic acid tetragonal prisms are provided with a branched structure. In the unfolded state, the polyurethane tetragonal prism has a length of 10 mm and a cross-sectional diameter of 1 mm.

[0044] Example 4

[0045] This embodiment provides a slit-mesh sand trapping agent, which includes a sand trapping agent body and a water-soluble bone glue adhesive outer layer. The sand trapping agent body is composed of multiple intertwined and curled flexible polyvinyl chloride triangular prisms. The surface of the adhesive outer layer is coated with a sodium dodecylbenzenesulfonate (SDBS) surfactant layer. The slit-mesh sand trapping agent has an irregular sphere appearance with an outer tangential diameter of 8 mm. The flexible polyvinyl chloride triangular prisms have a porous structure with a porous density of 60 ppi and an average porous diameter of 0.3 mm. The edges and / or faces of the flexible polyvinyl chloride triangular prisms are provided with a branched structure. In the unfolded state, the length of the flexible polyvinyl chloride triangular prism is 12 mm and the cross-sectional diameter is 3 mm.

[0046] Comparative Example 1

[0047] This embodiment provides a slit mesh sand trap, which is made of soft polyvinyl chloride triangular prisms wound together; wherein, the mesh density is 60ppi, the average mesh diameter is 0.3mm, the length of the triangular prism is 12mm, and the cross-sectional diameter is 3mm.

[0048] Comparative Example 2

[0049] This embodiment provides a slit-mesh sand trap, which comprises polyurethane quadrangular prisms wound together, wherein the mesh density is 25 ppi and the average mesh diameter is 1.0 mm; the length of the quadrangular prisms is 5 mm and the cross-sectional diameter is 5 mm.

[0050] Experimental Example 1

[0051] This experimental example was used to evaluate the sand-catching efficiency of the fractured sand-catching agent in Example 1. The short-term conductivity test method specified in SY / T6302-2019, "Test Method for the Conductivity of Fracturing Proppants," was adopted. No filter was installed at the outlet. The sand-catching efficiency of the fractured sand-catching agent in Example 1 and its effect on the conductivity of the proppant fractures were tested at an experimental temperature of 80℃. The results are shown in Table 1.

[0052] Table 1. Evaluation results of sand-catching efficiency of the slit-mesh sand-catching agent in Example 1.

[0053]

[0054] As shown in the table above, the externally coated tetragonal prism-shaped mesh sand-catching agent exhibits good sand-catching efficiency without affecting the fracture conductivity. The optimal effect is achieved when the mass ratio of sand-catching agent to proppant is 0.01, resulting in a fracture conductivity of 107.30 μm. 2 The sand trapping depth was increased by 5.01% compared to no sand trapping agent was added; the sand trapping efficiency was 84.9%.

[0055] Experiment Example 2

[0056] This experimental example was used to evaluate the sand-catching efficiency of the fractured sand-catching agent in Example 2. The short-term conductivity test method specified in SY / T6302-2019, "Test Method for the Conductivity of Fracturing Proppants," was adopted. No filter was installed at the outlet. The sand-catching efficiency of the fractured sand-catching agent in Example 2 and its effect on the conductivity of the proppant fractures were tested at a temperature of 90℃. The results are shown in Table 2.

[0057] Table 2. Evaluation results of sand trapping efficiency of the slit mesh sand trapping agent in Example 2.

[0058]

[0059] As shown in the table above, the externally coated tetragonal prism-shaped sand-catching agent exhibits good sand-catching efficiency without affecting the fracture conductivity. When its mass ratio to proppant is 0.008, the fracture conductivity is 6.81 μm. 2 The sand trapping depth was increased by 2.9% compared to no sand trapping agent was added; the sand trapping efficiency was 85.0%.

[0060] Experimental Example 3

[0061] This experimental example was used to evaluate the sand-catching efficiency of the fractured sand-catching agent in Example 3. The short-term conductivity test method specified in SY / T6302-2019, "Test Method for the Conductivity of Fracturing Proppants," was adopted. No filter was installed at the outlet. The sand-catching efficiency of the fractured sand-catching agent in Example 3 and its effect on the conductivity of the proppant fractures were tested at a temperature of 120℃. The results are shown in Table 3.

[0062] Table 3. Evaluation results of sand trapping efficiency of the slit mesh sand trapping agent in Example 3.

[0063]

[0064] As shown in the table above, the externally coated tetragonal prism-shaped sand-catching agent exhibits good sand-catching efficiency without affecting the fracture conductivity. The optimal effect is achieved when its mass ratio to proppant is 0.006, resulting in a fracture conductivity of 6.92 μm. 2 The sand trapping depth was increased by 4.5% compared to no sand trapping agent was added; the sand trapping efficiency was 92.0%.

[0065] Experiment Example 4

[0066] This experimental example was used to evaluate the sand-catching efficiency of the slotted mesh sand-catching agent in Example 3. A simulated field test was conducted using a combination of particle size proppants to evaluate the sand-catching efficiency of a composite proppant with a ratio of 40 / 70 quartz sand to 20 / 40 ceramsite (3:1 by mass). The short-term conductivity test method specified in SY / T6302-2019 (Test Method for the Conductivity of Fracturing Proppants) was adopted, with no filter screen at the outlet. The sand-catching efficiency of the slotted mesh sand-catching agent in Example 3 and its effect on the conductivity of the proppant fractures were tested at a temperature of 120℃. The results are shown in Table 4.

[0067] Table 4. Evaluation results of sand trapping efficiency of the slit mesh sand trapping agent in Example 3.

[0068]

[0069] As shown in the table above, for the composite proppant 40 / 70 quartz sand: 20 / 40 ceramsite = 3:1 (mass ratio), the best effect is achieved when the mass ratio of the outer prism-shaped fracture mesh sand catcher to the proppant is 0.006, with a fracture conductivity of 11.74 μm. 2 The sand trapping density increased by 6.0% compared to no sand trapping agent, and the sand trapping efficiency was 91.1%. This demonstrates that the slit-mesh sand trapping agent exhibits high sand trapping efficiency and fracture conductivity for composite particle size proppant.

[0070] Experimental Example 5

[0071] This experiment was used to evaluate the sand-catching efficiency of the slotted sand-catching agent in Example 4. The short-term conductivity test method specified in SY / T6302-2019, "Test Method for the Conductivity of Fracturing Proppants," was adopted. No filter was installed at the outlet. The sand-catching efficiency of the slotted sand-catching agent in Example 4 and its effect on the conductivity of the proppant fractures were tested at a temperature of 50℃. The results are shown in Table 5.

[0072] Table 5. Evaluation results of sand trapping efficiency of the slit mesh sand trapping agent in Example 4.

[0073]

[0074] As shown in the table above, the triangular prism-type fracture mesh sand-catching agent of Example 4 has good sand-catching efficiency without affecting the fracture conductivity. It exhibits the best effect when its mass ratio to proppant is 0.008, with a fracture conductivity of 6.91 μm. 2 The sand trapping depth increased by 9.55% compared to no sand trapping agent was added; the sand trapping efficiency was 92.9%.

[0075] Based on the evaluation results of the sand-catching efficiency of the slit-mesh sand-catching agent in Examples 1-4 above, it can be seen that the slit-mesh sand-catching agent of the present invention has good crack flow conduction ability and sand prevention and sand fixation effect.

[0076] Experimental Example 6

[0077] This experimental example was used to evaluate the sand-catching efficiency of the fractured sand-catching agent in Comparative Example 1. The short-term conductivity test method specified in SY / T6302-2019, "Test Method for the Conductivity of Fracturing Proppants," was adopted. No filter was installed at the outlet. The sand-catching efficiency of the fractured sand-catching agent in Comparative Example 1 and its effect on the conductivity of the proppant fractures were tested at a temperature of 50℃. The results are shown in Table 6.

[0078] Table 6 shows the evaluation results of the sand-catching efficiency of the slit mesh sand-catching agent in Comparative Example 1.

[0079]

[0080] As shown in the table above, the triangular prism-type fracture mesh sand catcher of Comparative Example 1, with a mass ratio of 0.004 to proppant, exhibits good performance, with a fracture conductivity of 6.44 μm. 2 The sand trapping depth was increased by 3.04% compared to no sand trapping agent was added; the sand trapping efficiency was 83.4%.

[0081] Comparative Example 1, lacking an adhesive outer layer, exhibits poor sand-catching efficiency. In contrast, the slit-mesh sand-catching agent of this invention, by incorporating an adhesive outer layer, ensures that the entangled sand-catching agent body remains intertwined under the resistance of the adhesive outer layer. This prevents the sand-catching agent body from springing open and causing blockage during pumping, thereby improving the pumping effect and making it easier for the sand-catching agent to enter the cracks. The released sand-catching agent body (polygonal prisms) intertwines with each other in the cracks, enhancing the sand-prevention and sand-fixing effects.

Claims

1. A slit-net sand catcher, comprising a sand catcher body and a heat-meltable adhesive outer layer, the sand catcher body being composed of elastic multi-prismatic bodies that are intertwined with each other and in a curled state, the elastic multi-prismatic bodies having a mesh structure therein. wherein In the expanded state, the ratio of the cross-sectional diameter to the length of the elastic multi-prismatic body is 1:10-5:

1. The length of the elastic multi-prismatic body is 2-12 mm. The mesh structure has a pore size of 0.2-1 mm and a mesh density of 20-60 ppi. The material of the sand catcher body is selected from polyurethane, soft polyvinyl chloride, acrylic resin, polyglycolic acid or polylactic acid. The softening point of the material of the adhesive outer layer is 50-120℃.

2. The net-sand-sealing agent according to claim 1, wherein The edges and / or the surfaces of the elastic multi-prismatic body are provided with a dendritic structure.

3. The net-sand-sealing agent according to claim 1, wherein, The shape of the elastic multi-prismatic body is selected from one or a combination of more than two of triangular prism, quadrangular prism and pentagonal prism.

4. The net-sand-sealing agent according to claim 1, wherein, The thickness of the adhesive outer layer is 0.5-2 mm.

5. The netting sand control agent of claim 1, wherein, The shape of the slit-net sand catcher is regular or irregular spherical, spindle or tetrahedral.

6. The net seeping sand agent according to claim 1, wherein, The material of the adhesive outer layer is selected from chlorinated paraffin, bone glue, C5 petroleum resin, C9 petroleum resin or terpene resin.

7. The net seeder of claim 1, wherein, The surface of the adhesive outer layer is coated with a surfactant layer.

8. Use of the mesh sand control agent of any one of claims 1 to 7 in the fracturing of oil and gas wells, wherein, The slit-net sand catcher is used for preventing the backflow of proppants.

9. Use according to claim 8, wherein, The amount of the slit-net sand catcher is 0.002-0.008 times the amount of proppants of the same stage.

10. Use according to claim 8, wherein, The slit-net sand catcher is added before the last proppant slug in which the size of the proppants changes; after the addition of the slit-net sand catcher, the time for continuing to pump the fracturing fluid is ≥20 min.

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