Chemical sand prevention device and method

Abstract

The invention discloses a chemical sand prevention device and method.The chemical sand prevention device comprises a sleeve, a sealing plate, a plurality of bags and a plurality of conveying pipes, the sleeve comprises a first pipe section and a second pipe section which are connected, an oil passing hole is formed in the pipe wall of the second pipe section, the bags are arranged on the second pipe section in a stacked mode in the inside-outside direction of the sleeve, and the sealing plate is arranged on the first pipe section. The bags are made of degradable materials and can be degraded at the high temperature, the filtering precision of the sand prevention materials in the bags is gradually increased in the direction from outside to inside, and the conveying pipes are used for conveying the sand prevention materials into the bags. A plurality of sand prevention layers with different filtering precisions are formed in the inner and outer directions of the casing pipe through the bags, sand grains in an oil layer can be effectively prevented from entering the casing pipe, and therefore a shaft and equipment are protected, and the yield of an oil well is increased. And compared with traditional multi-step and multi-equipment operation, arrangement of multiple sand prevention layers is achieved, and the operation process is greatly simplified.

Description

Technical Field

[0001] This invention relates to the field of oil well sand control technology, specifically to a chemical sand control device and method. Background Technology

[0002] With the rapid development of my country's petroleum industry, sand production during oil well extraction has become increasingly prominent. Sand production leads to decreased oil well output, equipment wear, increased production costs, and may even trigger oil well accidents. To address this issue, chemical sand control technology has been widely applied in oilfield extraction. Traditional chemical sand control methods mainly include injecting clay stabilizers, sand-fixing agents, organosilicon sand-fixing agents, and other chemical agents, as well as using deep sand control technology. These methods can prevent sand particles in the oil reservoir from migrating to the wellbore to a certain extent, but they have the following problems: traditional chemical sand control methods often require multiple steps and multiple equipment operations, increasing production costs and operational difficulty. Therefore, researching an efficient, environmentally friendly, and easy-to-operate chemical sand control device and method has become an urgent problem to be solved in the oilfield extraction field. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention provide a chemical sand control device and method.

[0005] The chemical sand control device of this invention includes a casing, a sealing plate, multiple bags, and multiple conveying pipes. The casing includes a first pipe section and a second pipe section connected together. The outer diameter of the first pipe section is larger than the outer diameter of the second pipe section, and an oil passage hole is formed on the pipe wall of the second pipe section. The sealing plate is connected to the second pipe section of the casing and seals the opening of the second pipe section away from the first pipe section. The multiple bags are stacked on the second pipe section along the inner and outer directions of the casing. The bags are arranged around the second pipe section, wherein the outer diameter of the outermost bag is less than or equal to the outer diameter of the first pipe section. The bags are made of biodegradable materials and can degrade at high temperatures. The multiple bags are used to fill sand control materials with different filtration accuracies, and the filtration accuracies of the sand control materials in the multiple bags gradually increase from the outside to the inside.

[0006] The multiple conveying pipes correspond one-to-one with the multiple bags. One end of the conveying pipe is connected to the corresponding bag, and the other end of the conveying pipe extends out of the first pipe section through the sleeve. The conveying pipe is used to convey sand-proof material into the bag.

[0007] In some embodiments, the plurality of bags include a first bag, a second bag, and a third bag arranged sequentially from the outside to the inside. The first bag is used to fill a first sand-proof material, the second bag is used to fill a second sand-proof material, and the third bag is used to fill a third sand-proof material. The first sand-proof material forms a low-precision filter layer, the second sand-proof material forms a medium-precision filter layer, and the third sand-proof material forms a high-precision filter layer.

[0008] In some embodiments, the first sand-proof material is a mixture of sand grains, walnut shells, and plastic granules, wherein the sand grains have a particle size of 4mm-8mm.

[0009] In some embodiments, the second sand-proof material is a mixture of gravel, glass microspheres and synthetic resin particles, wherein the gravel has a particle size of 2mm-4mm.

[0010] In some embodiments, the third sand-control material is a mixture of quartz sand and ceramic particles, wherein the particle size of the quartz sand is in the range of 0.5 mm to 1.2 mm.

[0011] In some embodiments, the oil passage is filled with multiple layers of stainless steel mesh.

[0012] In some embodiments, the chemical sand control device of the present invention further includes an oil pipe, one end of which extends into the second section of the casing, and the other end of which extends out of the first section. A packer located in the second section is provided between the oil pipe and the casing.

[0013] In some embodiments, the inlet end of the oil pipe is provided with a screen pipe, which is coaxially arranged with and connected to the oil pipe.

[0014] In some embodiments, the capsule is a thermoplastic starch capsule, and the pyrolysis temperature of the thermoplastic starch capsule is 60°C-90°C.

[0015] The chemical sand control method of this invention, applied to the chemical sand control device described in any of the above embodiments, includes the following steps:

[0016] S1. Lower the casing into the oil well and place the second section of the casing in the oil-producing layer of the well;

[0017] S2. The third sand-proof material is sequentially conveyed into the third bag, the second sand-proof material into the second bag, and the first sand-proof material into the first bag through the conveying pipe.

[0018] S3. After the material is conveyed, high-temperature gas is sequentially conveyed into the first bag, the second bag and the third bag through the conveying pipe. The first bag, the second bag and the third bag degrade under the action of the high-temperature gas, so that the sand-proof material filled in the first bag, the second bag and the third bag forms a multi-layer sand-proof layer in the direction of the inside and outside of the casing.

[0019] The chemical sand control device and method of this invention form multiple sand control layers with different filtration precipitates on the inside and outside of the casing using a bag. This effectively prevents sand particles from the oil layer from entering the casing, thereby protecting the wellbore and equipment and increasing oil well production. Compared to traditional multi-step, multi-equipment operations, this invention achieves the setting of multiple sand control layers through simple bag filling and high-temperature gas delivery, greatly simplifying the operation process. The simplified operation reduces the need for manpower and equipment, thus lowering production costs. The bag uses biodegradable materials, reducing environmental pollution. The degradation process is controllable, reducing potential safety risks during operation. By adjusting the type and precision of the sand control material inside the bag, it can adapt to different sand production conditions in different oil wells, improving the applicability of the device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the chemical sand control device according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the chemical sand control device according to an embodiment of the present invention before the bag is filled.

[0022] Figure 3 This is a schematic diagram of the chemical sand control device according to an embodiment of the present invention after the bag is filled.

[0023] Figure label:

[0024] 100. Chemical sand control device; 1. Casing; 101. First pipe section; 102. Second pipe section; 2. Sealing plate; 3. Bag; 301. First bag; 302. Second bag; 303. Third bag; 4. Conveyor pipe; 5. First sand control material; 6. Second sand control material; 7. Third sand control material; 8. Stainless steel mesh; 9. Oil pipe; 10. Packer; 11. Screen pipe. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] like Figures 1 to 3As shown, the chemical sand control device 100 of this embodiment includes a sleeve 1, a sealing plate 2, multiple bags 3, and multiple conveying pipes 4. The sleeve 1 includes a first pipe section 101 and a second pipe section 102 connected together, with the outer diameter of the first pipe section 101 being larger than the outer diameter of the second pipe section 102. An oil passage hole is formed in the wall of the second pipe section 102. The sealing plate 2 is connected to the second pipe section 102 of the sleeve 1 and seals the opening of the second pipe section 102 away from the first pipe section 101.

[0027] Multiple bags 3 are stacked on the second pipe section 102 along the inner and outer directions of the sleeve 1, with the bags 3 arranged around the second pipe section 102. The outermost bag 3 has an outer diameter less than or equal to the outer diameter of the first pipe section 101. The bags 3 are made of biodegradable materials and can degrade at high temperatures. The multiple bags 3 are used to fill sand-control materials with different filtration precisions, and the filtration precision of the sand-control materials in the multiple bags 3 gradually increases from the outside to the inside.

[0028] Multiple conveying pipes 4 correspond one-to-one with multiple bags 3. One end of the conveying pipe 4 is connected to the corresponding bag 3, and the other end of the conveying pipe 4 extends out of the first pipe section 101 through the sleeve 1. The conveying pipe 4 is used to convey sand control material into the bag 3.

[0029] In use, the chemical sand control device 100 of this invention first lowers the casing 1 into the oil well and places the second pipe section 102 in the oil-producing layer. After the casing 1 is lowered, sand control materials with different filtration accuracies are filled into each bag 3 using the feed pipe 4. The filtration accuracies of these sand control materials gradually increase from the outside to the inside, thereby ensuring effective sand filtration. After filling, high-temperature gas is supplied into the bags 3 through the feed pipe 4, causing the bags 3 to gradually degrade under high temperature. As the bags 3 degrade, the sand control material inside the bags 3 is fixed in the direction of the inside and outside of the casing 1, forming a stable sand control layer to filter sand in the oil.

[0030] The chemical sand control device 100 of this invention forms multiple sand control layers with different filtration precisions in the inner and outer directions of the casing 1 through the bag 3, effectively preventing sand particles in the oil layer from entering the casing 1, thereby protecting the wellbore and equipment and increasing oil well production. Compared with traditional multi-step, multi-equipment operations, this invention achieves the setting of multiple sand control layers through simple bag 3 filling and high-temperature gas transportation, greatly simplifying the operation process. The simplified operation reduces the demand for manpower and equipment, thereby reducing production costs. The bag 3 uses biodegradable materials, reducing environmental pollution. The degradation process is controllable, reducing potential safety risks during operation. By adjusting the type and precision of the sand control material inside the bag 3, it can adapt to the sand production conditions of different oil wells, improving the applicability of the device.

[0031] In some embodiments, the plurality of bags 3 include a first bag 301, a second bag 302, and a third bag 303 arranged sequentially from the outside in. The first bag 301 is used to fill a first sand-proof material 5, the second bag 302 is used to fill a second sand-proof material 6, and the third bag 303 is used to fill a third sand-proof material 7, wherein the first sand-proof material 5 forms a low-precision filter layer, the second sand-proof material 6 forms a medium-precision filter layer, and the third sand-proof material 7 forms a high-precision filter layer.

[0032] For example, such as Figure 1 and Figure 3 As shown, the sandbags 3 are arranged sequentially from the outside in, with the first sandbag 301 on the outermost side, followed by the second sandbag 302, and then the third sandbag 303. The first sandbag 301 is filled with a first sand-control material 5, which has a lower filtration precision and is used to initially intercept larger sand particles. The second sandbag 302 is filled with a second sand-control material 6, whose filtration precision is between that of the first and third sand-control materials 7, and is used to intercept medium-sized sand particles. The third sandbag 303 is filled with a third sand-control material 7, which has the highest filtration precision and is used to intercept smaller sand particles. In this way, the sandbags 3 form a sand-control layer structure consisting of a low-precision filtration layer, a medium-precision filtration layer, and a high-precision filtration layer in the direction inside and outside the casing 1. The arrangement of multiple layers of filtration with different precisions makes the sand-control effect more efficient, capable of intercepting sand particles of different sizes and reducing the impact of sand production on oil well production. Through effective sand control, the obstruction of sand particles to oil flow is reduced, and the oil well production is increased. The presence of a sand-control layer reduces the chance of sand particles entering the oil well equipment, thereby reducing equipment wear and maintenance frequency. Reduced sand production and its damage to the wellbore contribute to extending the well's service life.

[0033] Optionally, the first sand-proof material 5 is a mixture of sand, walnut shells and plastic granules, with the sand particles having a diameter of 4mm-8mm.

[0034] The first sand-control material 5 is a mixture comprising sand grains, walnut shells, and plastic granules. This mixture is designed to provide a material that is both effective in sand control and possesses suitable mechanical strength. The sand grains range in size from 4mm to 8mm, a size range generally large enough to intercept larger sand particles and prevent them from entering the well's production area. Walnut shells typically have high hardness and abrasion resistance; they can be included as part of the mixture to increase the mechanical strength and abrasion resistance of the sand-control layer. The plastic granules may help improve the flow properties of the mixture, and compared to some expensive sand-control materials, this mixture may be less expensive, helping to reduce the operating costs of the well.

[0035] Optionally, the second sand-blocking material 6 is a mixture of gravel, glass microspheres and synthetic resin particles, with the gravel having a particle size of 2mm-4mm.

[0036] The second sand control material 6 is a carefully designed mixture that combines the properties of gravel, glass microspheres, and synthetic resin particles (such as polyethylene) to provide moderate filtration precision and mechanical strength. The gravel has a particle size between 2mm and 4mm, a size range suitable for intercepting medium-sized sand particles while allowing smaller particles to pass through, thus achieving finer filtration. The second sand control material 6 provides moderate filtration precision, intercepting smaller sand particles that may still impact well production, while allowing some fine particles to pass through, reducing resistance to oil flow. Gravel and glass microspheres typically have high hardness and abrasion resistance, which helps improve the overall mechanical properties of the sand control layer and extend its service life. Synthetic resin particles may have good flow properties and filling characteristics, contributing to the uniform distribution of the mixture within the bag 3.

[0037] Optionally, the third sand-control material 7 is a mixture of quartz sand and ceramic particles, wherein the particle size of the quartz sand is in the range of 0.5 mm to 1.2 mm.

[0038] The third sand control material 7 combines the properties of quartz sand and ceramic particles. Both materials typically possess high hardness and stable chemical properties, making them suitable for fine filtration. The quartz sand particle size ranges from 0.5mm to 1.2mm, a size range ideal for intercepting finer sand particles, providing high-precision filtration. The third sand control material 7 can intercept very fine sand particles that could cause wear or blockage to downstream equipment; therefore, high-precision filtration is crucial for protecting equipment and maintaining well production. The use of quartz sand and ceramic particles increases the stability and durability of the sand control layer, helping to maintain sand control effectiveness over the long term. Due to its fine filtration performance, the third sand control material 7 reduces resistance to oil flow, thereby improving well production efficiency.

[0039] In some embodiments, the second section 102 of the sleeve 1 is designed with oil passage holes. These holes allow oil to flow through while preventing sand particles from entering. Multiple layers of stainless steel mesh 8 are filled within the oil passage holes. These mesh layers act as an additional filtration barrier, intercepting fine sand particles that have passed through the sand-proof layer. The multiple layers of stainless steel mesh 8 provide additional filtration capacity; even for extremely fine sand particles, it is difficult for them to pass through the stainless steel mesh 8, even with the sand-proof material layer, thereby further improving the sand-proof effect.

[0040] In some embodiments, the chemical sand control device 100 of the present invention further includes an oil pipe 9, one end of which extends into the second pipe section 102 of the casing 1, and the other end of which extends out of the first pipe section 101. A packer located in the second pipe section 102 is provided between the oil pipe 9 and the casing 1.

[0041] like Figures 1 to 3As shown, one end of the tubing 9 extends into the second section 102 of the casing 1, and the other end extends out of the first section 101. The tubing 9 is used to transport oil and gas from the well to the surface. The packer is located inside the second section 102 of the casing 1, between the tubing 9 and the casing 1. The main function of the packer is to isolate the space between the tubing 9 and the casing 1, preventing oil, gas, or sand control materials from entering unwanted areas. The presence of the packer effectively isolates the space between the tubing 9 and the casing 1, preventing sand control materials or other fluids from entering the tubing 9, thereby protecting the cleanliness and unobstructed flow of the oil transport channel.

[0042] In some embodiments, a screen pipe 10 is provided at the inlet end of the oil pipe 9, and the screen pipe 10 is coaxially arranged and connected to the oil pipe 9. The screen pipe 10 is located at the inlet end of the oil pipe 9, and is coaxially arranged with the oil pipe 9, that is, the center line of the screen pipe 10 is aligned with the center line of the oil pipe 9, and the screen pipe 10 is internally connected to the oil pipe 9. The screen pipe 10 further filters and prevents sand from entering the oil pipe 9. The screen pipe 10, in conjunction with multiple layers of sand prevention layers, forms a multi-stage filtration system, which improves the filtration efficiency and sand prevention effect of the entire sand prevention device.

[0043] In some embodiments, the capsule 3 is a thermoplastic starch capsule 3, and the pyrolysis temperature of the thermoplastic starch capsule 3 is 100℃-150℃.

[0044] Thermoplastic starch pouch 3 is a bag made of thermoplastic starch. This material can soften and become malleable within a certain temperature range, making it easy to fill and fix sand-proof material. The pyrolysis temperature of thermoplastic starch pouch 3 is set at 100℃-150℃. Within this temperature range, pouch 3 can undergo pyrolysis under the action of high-temperature gas, thereby releasing the filled sand-proof material and forming a sand-proof layer.

[0045] The thermoplastic starch bags 3 do not require complex chemical treatment during pyrolysis; high-temperature gas is simply transported through the feed pipe 4, making operation relatively simple. As a renewable material, thermoplastic starch has relatively low cost, helping to reduce the operating costs of oil wells. The thermoplastic starch bags 3 have a wide pyrolysis temperature range, which can be adjusted according to different oil well conditions and production needs, exhibiting good adaptability. Due to the controllable pyrolysis temperature, operators can precisely control the pyrolysis process of the bags 3, ensuring the effective release of sand-control materials and the formation of a sand-control layer.

[0046] The present invention also discloses a chemical sand control method, which is applied to the chemical sand control device 100 in any of the above embodiments, and includes the following steps:

[0047] S1. Lower casing 1 into the oil well and place the second section 102 of casing 1 into the oil-producing layer in the oil well;

[0048] S2. The third sand-proof material 7 is conveyed into the third bag 303, the second sand-proof material 6 is conveyed into the second bag 302, and the first sand-proof material 5 is conveyed into the first bag 301 through the conveying pipe 4.

[0049] S3. After the material is conveyed, high-temperature gas is sequentially conveyed into the first bag 301, the second bag 302 and the third bag 303 through the conveying pipe 4. The first bag 301, the second bag 302 and the third bag 303 are degraded under the action of the high-temperature gas, so that the sand-proof material filled in the first bag 301, the second bag 302 and the third bag 303 forms a multi-layer sand-proof layer in the direction of the inside and outside of the sleeve 1.

[0050] The chemical sand control method of this invention forms a multi-layered sand control layer in the casing 1 by sequentially filling sand control materials of different precisions and degrading the bag 3 under the action of high-temperature gas. This effectively intercepts sand particles of different sizes. The multi-layered sand control design improves sand control efficiency and reduces the impact of sand particles on oil well production. The entire sand control process is achieved through the delivery pipe 4 and the transport of high-temperature gas, simplifying operation and reducing complex steps and equipment requirements. The use of biodegradable bag 3 material reduces environmental impact, while the use of high-temperature gas improves energy efficiency. Simplified operation and the use of biodegradable materials help reduce the operating costs of oil wells. Through effective sand control measures, equipment wear and accident risks caused by sand particles are reduced, improving the production safety of oil wells.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A chemical sand control device, characterized in that, The application relates to a casing pipe (1) and an oil pipe (9) for oil extraction. The casing pipe (1) comprises a first pipe section (101) and a second pipe section (102) connected with each other, the outer diameter of the first pipe section (101) is larger than that of the second pipe section (102), and an oil passage is formed in the wall of the second pipe section (102). A sealing plate (2) is connected with the second pipe section (102) of the casing pipe (1) and seals the pipe opening of the second pipe section (102) away from the first pipe section (101). A plurality of bags (3) are arranged on the second pipe section (102) in the direction from the outside to the inside of the casing pipe (1), the bags (3) are arranged around the second pipe section (102) in a circle, the outer diameter of the outermost bag (3) is less than or equal to the outer diameter of the first pipe section (101), the bags (3) are made of degradable material and can be degraded at high temperature, the bags (3) are filled with different sand prevention materials with different filtering accuracies, and the filtering accuracy of the sand prevention materials in the bags (3) gradually increases in the direction from the outside to the inside. A plurality of feeding pipes (4) correspond to the bags (3) one by one, one end of the feeding pipe (4) communicates with the corresponding bag (3), and the other end of the feeding pipe (4) extends out of the first pipe section (101) through the casing pipe (1), and the feeding pipe (4) is used for conveying sand prevention materials into the bag (3).

2. The chemical sand control device of claim 1, wherein, The bags (3) comprise a first bag (301), a second bag (302) and a third bag (303) arranged in sequence from the outside to the inside, the first bag (301) is used for filling a first sand prevention material (5), the second bag (302) is used for filling a second sand prevention material (6), and the third bag (303) is used for filling a third sand prevention material (7), wherein the first sand prevention material (5) forms a low-accuracy filtering layer, the second sand prevention material (6) forms a medium-accuracy filtering layer, and the third sand prevention material (7) forms a high-accuracy filtering layer.

3. The chemical sand control device of claim 2, wherein, The first sand prevention material (5) is a mixture of sand particles, walnut shells and plastic particles, and the particle size of the sand particles is 4mm-8mm.

4. The chemical sand control device of claim 2, wherein, The second sand prevention material (6) is a mixture of gravel, glass beads and synthetic resin particles, and the particle size of the gravel is 2mm-4mm.

5. The chemical sand control device of claim 2, wherein, The third sand prevention material (7) is a mixture of quartz sand and ceramic particles, and the particle size of the quartz sand ranges from 0.5mm to 1.2mm.

6. The chemical sand control device of claim 2, wherein, A plurality of layers of stainless steel meshes (8) are filled in the oil passage.

7. The chemical sand control device of claim 2, wherein, The oil pipe (9) extends into the second pipe section (102) of the casing pipe (1) at one end and extends out of the first pipe section (101) at the other end, and a packer (10) is arranged between the casing pipe (1) and the oil pipe (9) in the second pipe section (102).

8. The chemical sand control device of claim 7, wherein, A screen pipe (11) is arranged at the inlet end of the oil pipe (9) and coaxially arranged with the oil pipe (9) and in communication with the oil pipe (9).

9. The chemical sand control device of claim 2, wherein, The bag (3) is a thermoplastic starch bag (3), and the pyrolysis temperature of the thermoplastic starch bag (3) is 60-90 DEG C.

10. A chemical sand control method, which is applied to the chemical sand control device according to any one of claims 2-9, characterized in that, The method comprises the following steps: S1, lowering the sleeve (1) to the oil well, and placing the second pipe section (102) of the sleeve (1) in the oil layer in the oil well; S2, sequentially conveying the third sand prevention material (7) into the third bag (303), the second sand prevention material (6) into the second bag (302), and the first sand prevention material (5) into the first bag (301) through the conveying pipe (4); S3, after the conveying is completed, conveying high-temperature gas into the first bag (301), the second bag (302) and the third bag (303) through the conveying pipe (4), and the first bag (301), the second bag (302) and the third bag (303) are degraded under the action of the high-temperature gas, so that the sand prevention materials filled in the first bag (301), the second bag (302) and the third bag (303) form a multi-layer sand prevention layer in the inside and outside directions of the sleeve (1).

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