Dropping and fishing type paraffin control device and method for oil field exploitation

Abstract

The invention provides a throwing and fishing type paraffin control device and method for oil field exploitation, the throwing and fishing type paraffin control device comprises an eccentric working barrel and a throwing and fishing type valve body, both ends of the eccentric working barrel are connected with an oil pipe, a valve bag is arranged on the inner wall of one side of the eccentric working barrel, the throwing and fishing type valve body is installed in the valve bag, and a liquid inlet hole of the valve bag is communicated with a liquid inlet of the throwing and fishing type valve body; the throwing-fishing type valve body is filled with a solid paraffin inhibitor, and a plurality of slits are formed in the periphery of the throwing-fishing type valve body and used for blocking the solid paraffin inhibitor and sending the molten paraffin inhibitor into a shaft. The device is convenient to operate during use, high in safety and applicable to both oil wells and gas wells, well shaft smoothness in the production process can be kept to the maximum extent, and well shaft wax precipitation can be effectively prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield exploitation equipment, and in particular to a throwable and scoopable wax prevention device and method for oilfield exploitation. Background Art

[0002] According to statistics, crude oil with a wax content higher than 10% accounts for about 90% of the total crude oil production. When the well flow rises from the bottom of the well and flows through the wellbore, as the temperature and pressure gradually decrease, wax molecules gradually precipitate in the form of crystals and then continue to gather and accumulate on the pipe wall, resulting in wax deposition on the inner wall of the wellbore. Especially in oil and gas wells produced by self-flowing, wax deposition will seriously affect normal production. At present, the commonly used methods for wax removal and prevention include mechanical method, thermal method and chemical agent method. Among them, the mechanical method uses special working tools to scrape off the wax accumulated on the pipe wall. The removed wax flows to the ground with the fluid. The disadvantages of this method are that the device is easily damaged and the fixation is time-consuming and labor-intensive. The thermal method uses heat energy to increase the temperature of the oil flow and the oil pipe. When the temperature exceeds the wax precipitation temperature, it plays a role in preventing wax deposition. When the temperature exceeds the melting point of wax, it plays a role in wax removal. The disadvantages of this method are high cost and large limitations on well selection. The chemical agent method slows down and inhibits the formation of wax crystals by adding chemical agents to achieve the purpose of wax prevention. The injected chemical agents can dissolve paraffin to a certain extent to achieve the effect of wax removal. The commonly used chemical agent methods are solid wax prevention rods and chemical injection valves. After the solid wax prevention rod is put into the wellbore, as the wax prevention agent is partially dissolved, the remaining solid part is easy to accumulate at the action site, causing blockage to the wellbore. From a structural point of view, the chemical injection valve has the characteristics of high maintenance cost and high operation risk. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a throwable anti-wax device and method for oil field development, so as to achieve the purpose of maintaining the wellbore unobstructed during the production process to the greatest extent and effectively preventing wax deposition in the wellbore. The device is easy to operate and has high safety when used. It is not only applicable to oil wells and gas wells, but also will not cause blockage to the wellbore and wellhead.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a throwable anti-wax device for oil field development, comprising an eccentric working cylinder and a throwable valve body, both ends of the eccentric working cylinder are connected to the oil pipe, a valve bag is arranged on the inner wall of one side of the eccentric working cylinder, the throwable valve body is installed in the valve bag, the liquid inlet hole of the valve bag is connected with the liquid inlet port of the throwable valve body, the inside of the throwable valve body is filled with solid anti-wax agent, and a plurality of slits are arranged around the throwable valve body for blocking the solid anti-wax agent and delivering the melted anti-wax agent into the wellbore.

[0005] Furthermore, the outer diameter of the eccentric working cylinder is designed according to the size of the innermost casing at the wax protection position in the wellbore.

[0006] Furthermore, it also includes an inclined guide tube and an inclined guide groove. The inclined guide tube is connected to one end of the liquid inlet hole in the eccentric working cylinder away from the valve bag through a threaded fixing groove. The inclined guide groove is provided in the inclined guide tube to provide guidance when the casting and fishing valve body is lowered into the valve bag.

[0007] Furthermore, an installation opening is provided on one end of the valve bag away from the liquid inlet hole, and the cast-in-place valve body is lowered into the valve bag through the installation opening; two fixing devices are symmetrically provided on the inner wall of the valve bag, and the two fixing devices are used to fix the cast-in-place valve body lowered into the valve bag.

[0008] Furthermore, the fixing device includes a U-shaped block, a T-shaped block, a mounting groove and a support spring. The U-shaped block is fixed on the inner wall of the valve bag. The U-shaped block is provided with a socket. The movable end of the T-shaped block extends into the socket and is clamped on the bottom end of the U-shaped block on both sides of the socket. A mounting groove is provided on the side walls on both sides of the movable end of the T-shaped block. A support spring is provided in the mounting groove, and the other end of the support spring is connected to the inner wall of the valve bag.

[0009] Furthermore, the scooping valve body includes a scooping head, a cylinder, a slit, an annular base and a conical seat head. One end of the cylinder is connected to the scooping head. The inside of the cylinder is a hollow chamber for filling a solid wax inhibitor. The bottom end of the hollow chamber is an annular base evenly and densely covered with holes. The other end of the cylinder is connected to the conical seat head. The conical seat head is provided with a through hole connected to the hollow chamber, and the through hole is connected to the liquid inlet hole of the valve bag.

[0010] The present invention also provides a method for using a throwable wax prevention device for oil field development, and the specific steps are as follows:

[0011] S1 determines the type of solid wax inhibitor required to achieve the expected wax inhibitor effect, the amount K of solid wax inhibitor filled in a cast-in-place valve body, and the total amount N of solid wax inhibitor required in an operation cycle to obtain the number S of cast-in-place valve bodies required;

[0012] S2 designs the same number of eccentric working cylinders according to the number S of the required casting and fishing valve bodies. The eccentric working cylinders are connected by oil pipes and then lowered into the lower part of the wax deposition depth in the wellbore;

[0013] S3 fills S casting-type valve bodies with a solid anti-wax agent of K amount respectively, and lowers the S casting-type valve bodies into the valve bags of their corresponding eccentric working cylinders respectively. The well fluid enters the casting-type valve bodies to dissolve the solid anti-wax agent, and the well fluid containing the anti-wax agent enters the wellbore through the slits opened around the casting-type valve bodies.

[0014] Furthermore, in S1, the specific steps are as follows:

[0015] S1.1 Determine the type of solid wax inhibitor according to the type of well flow, and obtain the dissolution rate V of the solid wax inhibitor in the well flow by combining the relative atomic mass M of the solid wax inhibitor, the temperature T and pressure P corresponding to the depth of the solid wax inhibitor into the wellbore;

[0016] S1.2 Determine the wax prevention cycle J, obtain the ratio of the wax prevention cycle J to the dissolution rate V, and obtain the amount K of the solid wax prevention agent filled in a cast-in-place valve body;

[0017] S1.3 Determine the paraffin inhibitor concentration F corresponding to the expected paraffin inhibitor effect, and obtain the total amount N of solid paraffin inhibitor required in one operation cycle according to the paraffin inhibitor concentration F, the daily single well production Q of the production well, the paraffin inhibitor cycle J and the relative atomic mass M of the solid paraffin inhibitor;

[0018] S1.4 The required number S of the cast-in-place valve bodies is obtained based on the total amount N of the solid anti-wax agent required in one operation cycle and the amount K of the solid anti-wax agent filled in one cast-in-place valve body.

[0019] Furthermore, each eccentric working cylinder is arranged with an interval of 2 to 3 oil pipe lengths.

[0020] Furthermore, the solid wax inhibitor is a spherical solid wax inhibitor.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] The present invention provides a throwable anti-wax device for oil field development. An eccentric working cylinder is provided to dispose a throwable valve body filled with a solid anti-wax agent in an oil pipe, and a slit is provided on the throwable valve body to connect the throwable valve body with well fluid in the oil pipe. The well fluid enters the throwable valve body to dissolve the solid anti-wax agent and is brought into the well fluid in the oil pipe from the slit, thereby maintaining the smoothness of the wellbore during the production process to the greatest extent and effectively preventing wax deposition in the wellbore, and can reduce operation risks, consume less energy, and save costs.

[0023] The present invention fills the cast-in-place valve body with solid wax inhibitor to ensure that the wax inhibitor can be stored in the cast-in-place valve body and will not leak out like liquid or gas. Furthermore, the present invention adopts spherical solid wax inhibitor. When the spherical solid wax inhibitor is accumulated in the cast-in-place valve body, some gaps are left between the spherical solid wax inhibitors, ensuring that the external fluid has more contact area with the wax inhibitor after flowing into the cast-in-place valve body, thereby improving the release rate and effect of the wax inhibitor.

[0024] Compared with the instrument method, the wall thickness of the eccentric working cylinder used in the device of the present invention is not less than the thickness of the oil pipe, and both ends are connected to the oil pipe, so it can be lowered together with the oil pipe when the well starts to be put into production. In addition, the number of the dredging valve bodies in the eccentric working cylinder is limited and there are matching tools, which reduces the operation time and operation risk as a whole.

[0025] Compared with the thermal method, the present invention only needs to add anti-wax agent to the cast-in-place valve body, does not require electricity, has low energy consumption and low cost, and the size of the eccentric working cylinder is designed according to the size of the wellbore at the lowering depth, has low requirements on the well, and has a wide range of well selection conditions;

[0026] Compared with the chemical agent method, the solid wax inhibitor of the present invention can still exist in the casting and fishing valve body even if it is not fully dissolved, and will not enter the wellbore in a solid state to cause the wellbore to be blocked; BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the eccentric working cylinder;

[0028] Figure 2 It is a schematic diagram of the structure of the eccentric working cylinder;

[0029] Figure 3 It is a half-section schematic diagram of the cast-in-place valve body structure.

[0030] In the figure: 1. oil pipe; 2. guide tube; 3. guide groove; 4. eccentric working cylinder; 5. valve bag; 6. installation port; 7. U-shaped block; 8. T-shaped block; 9. installation groove; 10. support spring; 11. liquid inlet hole; 12. catching head; 13. cylinder; 14. slit; 15. annular base; 16. conical seat head. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the accompanying drawings so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments, and for those skilled in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, they are all protected.

[0032] The present invention provides a throwable wax prevention device for oilfield development, the main equipment of which is composed of an oil pipe 1, an eccentric working cylinder 4, and a throwable valve body. The outer diameter of the eccentric working cylinder 4 is designed according to the innermost casing size of the wellbore required to carry out wax prevention and the innermost casing size of the wellbore corresponding to the well depth. A valve bag 5 is arranged at one end of the inner wall of the eccentric working cylinder 4, and a mounting port 6 is arranged at one side of the valve bag 5. The required throwable valve body can be lowered into the valve bag 5 through the mounting port 6; U-shaped blocks 7 are symmetrically fixed on both sides of the inner wall of the valve bag 5, and a plug hole is arranged on the U-shaped block 7. The moving end of the T-shaped block 8 extends into the plug hole and is clamped at the bottom end of the U-shaped block 7 on both sides of the plug hole. A mounting groove 9 is arranged on the side walls on both sides of the moving end of the T-shaped block 8, and a support spring 10 is arranged in the mounting groove 9. The other end of the support spring 10 is connected to the inner wall of the valve bag 5.

[0033] A liquid inlet hole 11 is provided at the bottom of the valve bag 5 as a channel for the well fluid to flow into the valve bag 5 and the casting and fishing valve body.

[0034] Preferably, both ends of the eccentric working cylinder 4 are connected to the oil pipe 1 through threads, and a threaded fixing groove is provided in the eccentric working cylinder 4 at the connection point between one end of the eccentric working cylinder 4 and the oil pipe 1. The threaded fixing groove is connected to the guide pipe 2 through threads. The threaded connection can play a role in installing and fixing the guide pipe 2. An inclined guide groove 3 is provided in the guide pipe 2 as a guide for the required casting and catching valve body to be lowered.

[0035] Preferably, the dredging valve body includes a dredging head 12, a cylinder 13, a slit 14, an annular base 15 and a conical seat head 16. Specifically, the size of the dredging head 12 is designed with reference to the size of the dredging head used for the QJF-250D dredging gas lift valve for oil fields. A threaded male buckle is provided at one end of the dredging head 12, which is connected to a cylinder 13 with a female buckle on the top by a threaded connection. The cylinder 13 contains a hollow chamber with a diameter of A and a height of B. The hollow chamber is used to fill a certain number of spherical solid wax inhibitor particles with a diameter of E. The cylinder 13 is provided with a threaded male buckle at one end. There are multiple long strip slits 14 with a width of C and a length of D. The long strip slits 14 connect the hollow chamber in the cylinder 13 with the wellbore, providing a channel for the well fluid to flow into and out of the cylinder 13; the bottom of the cylinder 13 is an annular base 15 with holes evenly distributed; the bottom of the cylinder 13 is also provided with a female buckle, which is connected to the conical seat head 16 with a male buckle on the top by a threaded connection. The bottom of the conical seat head is provided with a conical chamfer, and the chamfer is evenly distributed with perforations around it. The bottom of the conical seat head 16 is designed to be located at the liquid inlet hole 11 at the lower end of the valve bag 5;

[0036] Preferably, the size of the liquid inlet hole 11 should match the bottom of the conical sealing head 16 to ensure that the well fluid can flow through the liquid inlet hole 11 through the perforations in the conical sealing head 16 into the hollow chamber to react with the solid wax inhibitor.

[0037] Preferably, the type and amount of the wax inhibitor of the present invention and the number of cast-and-fish valve bodies required are determined as follows:

[0038] 1) Select a paraffin inhibitor with better paraffin-proof effect according to the type of well flow, check the relative atomic mass M of the selected paraffin inhibitor, and test the dissolution rate V of the paraffin inhibitor in the well flow in combination with the temperature T and pressure P conditions corresponding to the required depth of the wellbore;

[0039] 2) According to the required anti-wax cycle J, combined with the formula J=K / V, the amount K of spherical solid anti-wax agent particles required to be placed in the chamber is calculated;

[0040] 3) According to the anti-wax agent concentration F corresponding to the expected anti-wax effect, combined with the daily single-well production Q of the production well and the required anti-wax operation cycle J, the total amount of anti-wax agent N required in one operation cycle is calculated according to the formula N = F × M × Q × J, and the number of plunge-and-dig valve bodies S required for design is obtained according to the formula S = N / K;

[0041] Wherein, V: dissolution rate of wax inhibitor, Kg / d; K: wax inhibitor dosage, Kg; J: wax inhibitor cycle, d; F: wax inhibitor concentration, mol / m 3 ; Q: single well production, m 3 / day; N: the total amount of anti-wax agent required in one operation cycle, kg; S: the number of cast-in-place valve bodies, pieces;

[0042] When the present invention uses the castable wax prevention device for oil field development, the eccentric working cylinder 4 is connected to the oil pipe 1 and lowered into the wellbore, and then the wax prevention agent is filled in all the hollow chambers, and the castable valve body is assembled, and then the castable valve body is installed by the running tool, and the castable valve body enters the eccentric working cylinder 4 through the inclined guide tube 2, and the castable valve body is inserted into the valve bag 5 through the installation mechanism;

[0043] Since the structure size of the catching head 12 of the catching valve body is designed with reference to the structure size of the catching head used in the QJF-250D catching gas lift valve for oil fields, the catching tool of the catching valve body of the present invention can be the same as that of the existing catching gas lift valve.

[0044] The cast-and-fish valve body moves in the valve bag 5 through the two T-shaped blocks 8, pushing the two T-shaped blocks 8 toward both ends, and the T-shaped blocks 8 slide in the jack, squeezing the support spring 10, and the support spring 10 is forced to shrink and deform until the bottom of the conical seating head 16 at the lower end of the cast-and-fish valve body is seated at the liquid inlet hole 11 at the lower end of the valve bag 5 to complete the fixation;

[0045] The well fluid flows through the liquid inlet hole 11 at the lower end of the valve bag 5, passes through the perforation at the chamfer of the conical seat head 16, and enters the hollow chamber. After fully contacting and taking effect with the solid wax inhibitor in the hollow chamber, the well fluid carrying the wax inhibitor flows out of the hollow chamber through the long strip cuts around the hollow chamber and flows into the oil pipe to mix with the new well fluid in the oil pipe, so that all the well fluids contain the wax inhibitor, thereby having an anti-wax effect on the well fluid in the oil pipe.

[0046] Example 1

[0047] like Figures 1 to 3As shown, a throwable anti-wax device is used in oil field development. Both sides of the eccentric working cylinder 4 are threadedly connected to the oil pipe 1. A fixed groove is processed on the left side of the eccentric working cylinder 4, and an inclined guide tube 2 is inserted into the fixed groove. A guide groove 3 is processed on the right side of the guide guide tube 2; a valve bag 5 is welded at one end of the inner wall of the eccentric working cylinder 4, and a mounting port is provided on the left side of the valve bag 5. Two U-shaped blocks 7 are symmetrically welded on the inner wall of the valve bag 5, each of which is processed with a perforation, and a T-shaped block 8 is inserted into the perforation. Both sides of the T-shaped block 8 extend into the U-shaped block 7, and mounting grooves 9 are processed on the two side walls respectively, and a support spring 10 is welded on the upper end surface of the mounting groove 9, and the support spring 10 is initially in an extended state; spherical solid anti-wax agent particles are installed in the hollow chamber of the throwable valve body, the throwable valve body is installed in the valve bag 5, and the well fluid flows into the throwable valve body to dissolve the anti-wax agent in the well fluid, thereby achieving an anti-wax effect.

[0048] The working principle of this embodiment is as follows:

[0049] A production well with a depth of H in a certain oil field is selected. Wax begins to form at the wellbore depth H1. The outer diameter of the oil pipe at the wax formation point is d1, and the inner diameter of the casing is d2. The outer diameter of the eccentric mandrel is designed to be d3 according to the size of the oil casing. In order to further ensure the smoothness of the production pipe string, a larger size can be designed when d3 is designed while ensuring that it can be normally lowered. Then, the number S of the cast-in-place valve bodies required to be lowered is calculated through the above steps (1) to (3), and the same number of eccentric mandrels 4 are designed. The spacing between each eccentric mandrel 4 can be set to be 2 to 3 oil pipe lengths. After the eccentric mandrels 4 are connected by oil pipes, they are lowered to the lower part of the wax formation depth H1 in the wellbore.

[0050] After indoor experiments, an oil-based anti-wax agent is selected. The anti-wax agent is then made into spherical solid anti-wax agent particles and loaded into the hollow chamber of the cast-in-place valve body. After the assembly is completed, the cast-in-place valve body is lowered into the wellbore for installation. The cast-in-place valve body enters the eccentric working cylinder 4 through the inclined guide tube 2, and the cast-in-place valve body is inserted into the valve bag 5 through the installation mechanism. The cast-in-place valve body moves in the valve bag 5 through between the two T-shaped blocks 8, and the two T-shaped blocks 8 are pushed toward both ends to squeeze the support spring 10 to cause it to shrink and deform under force. When the cast-in-place valve body slides to the bottom of the valve bag 5, the conical seat head 16 of the cast-in-place valve body is connected to the liquid inlet hole 11 of the valve bag 5, and the well fluid passes through the liquid inlet hole 11 on the valve bag 5. After flowing through the perforation of the conical seat head 16, the liquid enters the hollow chamber through the annular base 15 and reacts with the anti-wax agent in the hollow chamber. At the same time, the two T-shaped blocks 7 squeeze and fix the cast-and-fish valve body through the extension and rebound of the support spring, thereby strengthening the fixing effect of the cast-and-fish valve body in the valve bag 5. After the well fluid reacts with the anti-wax agent in the hollow chamber, a certain amount of the anti-wax agent will be carried in the well fluid, which flows through the long strip slits 14 around the hollow chamber and enters the wellbore to mix with the well fluid in the wellbore, thereby having an anti-wax effect on the well fluid in the wellbore. When the anti-wax period J is reached, the cast-and-fish valve body can be salvaged by a salvaging tool, and the solid anti-wax particles can be refilled in the hollow chamber and then lowered into the wellbore.

Claims

1. A throwable wax prevention device for oil field development, characterized in that: The invention comprises an eccentric working cylinder (4) and a cast-in-place valve body, wherein both ends of the eccentric working cylinder (4) are connected to an oil pipe (1), a valve bag (5) is arranged on the inner wall of one side of the eccentric working cylinder (4), the cast-in-place valve body is installed on the valve bag (5), a liquid inlet hole (11) of the valve bag (5) is connected to a liquid inlet of the cast-in-place valve body, a solid wax inhibitor is filled inside the cast-in-place valve body, and a plurality of slits (14) are arranged around the cast-in-place valve body for blocking the solid wax inhibitor and delivering the melted wax inhibitor into the wellbore.

2. The throwable and salvageable wax prevention device for oil field development according to claim 1, characterized in that: The outer diameter of the eccentric working cylinder (4) is designed according to the size of the innermost casing at the wax protection position in the wellbore.

3. The throwable and salvageable wax prevention device for oil field development according to claim 1, characterized in that: The invention also comprises an inclined guide tube (2) and an inclined guide groove (3). The inclined guide tube (2) is connected to one end of the liquid inlet hole (11) in the eccentric working cylinder (4) away from the valve bag (5) through a threaded fixing groove. The inclined guide groove (3) is provided in the inclined guide tube (2) for providing guidance when the cast-in-place valve body is lowered into the valve bag (5).

4. The throwable and salvageable wax prevention device for oil field development according to claim 1, characterized in that: An installation opening (6) is provided on one end of the valve bag (5) away from the liquid inlet hole (11), and the cast-in-place valve body is lowered into the valve bag (5) through the installation opening (6); two fixing devices are symmetrically provided on the inner wall of the valve bag (5), and the two fixing devices are used to fix the cast-in-place valve body lowered into the valve bag (5).

5. The throwable and salvageable wax prevention device for oil field development according to claim 4, characterized in that: The fixing device comprises a U-shaped block (7), a T-shaped block (8), a mounting groove (9) and a support spring (10). The U-shaped block (7) is fixed on the inner wall of the valve bag (5). The U-shaped block (7) is provided with a plug hole. The movable end of the T-shaped block (8) extends into the plug hole and is clamped at the bottom of the U-shaped block (7) on both sides of the plug hole. A mounting groove (9) is provided on both side walls of the movable end of the T-shaped block (8). A support spring (10) is provided in the mounting groove (9). The other end of the support spring (10) is connected to the inner wall of the valve bag (5).

6. The throwable and salvageable wax prevention device for oil field development according to claim 1, characterized in that: The dredging valve body comprises a dredging head (12), a cylinder (13), a slit (14), an annular base (15) and a conical seat seal (16). One end of the cylinder (13) is connected to the dredging head (12). The cylinder (13) contains a hollow chamber for filling a solid wax inhibitor. The bottom end of the hollow chamber is an annular base (15) uniformly and densely covered with holes. The other end of the cylinder (13) is connected to the conical seat seal (16). The conical seat seal (16) is provided with a through hole communicating with the hollow chamber. The through hole is communicated with the liquid inlet (11) of the valve bag (5).

7. A method for using a castable wax prevention device for oil field development according to any one of claims 1 to 6, characterized in that: The specific steps are as follows: S1 determines the type of solid wax inhibitor required to achieve the expected wax inhibitor effect, the amount K of solid wax inhibitor filled in a cast-in-place valve body, and the total amount N of solid wax inhibitor required in an operation cycle to obtain the number S of cast-in-place valve bodies required; S2 designs the same number of eccentric working cylinders (4) according to the number S of the required casting-and-fishing type valve bodies, and the eccentric working cylinders (4) are connected by oil pipes (1) and then lowered into the lower part of the wax deposition depth in the wellbore; S3 fills a solid wax inhibitor in an amount of K into each of the S casting-type valve bodies, and lowers the S casting-type valve bodies into the valve bags (5) of their corresponding eccentric working cylinders (4). Well fluid enters the casting-type valve bodies to dissolve the solid wax inhibitor, and the well fluid containing the wax inhibitor enters the wellbore through the slits (14) provided around the casting-type valve bodies.

8. The method for using the castable wax prevention device for oil field development according to claim 7, characterized in that: In S1, the specific steps are as follows: S1.1 Determine the type of solid wax inhibitor according to the type of well flow, and obtain the dissolution rate V of the solid wax inhibitor in the well flow by combining the relative atomic mass M of the solid wax inhibitor, the temperature T and pressure P corresponding to the depth of the solid wax inhibitor into the wellbore; S1.2 Determine the wax prevention cycle J, obtain the ratio of the wax prevention cycle J to the dissolution rate V, and obtain the amount K of the solid wax prevention agent filled in a cast-in-place valve body; S1.3 Determine the paraffin inhibitor concentration F corresponding to the expected paraffin inhibitor effect, and obtain the total amount N of solid paraffin inhibitor required in one operation cycle according to the paraffin inhibitor concentration F, the daily single well production Q of the production well, the paraffin inhibitor cycle J and the relative atomic mass M of the solid paraffin inhibitor; S1.4 The required number S of the cast-in-place valve bodies is obtained based on the total amount N of the solid anti-wax agent required in one operation cycle and the amount K of the solid anti-wax agent filled in one cast-in-place valve body.

9. The method for using the castable wax prevention device for oil field development according to claim 7, characterized in that: Each eccentric working cylinder (4) is arranged at intervals of 2 to 3 oil pipe lengths.

10. The method for using the castable wax prevention device for oil field development according to claim 7, characterized in that: The solid wax inhibitor is a spherical solid wax inhibitor.

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