Continuous injection paraffin control device and method

Abstract

The invention provides a continuous injection paraffin control device and method.The continuous injection paraffin control device comprises a ground injection device, an oil pipe hanging device and an underground chemical injection pipe string, the ground injection device comprises a chemical injection device and a pump truck injection device, outlets of the chemical injection device and the pump truck injection device are communicated with a wellhead, and an inlet of the oil pipe hanging device is communicated with the wellhead; an outlet of the oil pipe hanging device is communicated with an inlet of the underground chemical injection pipe string, an outlet of the underground chemical injection pipe string is communicated with an underground annulus, the underground chemical injection pipe string comprises a continuous injection oil pipe, and the continuous injection oil pipe is a continuous oil pipe with the outer diameter ranging from 25.4 mm to 50.8 mm. The small-size continuous injection oil pipe is arranged in the original well oil pipe, the paraffin inhibitor is sent to the specific depth of the oil pipe column through the small-size continuous injection oil pipe, the paraffin inhibitor reacts with the paraffin in the condensate oil, and the paraffin inhibition effect is achieved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, specifically to a continuous injection anti-wax device and method. Background Technology

[0002] Condensate gas reservoirs are a unique and complex type of gas reservoir characterized by high pressure and high wax content. The study of paraffin deposition is a major challenge in the exploitation of high-temperature, high-pressure, deep condensate gas reservoirs. In actual production, with the occurrence of wax deposition in different oil and gas fields, many wax removal and prevention technologies have been practically applied in the field.

[0003] Currently, chemical dewaxing and dewaxing technology is widely used in dewaxing and dewaxing techniques. Chinese patent CN206458415U, "Dewaxing and Dewaxing Completion String," provides a dewaxing and dewaxing completion string, including: tubing, a chemical injection valve, an injection line, and a controller. The chemical injection valve is used to connect or disconnect the tubing and the injection line. When the chemical injection valve is open, the tubing and the injection line are connected; when the chemical injection valve is closed, the tubing and the injection line are disconnected. The injection line is used to transmit the chemical dewaxing and dewaxing agent, and the controller is used to control the opening or closing of the chemical injection valve. This patent specifically employs an externally fixed capillary tube and chemical injection valve to inject a wax-removing agent using a surface chemical injection system. However, as actual production progresses, several challenging problems have emerged: ① The small capillary inner diameter (outer diameter 6.4mm, inner diameter 4.7mm) results in high pump friction (0-17000Psi) and high starting pressure (0-25000Psi), keeping the injection system under consistently high operating load and impacting its long-term serviceability; ② During low-flow-rate pumping, tool sealing is compromised, leading to wellhead pressure and posing a well control risk; ③ The injection flow rate is limited by the capillary inner diameter and pumping pressure, resulting in a relatively small flow rate, ranging from 0-45L / h, which is insufficient to address severe wax blockage in the wellbore. Therefore, a new process or technology is urgently needed to solve the current production challenges. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a continuous injection anti-wax device and method. A small-sized continuous injection tubing with an outer diameter ranging from 25.4 mm to 50.8 mm is installed in the original well tubing. The tubing is suspended at the wellhead, and a special pumping device is used at the surface to deliver the anti-wax agent to a specific depth in the tubing string through the tubing. The agent reacts with the wax in the condensate oil, achieving the anti-wax effect.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a continuous injection anti-wax device, comprising a surface injection device, a tubing suspension device, and a downhole chemical injection string. The surface injection device includes a chemical injection device and a pump truck injection device. The outlets of the chemical injection device and the pump truck injection device are connected to the wellhead. The inlet of the tubing suspension device is connected to the wellhead. The outlet of the tubing suspension device is connected to the inlet of the downhole chemical injection string. The outlet of the downhole chemical injection string is connected to the downhole annulus. The downhole chemical injection string includes a continuous injection tubing with an outer diameter of 25.4 mm to 50.8 mm.

[0006] Furthermore, the ground injection device includes a chemical injection device and a pump truck injection device. The chemical injection device includes a chemical agent injection pump, a ground check valve and a pump pipeline connected in sequence to achieve continuous injection of chemical agents under high pressure conditions. The chemical agent injection pump is a pneumatic booster pump with a displacement range of 0 to 100 L / h.

[0007] The pump truck injection device 2 includes a pump truck and a connecting pipeline connected in sequence. Both the pump injection pipeline and the connecting pipeline are connected to the wellhead. The pump truck has a displacement range of 0 to 600 L / h.

[0008] Furthermore, the upper flange of the tubing suspension device is the fluid inlet, and the lower flange is the fluid outlet. The upper flange is connected to the upper four-way valve, and the lower flange is connected to the lower wellhead. The tubing suspension device is equipped with bidirectional slips for suspending the downhole chemical injection string. The tubing suspension device and the suspended downhole chemical injection string are sealed through a metal main seal and a rubber secondary seal.

[0009] Furthermore, the downhole chemical injection string also includes a chemical injection string, the inlet of the continuous injection tubing is connected to the tubing suspension device, the outlet of the continuous injection tubing is connected to the inlet of the chemical injection string, and the outlet of the chemical injection string is connected to the downhole annulus.

[0010] Furthermore, the chemical injection string includes an external slip joint, an underground check valve, and a back pressure valve connected in sequence. The inlet of the chemical injection string is connected to the outlet of the continuous injection tubing through the external slip joint.

[0011] Furthermore, the underground check valve includes an upper connector, a first pin, a first sealing ring, a first valve tip, a second spring, a support plate, a second valve body, a second sealing ring, and a first sealing ring. The upper connector is connected to one end of the second valve body via the first pin. A first sealing ring is provided on the outer wall of one end of the upper connector for sealing connection with one end of the second valve body. A first valve tip is provided at the outlet of the internal channel of the upper connector, with the tip facing the internal channel of the upper connector. The bottom of the first valve tip is connected to one end of a second spring in the internal channel of the second valve body. The other end of the second spring is connected to the support plate, which is fixed in the internal channel of the second valve body. A second sealing ring and a first sealing ring are provided on the outer wall of the other end of the second valve body for sealing connection with a back pressure valve.

[0012] Furthermore, the back pressure valve includes a third valve body, a valve plate, a second valve tip, a third sealing ring, a valve seat, a third spring, a top seat, an adjusting rod, a second sealing ring, a second pin, a connecting body, a third pin, and a fourth sealing ring. The third valve body is connected to the connecting body via the second pin. A valve plate is installed at one end of the internal channel of the third valve body. One end of the second valve tip abuts against the valve plate channel, and the other end of the second valve tip abuts against one end of the valve seat. The valve seat is slidably connected to the internal channel of the third valve body. The other end of the valve seat is connected to one end of the third spring, and the other end of the third spring is connected to one end of the top seat. The other end of the top seat abuts against one end of the adjusting rod. The adjusting rod is fixed in the internal channel of the connecting body.

[0013] Furthermore, the ground-based one-way valve includes a first valve body, a sealing seat, a rubber seal, a cone seat, a first spring, a steel ring, a gland flange, a screw, a locking nut, an instrument, and a pressure relief port. The gland flange is fixed to the top of the first valve body by the steel ring, screw, and locking nut. The first valve body has an inlet and an outlet, and an installation cavity is provided inside the first valve body. This installation cavity is connected to both the inlet and the outlet. A sealing seat is provided inside the installation cavity near the inlet. A channel is provided on the sealing seat, which is connected to the inlet. The outlet of the channel on the sealing seat is in contact with the cone seat. The bottom of the cone seat is in contact with one end of the first spring, and the other end of the first spring is in contact with the inside of the gland flange.

[0014] Furthermore, the tubing suspension system and downhole chemical injection tubing are both made of corrosion-resistant alloys.

[0015] The present invention also provides a method for preventing wax deposition in high-wax gas wells, which uses the above-mentioned continuous injection anti-wax device, and the specific steps are as follows:

[0016] 1) When performing continuous pumping of wax-preventing agent in high wax-content gas wells, a chemical injection device is used to continuously pump the wax-preventing agent to achieve continuous pumping of wax-preventing agent and unblock the blockage;

[0017] 2) When a high-wax gas well is severely blocked by wax or has been shut down and reopened for a long time, a large-volume pump injection device is used to inject anti-wax agent to unblock it.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] This invention provides a continuous injection anti-wax device. By running a small-sized continuous injection tubing into the original well tubing, the original well string condition is not changed, thus maximizing the maintenance of wellbore integrity. Furthermore, the use of a small-sized continuous injection tubing for pumping anti-wax agent, with a fluid transmission inner diameter larger than that of a capillary tube, offers advantages such as low pumping friction (0-5000 Psi), low starting pressure (0-10000 Psi), and large injection displacement (0-600 L / h). In long-term service, it can minimize the operating load of the entire system, extend the system's operating cycle, and increase system operational safety.

[0020] This invention also includes a chemical injection device and a pump truck injection device to achieve continuous or intermittent pumping of anti-wax agent, which facilitates production management. The chemical injection device is mainly driven by a pneumatic booster pump, and the output pressure and flow rate can be adjusted in real time according to the working conditions. It can achieve continuous pumping of anti-wax agent under high pressure conditions and realize long-term stable production. The pump truck injection device mainly uses a pump truck for pumping, which has the characteristics of large displacement, realizing large-displacement positive circulation pumping of anti-wax agent. It can achieve intermittent pumping under high pressure conditions and can also solve the problem of wax blockage in the wellbore in a short time and restore wellbore production. Attached Figure Description

[0021] Figure 1 Structural principle diagram of the present invention;

[0022] Figure 2 Schematic diagram of the internal structure of the tubing suspension device;

[0023] Figure 3 Schematic diagram of the internal structure of a ground-based check valve;

[0024] Figure 4 Chemical injection string structure diagram;

[0025] Figure 5 Schematic diagram of an underground check valve;

[0026] Figure 6 Schematic diagram of the back pressure valve;

[0027] In the attached diagram: 1. Chemical injection device; 2. Pump truck injection device; 3. Tubing suspension device; 31. Metal main seal; 32. Rubber secondary seal; 33. Top screw; 34. Bidirectional slips; 35. Retrieval head; 4. Surface check valve; 41. First valve body; 42. Sealing seat; 43. Rubber sealing device; 44. Cone seat; 45. First spring; 46. Steel ring; 47. Pressure cap flange; 48. Screw; 49. Locking nut; 410. Instrument and pressure relief interface; 5. Tubing suspension device; 6. Downhole chemical injection string; 61. External slip joint; 62. Underground check valve; 63. Back pressure valve. ; 621 Upper connector, 622 First pin, 623 First sealing ring, 624 First valve tip, 625 Second spring, 626 Support plate, 627 Second valve body, 628 Second sealing ring, 629 First sealing ring; 631 Third valve body, 632 Valve plate, 633 Second valve tip, 634 Third sealing ring, 635 Valve seat, 636 Third spring, 637 Top seat, 638 Adjusting rod, 639 Second sealing ring, 6310 Second pin, 6311 Connector, 6312 Third pin, 6313 Fourth sealing ring. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 As shown, the present invention provides a continuous injection anti-wax device and method, the structure of which mainly includes a surface injection device, a tubing suspension device 3, and a downhole chemical injection string 6. The surface injection device includes a chemical injection device 1 and a pump truck injection device 2. The chemical injection device 1 consists of a chemical injection pump, a surface check valve 4, and a pumping pipeline. The chemical injection pump is driven by a pneumatic booster pump, and the output pressure and flow rate can be adjusted in real time according to the working conditions, enabling programmed pumping under high-pressure conditions. The surface check valve 4 can isolate pressure leakage under pumping conditions, ensuring the well control safety of the wellhead equipment. The chemical injection device 1 is mainly used for continuous injection anti-wax work under normal working conditions, with a discharge range of 0-100 L / h. The pump truck injection device 2 consists of a pump truck and connecting pipelines. Its pump outlet pipeline is connected to the left flange of the wellhead and is controlled by a stopcock and a flat valve. The discharge range is 0-600L / h. It is mainly used for wellbore protection work when a large-volume pump injection is needed to remove wax blockage or when the well is shut down and reopened for a long time. It is used to quickly solve the wax blockage situation in the wellbore.

[0030] like Figure 2 As shown, the tubing suspension device 3 is used for wellhead suspension, sealing, and well control of the downhole chemical injection string 6, and provides an injection channel for the anti-wax agent; the tubing suspension device 3 includes a metal main seal 31, a rubber secondary seal 32, a top screw 33, a two-way slip 34, and a retrieval head 35. The upper flange of the tubing suspension device 3 is the fluid inlet, and the lower flange is the fluid outlet. The upper flange is connected to the upper four-way valve, and the lower flange is connected to the lower wellhead.

[0031] The downhole chemical injection string 6 is lowered to the target depth using a dedicated downhole device and connected to the surface injection device via the tubing suspension device 3. The downhole chemical injection string 6 mainly consists of the continuous injection tubing 5 and the chemical injection string. Considering the long service life, the chemical injection string is made of corrosion-resistant stainless steel.

[0032] The continuous injection tubing 5 is a continuous tubing with an outer diameter of 25.4 to 50.8 mm. The tubing suspension device 3 is anchored to the continuous injection tubing 5 by bidirectional slips 34, which can effectively prevent the continuous injection tubing 5 from falling or rising. At the same time, the use of metal main seal 31 and rubber secondary seal 32 can effectively isolate the well fluid from the corrosion of bidirectional slips 34, ensuring the stability, safety and reliability of long-term service.

[0033] like Figure 4 As shown, the chemical injection tubing string includes an external slip connector 61, an underground check valve 62, and a back pressure valve 63. The chemical injection tubing string is connected to one end of the continuous injection tubing 5 via the external slip connector 61. The underground check valve 62 and the back pressure valve 63 are used to reverse flow and prevent the high-temperature and high-pressure fluid in the wellbore from invading the tool in reverse.

[0034] like Figure 5 As shown, the underground one-way valve 62 includes an upper connector 621, a first pin 622, a first sealing ring 623, a first valve tip 624, a second spring 625, a support plate 626, a second valve body 627, a second sealing ring 628, and a first sealing ring 629. The upper connector 621 is connected to one end of the second valve body 627 via the first pin 622. The outer wall of one end of the upper connector 621 is provided with a first sealing ring 623 for sealing connection with one end of the second valve body 627. The first valve tip 624 is provided at the outlet of the internal channel of the upper connector 621, with the tip facing the internal channel of the upper connector 621. The bottom of the first valve tip 624 is connected to one end of the second spring 625 in the internal channel of the second valve body 627. The other end of the second spring 625 is connected to the support plate 626, and the support plate 626 is fixed in the internal channel of the second valve body 627. The outer wall of the other end of the second valve body 627 is provided with a second sealing ring 628 and a first sealing ring 629 for sealing connection with the back pressure valve 63.

[0035] like Figure 6As shown, the back pressure valve 63 includes a third valve body 631, a valve plate 632, a second valve tip 633, a third sealing ring 634, a valve seat 635, a third spring 636, a top seat 637, an adjusting rod 638, a second sealing ring 639, a second pin 6310, a connecting body 6311, a third pin 6312, and a fourth sealing ring 6313. The third valve body 631 is connected to the connecting body 6311 via the second pin 6310. The valve plate 632 is installed at one end of the internal channel of the third valve body 631, and the second valve tip 639... One end of the valve tip 633 is abutted to the valve plate 632 channel, and the other end of the valve tip 633 is abutted to one end of the valve seat 635. The valve seat 635 is slidably connected to the internal channel of the third valve body 631. The other end of the valve seat 635 is connected to one end of the third spring 636. The other end of the third spring 636 is connected to one end of the top seat 637. The other end of the top seat 637 is abutted to one end of the adjusting rod 638. The adjusting rod 638 is fixed in the internal channel of the connecting body 6311. The adjusting rod is used to adjust the initial elastic force of the third spring 636 and set the pressure opening value.

[0036] The inner wall of the third valve body 631 is provided with a second sealing ring 639. The valve body 63 is sealed to the connecting body 6311 through the second sealing ring 639. The outer wall of the connecting body 6311 is provided with a third pin 6312 and a sealing ring 6313 for connecting to the next device.

[0037] like Figure 3 As shown, the ground flow valve 4 includes a first valve body 41, a sealing seat 42, a rubber seal 43, a cone seat 44, a first spring 45, a steel ring 46, a gland flange 47, a screw 48, a locking nut 49, and an instrument and pressure relief port 410. The gland flange 47 is fixed to the top of the first valve body 41 by the steel ring 46, the screw 48, and the locking nut 49. The first valve body 41 has an inlet and an outlet. The first valve body 41 has an installation cavity inside, which is connected to both the inlet and the outlet. The sealing seat 42 is installed inside the installation cavity near the inlet. A channel is opened on the sealing seat 42, which is connected to the inlet. The outlet of the channel on the sealing seat 42 is in contact with the cone seat 44. The bottom of the cone seat 44 is in contact with one end of the first spring 45, and the other end of the first spring 45 is in contact with the inside of the gland flange 47.

[0038] Preferably, the gland flange 47 is also provided with an instrument and pressure relief port 410;

[0039] Preferably, the outer wall of the sealing seat 42 is provided with a sealing rubber device 43 to ensure that the sealing seat 42 is sealed to the inner wall of the internal mounting cavity of the first valve body 41.

[0040] Preferably, all well-drilling tools are made of corrosion-resistant alloys, which can effectively ensure the long-term stability of the tool string under high temperature, high pressure and corrosion conditions.

[0041] The specific steps for using the continuous injection anti-wax device of the present invention are as follows:

[0042] S1. Well location selection: Select oil and gas wells with low temperature, low production, high wax content, easy wax blockage in the wellbore, and difficulty in ensuring continuous and stable oil and gas production as target wells.

[0043] S2. Lowering the continuous injection anti-wax device: Using coiled tubing equipment, lower the continuous injection anti-wax device to the target depth, and then... Figure 2 The bidirectional slips 34 in the tubing suspension device 3 suspend the continuous injection tubing 5, preventing it from shifting downwards or upwards, and then tighten them. Figure 2 Middle set screw 33, making Figure 2 The main metal seal 31 is activated to achieve sealing and to suspend the entire continuous injection device.

[0044] S3, Continuous pump injection anti-wax process

[0045] For high-wax oil and gas wells, it is necessary to adopt Figure 1 The chemical injection unit 1 prevents waxing by continuously pumping in an anti-wax agent. During the initial operation, first confirm the wellhead pressure, then start the chemical injection unit 1 to the corresponding pressure value and gradually increase the pressure. Figure 3 In the ground-level one-way valve 4, the cone seat 44 moves upward, opening the channel, and the chemical injection device 1 begins pumping the anti-wax agent into the tubing string. The anti-wax agent then passes through... Figure 1 4. Ground-level single-flow valve; 3. Oil pipe suspension device; 5. Continuous injection oil pipe. Figure 4 The middle and outer slip joint 61 reaches the underground check valve 62, when the pumping pressure reaches Figure 5 When the second spring 625 reaches its initial elastic force, the underground check valve 62 opens, and the anti-wax agent reaches the back pressure valve 63, continuing to pressurize. When the pumping pressure reaches the initial opening pressure set by the back pressure valve 63... Figure 6 When the third spring 636 is compressed, the valve seat 635 moves downward as a whole, the valve tip disengages from the valve seat, the channel opens, and the anti-wax agent enters the annulus from inside the tubing string to contact and react with the wax, thereby achieving the purpose of anti-wax. When the amount of pumped agent reaches the anti-wax requirement, the blowout or production process is gradually started to resume well production. At this time, the chemical injection rate can be adjusted to the economical rate in a timely manner according to the production and pressure fluctuations to ensure the long-term stable production of the equipment.

[0046] S4, Intermittent Pumping Dewaxing Process

[0047] For high-wax gas wells experiencing severe wax blockage or prolonged well shutdown and reopening, a large-volume injection of anti-wax agent is required to unblock the well. During the operation, first confirm the wellhead pressure, then start the pump truck to the corresponding pressure value, open the wellhead valve, and begin pumping the anti-wax agent into the tubing string. The anti-wax agent then... Figure 1 3-pipe suspension device, 5-pipe suspension device Figure 4 When the pump pressure reaches the check valve 62, the slip joint 61 reaches the check valve 62. Figure 5 When the second spring 625 reaches its initial elastic force, the check valve opens, and the anti-wax agent reaches the back pressure valve 63, continuing to pressurize. When the pumping pressure reaches the initial opening pressure set by the back pressure valve 63... Figure 6 When the third spring 636 is compressed, the valve seat 635 moves down as a whole, the valve tip disengages from the valve seat, the channel opens, and the anti-wax agent enters the annulus from inside the tubing string to contact and react with the wax, thereby achieving the purpose of wax removal. When the amount of pumped agent reaches the wax removal requirement, the blowout or production process is gradually started to restore wellbore production. At this time, the pumping can be stopped after judging that the wellbore is unobstructed based on the production and pressure fluctuation.

Claims

1. A continuous injection anti-wax device, characterized in that, It includes a surface injection device, a tubing suspension device (3), and a downhole chemical injection string (6). The surface injection device includes a chemical injection device (1) and a pump truck injection device (2). The outlets of the chemical injection device (1) and the pump truck injection device (2) are connected to the wellhead. The inlet of the tubing suspension device (3) is connected to the wellhead. The outlet of the tubing suspension device (3) is connected to the inlet of the downhole chemical injection string (6). The outlet of the downhole chemical injection string (6) is connected to the downhole annulus. The downhole chemical injection string (6) includes a continuous injection tubing (5). The continuous injection tubing (5) is a continuous tubing with an outer diameter of 25.4 mm to 50.8 mm.

2. The continuous injection anti-wax device according to claim 1, characterized in that, The ground injection device includes a chemical injection device (1) and a pump truck injection device (2). The chemical injection device (1) includes a chemical agent injection pump, a ground check valve (4) and a pump pipeline connected in sequence to realize the continuous injection of chemical agents under high pressure conditions. The chemical agent injection pump is a pneumatic booster pump with a displacement range of 0 to 100 L / h. The pump truck injection device 2 includes a pump truck and a connecting pipeline connected in sequence. Both the pumping pipeline and the connecting pipeline are connected to the wellhead. The pump truck's discharge range is 0 to 600 L / h.

3. The continuous injection anti-wax device according to claim 1, characterized in that, The upper flange of the tubing suspension device (3) is the fluid inlet, and the lower flange is the fluid outlet. The upper flange is connected to the upper four-way valve, and the lower flange is connected to the lower wellhead. The tubing suspension device (3) is equipped with bidirectional slips (34) for suspending the downhole chemical injection string (6). The tubing suspension device (3) and the suspended downhole chemical injection string (6) are sealed through the metal main seal (31) and the rubber secondary seal (32).

4. The continuous injection anti-wax device according to claim 1, characterized in that, The downhole chemical injection string (6) also includes a chemical injection string, the inlet of the continuous injection tubing (5) is connected to the tubing suspension device (3), the outlet of the continuous injection tubing (5) is connected to the inlet of the chemical injection string, and the outlet of the chemical injection string is connected to the downhole annulus.

5. The continuous injection anti-wax device according to claim 4, characterized in that, The chemical injection string includes an external slip joint (61), an underground check valve (62), and a back pressure valve (63) connected in sequence. The inlet of the chemical injection string is connected to the outlet of the continuous injection tubing (5) through the external slip joint (61).

6. The continuous injection anti-wax device according to claim 4, characterized in that, The underground one-way valve (62) includes an upper connector (621), a first pin (622), a first sealing ring (623), a first valve tip (624), a second spring (625), a support plate (626), a second valve body (627), a second sealing ring (628), and a first sealing ring (629). The upper connector (621) is connected to one end of the second valve body (627) via the first pin (622). A first sealing ring (623) is provided on the outer wall of one end of the upper connector (621) for sealing connection with one end of the second valve body (627). 621) A first valve tip (624) is provided at the outlet of the internal channel, with the tip facing the internal channel of the upper connector (621). The bottom of the first valve tip (624) is connected to one end of the second spring (625) in the internal channel of the second valve body (627). The other end of the second spring (625) is connected to the support plate (626). The support plate (626) is fixed in the internal channel of the second valve body (627). A second sealing ring (628) and a first sealing ring (629) are provided on the outer wall of the other end of the second valve body (627) for sealing connection with the back pressure valve (63).

7. A continuous injection anti-wax device according to claim 4, characterized in that, The back pressure valve (63) includes a third valve body (631), a valve plate (632), a second valve tip (633), a third sealing ring (634), a valve seat (635), a third spring (636), a top seat (637), an adjusting rod (638), a second sealing ring (639), a second pin (6310), a connecting body (6311), a third pin (6312), and a fourth sealing ring (6313). The third valve body (631) is connected to the connecting body (6311) via the second pin (6310). The internal passage of the third valve body (631) is... A valve plate (632) is provided at one end. One end of the second valve tip (633) is in contact with the channel of the valve plate (632), and the other end of the second valve tip (633) is in contact with one end of the valve seat (635). The valve seat (635) is slidably connected to the internal channel of the third valve body (631). The other end of the valve seat (635) is connected to one end of the third spring (636). The other end of the third spring (636) is connected to one end of the top seat (637). The other end of the top seat (637) is in contact with one end of the adjusting rod (638). The adjusting rod (638) is fixed in the internal channel of the connecting body (6311).

8. A continuous injection anti-wax device according to claim 2, characterized in that, The ground flow valve (4) includes a first valve body (41), a sealing seat (42), a rubber seal (43), a cone seat (44), a first spring (45), a steel ring (46), a gland flange (47), a screw (48), a locking nut (49), and an instrument and pressure relief port (410). The gland flange (47) is fixed to the top of the first valve body (41) by the steel ring (46), the screw (48), and the locking nut (49). The first valve body (41) has openings on it. The first valve body (41) has an installation cavity inside the inlet and outlet. The installation cavity is connected to both the inlet and outlet. An internal sealing seat (42) is provided at the end of the installation cavity near the inlet. A channel is opened on the sealing seat (42) and is connected to the inlet. The outlet of the channel on the sealing seat (42) is in contact with the cone seat (44). The bottom of the cone seat (44) is in contact with one end of the first spring (45). The other end of the first spring (45) is in contact with the inside of the gland flange (47).

9. A continuous injection anti-wax device according to claim 1, characterized in that, The tubing suspension device (3) and the downhole chemical injection string (6) are both made of corrosion-resistant alloy.

10. A method for preventing wax deposition in high-wax gas wells, characterized in that, The continuous injection anti-wax device according to any one of claims 1 to 9 is used, and the specific steps are as follows: 1) When continuously pumping wax-preventing agent into a high-wax gas well, a chemical injection device (1) is used to continuously pump wax-preventing agent to achieve continuous pumping wax prevention and unblocking. 2) When a high-wax gas well is severely blocked by wax or has been shut down and reopened for a long time, a pump truck injection device (2) is used to inject anti-wax agent in large volume to achieve unblocking.

Images