Grease injection valve and grease injection method thereof

Abstract

The invention discloses a grease injection valve and a grease injection method thereof, and belongs to the technical field of grease injection valves.The grease injection valve comprises a valve body and a valve element and further comprises a nut, a grease injection hole penetrating the valve body along the axis of the valve body is formed in the valve body, and the grease injection hole comprises a movable section, a grease injection section and a containing channel which are sequentially communicated; the valve element comprises a plugging part and a straight rod part which are fixedly arranged, the plugging part is located in the movable section and used for opening and closing an opening in one end of the grease injection section, one end of the straight rod part extends into the containing channel, and the valve body is provided with a limiting piece for limiting the valve element to rotate around the axis of the valve element; the nut is located in the containing channel and matched with the straight rod part in a threaded mode. The nut is provided with a grease inlet hole which penetrates along the axis of the nut and is communicated with the grease injection section. The grease injection valve has the advantages that stable sealing of the valve body can be achieved conveniently, the grease injection valve can effectively cut off pressure in a well, a grease injection tool at the rear end of the grease injection valve can be detached conveniently, the original state of a wellhead device can be recovered, and it is guaranteed that grease injection operation is conducted safely and smoothly.

Description

Technical Field

[0001] This invention relates to the field of grease injection valves, and in particular to a grease injection valve and a grease injection method thereof. Background Technology

[0002] The grease injection valve is an accessory on natural gas wellhead equipment, installed on valves, conversion flanges, casing heads, or tubing heads. It is the last line of defense in isolating high-pressure natural gas downhole. During production operation, grease needs to be periodically injected into the relevant sealing parts of the wellhead equipment through the grease injection valve to ensure the long-term effective operation of the wellhead equipment. Failure to inject grease in a timely manner will shorten the effective life of the wellhead equipment and easily cause internal or external leakage of high-pressure natural gas in the well.

[0003] Currently, most grease injection valves used in the industry are simple one-way valve structures, such as... Figure 1 As shown, the valve mainly consists of a pin 1, a spring 2, a sealing steel ball 3, a valve body 4, and a nut 5. The valve relies on the spring 2 to push the sealing steel ball 3 back to its seat, forming a seal with the conical surface of the inner bore of the valve body 4. The left end of the valve body 4 is threadedly connected to and sealed with the body of the relevant components of the wellhead device. During grease injection, the grease injection tool is connected after removing the nut 5 to inject grease into the valve.

[0004] However, after the sealing grease is injected, the relevant body cavity of the wellhead device is filled with sealing grease. Due to the structural characteristics of this type of grease injection valve and the relatively viscous nature of the sealing grease used in the wellhead device, the sealing steel ball 3 often has difficulty overcoming the resistance and returning to its normal position under the action of spring force after grease injection. Once the seal between the steel ball and the valve body fails, the grease injection valve cannot effectively isolate the pressure in the well, which means that the grease injection tool at the rear end of the grease injection valve cannot be removed, and the original state of the wellhead device cannot be restored, affecting the normal and safe operation of subsequent production. Summary of the Invention

[0005] In order to facilitate a stable seal on the valve body, enable the grease injection valve to effectively isolate the pressure inside the well, facilitate the removal of the grease injection tool at the rear end of the grease injection valve, restore the original state of the wellhead device, and ensure the safe and smooth progress of grease injection operations, this application provides a grease injection valve and a grease injection method thereof.

[0006] In the first aspect, this application provides a grease injection valve, which adopts the following technical solution: A grease injection valve includes a valve body and a valve core, and also includes a nut. The valve body has a grease injection hole that extends along its own axis. The grease injection hole includes a movable section, a grease injection section, and a receiving channel that are sequentially connected. The valve core includes a fixedly disposed blocking part and a straight rod part. The blocking part is located in the movable section and is used to open and close one end of the grease injection section. One end of the straight rod part extends into the receiving channel. The valve body is provided with a limiting member to restrict the rotation of the valve core around its own axis. The nut is located in the receiving channel and is threadedly engaged with the straight rod part. The nut has a grease inlet hole that extends along its own axis and communicates with the grease injection section.

[0007] By adopting the above technical solution, when the nut is rotated, the limiting component restricts the rotation of the valve core, thereby converting the rotational motion of the nut into the linear motion of the valve core. This, in turn, drives the sealing part away from or presses against the opening of the grease injection section, realizing the opening and closing of the grease injection section. The method of actively and precisely controlling the valve core's movement by rotating the nut to open and close the grease injection section ensures that even with the resistance of viscous sealing grease, the operator can reliably close the valve, achieving a stable seal on the valve body. This allows the grease injection valve to effectively isolate the pressure inside the well, facilitating the removal of the grease injection tools at the rear of the valve, restoring the wellhead equipment to its original state, and ensuring the safe and smooth operation of grease injection.

[0008] Optionally, the receiving channel includes a connecting section and a receiving section. One end of the connecting section is connected to the grease injection section and the other end is connected to the receiving section. The inner diameter of the connecting section is larger than the inner diameter of the grease injection section and smaller than the inner diameter of the receiving section. The nut is located inside the receiving section, and the grease inlet hole is connected to the connecting section.

[0009] By adopting the above technical solution, the internal space layout of the valve body is optimized, ensuring the reliable realization of the function. The larger diameter receiving section provides ample space for the nut and its rotation operation without interference. The connecting section serves as a transition area, which facilitates the smooth flow of sealing grease from the nut grease inlet into the grease injection section, reducing flow resistance and turbulence.

[0010] Optionally, it also includes a grease injection spring and a pin, wherein the pin is mounted on the valve body and is arranged perpendicular to the valve body axis, the pin is located in the movable section, the grease injection spring is located between the pin and the sealing part, and the grease injection spring applies a spring force to the sealing part in the direction of the grease injection section.

[0011] By adopting the above technical solution, the setting of the grease injection spring provides redundant safety protection and assists the valve core. Under normal working conditions, the elasticity of the grease injection spring facilitates the closing action of the valve core and ensures that the sealing surface fits tightly. In extreme cases, such as when the nut drive fails, the elasticity of the grease injection spring can still push the valve core to achieve basic sealing and prevent the well pressure from running out of control.

[0012] Optionally, the end of the sealing part near the grease injection section is provided with a sealing cone surface, and the side of the grease injection section near the sealing part is provided with a sealing concave surface that corresponds to the sealing cone surface and is adapted in shape.

[0013] By adopting the above technical solution, the conical seal has excellent centering. When the sealing conical surface of the valve core is pressed into the sealing concave surface of the grease injection section under the action of nut drive or spring force, a tight and uniform sealing band is formed. The higher the pressure in the well, the more reliable the sealing effect, which is conducive to fully ensuring the sealing stability of the plugging part.

[0014] Optionally, the limiting component includes a limiting strip fixedly installed on the outside of the sealing part, and the side wall of the movable section is provided with a limiting groove extending along the axis of the valve body, and the limiting strip slides and engages in the limiting groove.

[0015] By adopting the above technical solution, the cooperation between the limiting strip and the limiting groove facilitates the stable guiding effect on the axial movement of the valve core, ensuring that the rotational torque of the nut can be stably converted into the linear driving force of the valve core, thereby achieving precise and controllable operation of the valve opening.

[0016] Optionally, it also includes a grease injection connector, which includes a connector nut, a central tube, a pressure cap, and a threaded sleeve. The connector nut is threadedly engaged with the valve body. The central tube passes through and is movably engaged with the connector nut. The threaded sleeve is fitted onto and threadedly engaged with the central tube. The pressure cap is threadedly engaged with the end of the connector nut away from the valve body. The threaded sleeve is located between the connector nut and the pressure cap. The nut has a rectangular groove on the side near the connector nut. One end of the central tube has an insertion protrusion that matches the shape of the rectangular groove and engages with it.

[0017] By adopting the above technical solution, when rotating the pressure cap, the pressure cap drives the central tube to move axially by pushing the threaded sleeve. When the insertion protrusion at the end of the central tube is inserted into the rectangular groove of the grease injection valve nut, a reliable torque transmission path is established. At this time, the nut can be directly driven to rotate forward or backward by rotating the central tube, and finally the opening and closing of the downhole valve core can be remotely controlled. The setting of the grease injection joint facilitates the stable docking and active control of grease injection operations, and has strong applicability.

[0018] Optionally, the central pipe thread is fitted with two caps, and the two caps are tightly fitted together.

[0019] By adopting the above technical solution, the setting of the two caps provides a reliable and non-loosening force application point for the rotation operation of the central tube. At the same time, it can effectively prevent the loosening or displacement of a single force application point when the central tube is rotated repeatedly in the forward and reverse directions to transmit torque, ensuring accurate, reliable and stable operation of the opening and closing of the downhole grease injection valve.

[0020] Optionally, a sealing ring is installed on the inner wall of the connector nut, and the sealing ring abuts against the outer wall of the central tube.

[0021] By adopting the above technical solution, when the grease injection connector is connected to the grease injection valve and high-pressure sealing grease is injected, the sealing ring is designed to effectively seal the gap between the central tube and the inner hole of the connector nut, preventing high-pressure grease leakage or spraying, ensuring operational safety, and avoiding media loss.

[0022] Optionally, a valve body indicator is provided on the outer peripheral surface of the valve body, and each side of the valve body indicator is parallel to the wall of the rectangular groove; a connector indicator is fixedly provided on the central tube, and the connector indicator has a connector indicator side parallel to each side of the insertion protrusion.

[0023] By adopting the above technical solution, when connecting the grease injection connector, the operator does not need to look inside. He only needs to rotate the center tube on the outside to align the indicator edge of the connector indicator with the corresponding edge of the valve body indicator. This ensures that the internal insertion protrusion and the rectangular groove are aligned in the circumferential direction, which helps to improve the docking efficiency of the grease injection connector and the valve body and avoids damage to parts caused by repeated trial and error.

[0024] Secondly, this application also provides a grease injection method based on the aforementioned grease injection valve, comprising the following steps: S1, removing the sealing nut of the valve body and connecting the grease injection connector to the valve body, specifically, connecting the connector nut of the grease injection connector to the valve body threadedly; S2, connecting the end of the grease injection connector away from the valve body to a grease injection tool; S3, operating the grease injection connector to open the grease injection valve; S31, screwing in the pressure cap, the pressure cap driving the central tube axially by pushing the threaded sleeve; S32, when the screwing force is obstructed, the central tube is rotated by applying force through one of the caps, cooperating with the screwing in of the pressure cap, so that the insertion protrusion of the central tube is inserted into the rectangular groove of the nut; S33, continuing to rotate the central tube by applying force through one of the caps, at this time, the sealing part of the valve core moves away from the valve body. S4. The nut moves in the direction of movement, thereby opening the grease injection valve; S5. Grease is injected into the wellhead device through the grease injection tool. The sealing grease flows from the grease injection tool through the inner hole of the central tube, the grease inlet hole of the nut, and the grease injection hole, i.e., the annular channel between the valve body and the valve core, into the wellhead device; S6. After the grease injection volume is completed, the grease injection ends; S7. The central tube is rotated in the opposite direction by applying force through another cap. At this time, the sealing part of the valve core moves towards the nut. When the sealing cone surface and the sealing concave surface are pressed together, the grease injection valve is closed; S8. The grease injection tool is removed; S9. The pressure cap is loosened, and force is applied to move the central tube axially away from the valve body, so that the insertion protrusion of the central tube disengages from the rectangular groove of the nut; S10. The connector nut is loosened, the grease injection connector is removed, and the sealing nut is installed on the valve body.

[0025] By adopting the above technical solution, the rotating nut is rotated through the grease injection connector, which allows the rotating nut to actively and precisely control the movement of the valve core to open and close the grease injection section opening. This ensures that even under the resistance of viscous sealing grease, the operator can reliably close the valve, achieving a stable seal on the valve body. Consequently, the grease injection valve can effectively isolate the pressure inside the well, facilitating the removal of the grease injection tools at the rear end of the grease injection valve, restoring the wellhead device to its original state, and ensuring the safe and smooth progress of grease injection operations.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The method of actively and precisely controlling the movement of the valve core by rotating the nut to open and close the grease injection section ensures that even under the resistance of viscous sealing grease, the operator can reliably close the valve and achieve a stable seal on the valve body. This allows the grease injection valve to effectively isolate the pressure inside the well, facilitates the removal of the grease injection tools at the rear end of the grease injection valve, restores the original state of the wellhead device, and ensures the safe and smooth progress of grease injection operations.

[0027] 2. The larger diameter receiving section provides ample and less interference-prone space for the nut and its rotation operation. The connecting section serves as a transition area, ensuring that the sealing grease flowing out of the nut's grease inlet smoothly merges into the grease injection channel, reducing flow resistance and turbulence.

[0028] 3. The nut can be directly driven to rotate forward or backward by rotating the central tube, and the opening and closing of the downhole valve core can be remotely controlled. The setting of the grease injection joint facilitates the stable connection and active control of grease injection operations, and has strong applicability. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the grease injection valve in the background art of this application.

[0030] Figure 2 This is a schematic diagram of the grease injection valve in Embodiment 1 of this application.

[0031] Figure 3 yes Figure 2 Schematic diagram of cross section AA.

[0032] Figure 4 This is a schematic diagram of the grease injection connector in Embodiment 1 of this application.

[0033] Figure 5 This is a schematic diagram showing the connection relationship between the grease injection valve and the grease injection connector in Embodiment 1 of this application.

[0034] Figure 6 This is a schematic diagram showing the connection relationship between the grease injection valve and the grease injection connector in Embodiment 2 of this application.

[0035] Explanation of reference numerals in the attached figures: 01. Pin; 02. Spring; 03. Sealing steel ball; 04. Valve body; 05. Nut; 1. Valve body; 2. Valve core; 201. Sealing part; 202. Straight rod part; 3. Nut; 4. Grease injection spring; 5. Pin; 6. Sealing nut; 7. Grease injection hole; 71. Moving section; 72. Grease injection section; 73. Receiving channel; 731. Connecting section; 732. Receiving section; 8. Sealing protrusion; 9. Inner conical surface; 10. Sealing conical surface; 11. Sealing concave surface; 12. Limiting strip ; 13. Limiting groove; 14. Grease inlet hole; 15. Grease injection connector; 151. Connector nut; 152. Center tube; 153. Pressure cap; 154. Threaded sleeve; 16. Connector conical surface; 17. Sealing ring; 18. Accommodating movable hole; 19. Connector movable groove; 20. Rectangular groove; 21. Insertion protrusion; 22. Connecting cap; 23. Connector screw plug; 24. Limiting screw sleeve; 25. Connector accommodating hole; 26. Valve body indicator; 27. Connector indicator element; 271. Connector indicator edge. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0037] This application discloses a grease injection valve and a grease injection method thereof. Example 1

[0038] Reference Figure 2 The grease injection valve includes a valve body 1, a valve core 2, a nut 3, a grease injection spring 4, a pin 5, and a sealing nut 6. The valve body 1 has a grease injection hole 7 extending along its own axis. The sealing nut 6 is threaded onto one end of the valve body 1 and seals the grease injection hole 7. To ensure a tight seal when the sealing nut 6 closes the grease injection hole 7, a sealing protrusion 8 is provided inside the sealing nut 6. The sealing protrusion 8 is circular with a beveled edge. An inner conical surface 9 is provided at the end of the valve body 1 near the sealing nut 6. The inner conical surface 9 engages with the beveled edge of the sealing protrusion 8 to ensure a stable seal of the grease injection hole 7 by the sealing nut 6.

[0039] Continue to refer to Figure 2Specifically, the grease injection hole 7 includes a movable section 71, a grease injection section 72, and a receiving channel 73 sequentially connected from one end of the valve body 1 away from the sealing nut 6 to the other end. The valve core 2 includes an integrally fixed sealing part 201 and a straight rod part 202. The sealing part 201 is located in the movable section 71 and is used to open and close one end of the grease injection section 72. To ensure the stability of the sealing part 201 when closing the opening of the grease injection section 72, a sealing cone surface 10 is provided at one end of the sealing part 201 near the grease injection section 72, and a sealing concave surface 11 corresponding to and adapted in shape to the sealing cone surface 10 is provided on the side of the grease injection section 72 near the sealing part 201. The cooperation between the sealing cone surface 10 and the sealing concave surface 11 helps to fully ensure the sealing stability of the sealing part 201 to the grease injection section 72.

[0040] One end of the straight rod 202 extends into the receiving channel 73. Specifically, the receiving channel 73 includes a connecting section 731 and a receiving section 732. One end of the connecting section 731 is connected to the grease injection section 72, and the other end is connected to the receiving section 732. The inner diameter of the connecting section 731 is larger than the inner diameter of the grease injection section 72 and smaller than the inner diameter of the receiving section 732, so that the sealing grease can flow smoothly into the grease injection section 72 and reduce flow resistance and turbulence.

[0041] Reference Figure 2 and Figure 3 The valve body 1 is provided with a limiting member to restrict the valve core 2 from rotating around its own axis. In this embodiment, the limiting member includes two limiting strips 12 fixedly installed on the outside of the sealing part 201. The side wall of the movable section 71 is provided with two limiting grooves 13 corresponding to the limiting strips 12 and extending along the axis of the valve body 1. The limiting grooves 13 penetrate the movable section 71. The two limiting strips 12 are respectively slidably engaged in the two limiting grooves 13 to restrict the rotation of the valve core 2 and play a stable guiding role when the valve core 2 moves axially.

[0042] Reference Figure 2 The nut 3 is located in the receiving section 732 of the receiving channel 73 and is threadedly engaged with the straight rod 202. The nut 3 has a grease inlet hole 14 that runs through its own axis and communicates with the grease injection section 72. In this embodiment, four grease inlet holes 14 are evenly distributed around the axis of the nut 3 to increase the flow area and further reduce the flow resistance of viscous sealing grease. This facilitates ensuring that the sealing grease flows smoothly and synchronously into the internal connecting section 731 of the valve body 1 from all directions, avoiding grease volume pressure or eddies that may be caused by unilateral flow, and ensuring the stability and efficiency of the grease injection process.

[0043] Continue to refer to Figure 2A pin 5 is installed on the valve body 1 and is perpendicular to the axis of the valve body 1. The pin 5 passes through the movable section 71. A grease injection spring 4 is located between the pin 5 and the sealing part 201. One end of the grease injection spring 4 is connected to the pin 5, and the other end is connected to the sealing part 201, so that the grease injection spring 4 applies a spring force to the sealing part 201 in the direction of the grease injection section 72. Under normal working conditions, the spring force of the grease injection spring 4 facilitates the closing action of the valve core 2, ensuring a tight seal between the sealing surfaces. In extreme cases, such as when the nut 3 fails to drive, the spring force of the grease injection spring 4 can still push the valve core 2 to achieve a basic seal, preventing the well pressure from running out of control.

[0044] Reference Figure 4 and Figure 5 In addition, the grease injection valve also includes a grease injection connector 15, which includes a connector nut 151, a central tube 152, a pressure cap 153, and a threaded sleeve 154. The connector nut 151 is threadedly engaged with the valve body 1. During the grease injection process, the sealing nut 6 needs to be removed and the connector nut 151 screwed onto the valve body 1.

[0045] The connector nut 151 has a connector cone surface 16 on the side near the valve body 1, which is adapted to the shape of the inner cone surface 9. The fit between the inner cone surface 9 and the connector cone surface 16 ensures the sealing stability of the connection between the valve body 1 and the connector nut 151. After the connector nut 151 is installed, the central tube 152 passes through and is movably fitted into the connector nut 151. To ensure the sealing stability between the connector nut 151 and the central tube 152, a sealing ring 17 is installed on the inner wall of the connector nut, and the sealing ring 17 abuts against the outer wall of the central tube 152.

[0046] Continue to refer to Figure 4 and Figure 5 A threaded sleeve 154 is fitted and threadedly engaged with the central tube 152, and a pressure cap 153 is threadedly engaged with the end of the connector nut 151 away from the valve body 1. Specifically, the pressure cap 153 has an axially extending accommodating movable hole 18, and the pressure cap 153 is screwed to the connector nut 151 through an internal thread in the accommodating movable hole 18. The pressure cap 153 has an external hexagonal structure to facilitate rotation using external tools such as wrenches. The threaded sleeve 154 is located within the accommodating movable hole 18, that is, between the connector nut 151 and the pressure cap 153, and the threaded sleeve 154 is cylindrical. The connector nut 151 has a connector movable groove 19 on the side facing the threaded sleeve 154, which is adapted to the shape of the threaded sleeve 154, so as to partially accommodate the threaded sleeve 154 through the connector movable groove 19.

[0047] Reference Figure 5The nut 3 has a rectangular groove 20 on the side near the connector nut 151. One end of the central tube 152 has an insertion protrusion 21 that matches the shape of the rectangular groove 20 and engages with it. When the pressure cap 153 is rotated, the pressure cap 153 pushes the threaded sleeve 154 to drive the central tube 152 to move axially. When the insertion protrusion 21 at the end of the central tube 152 is inserted into the rectangular groove 20 of the grease injection valve nut 3, rotating the central tube 152 can directly drive the nut 3 to rotate forward or backward, thereby ultimately remotely controlling the opening and closing of the downhole valve core 2, facilitating stable and active control of grease injection operations.

[0048] Reference Figure 5 Furthermore, the central tube 152 is threaded with two parallel caps 22. These two parallel caps 22 are located on the side of the pressure cap 153 furthest from the connector nut 151 and are tightly fitted together. Both parallel caps 22 have an external hexagonal structure to facilitate rotation using external tools such as wrenches. When the parallel caps 22 rotate, the central tube 152 rotates together. The arrangement of the two parallel caps 22 provides a reliable and secure point of force for the rotation of the central tube 152, effectively preventing loosening or displacement of any single point of force during repeated forward and reverse rotation of the central tube 152 to transmit torque. This ultimately ensures precise operation of the downhole grease injection valve opening and closing.

[0049] Continue to refer to Figure 5 To facilitate the connection between the central tube 152 and the grease injection tool, a connector plug 23 is inserted along the central tube 152 and movably fitted therein. The connector plug 23 has external threads to facilitate connection with the grease injection tool. To ensure the stability of the connector plug 23 after connection, a limiting sleeve 24 is threaded at the end of the central tube 152 away from the connector nut 151. The end of the connector plug 23 facing the limiting sleeve 24 has a connector receiving hole 25 that matches the shape of the limiting sleeve 24, so as to partially accommodate the limiting sleeve 24, thereby limiting the mutual positioning of the limiting sleeve 24 and the connector plug 23.

[0050] The implementation principle of Example 1 is as follows: When the nut 3 is rotated through the grease injection connector 15, the cooperation of the limiting strip 12 and the limiting groove 13 restricts the rotation of the valve core 2, thereby converting the rotational motion of the nut 3 into the linear motion of the valve core 2. This drives the sealing part 201 away from or presses against the opening of the grease injection section 72, thus realizing the opening and closing of the grease injection section 72. The method of actively and precisely controlling the movement of the valve core 2 by rotating the nut 3 through the grease injection connector 15 to open and close the opening of the grease injection section 72 ensures that even under the resistance of viscous sealing grease, the operator can reliably close the valve, achieving a stable seal on the valve body 1. This allows the grease injection valve to effectively isolate the pressure inside the well, facilitating the removal of the grease injection tool at the rear end of the grease injection valve, restoring the original state of the wellhead device, and ensuring the safe and smooth operation of the grease injection. Example 2

[0051] Reference Figure 6 The difference between this embodiment and embodiment 1 is that, in this embodiment, the outer peripheral surface of the valve body 1 is also integrally provided with a valve body indicator 26. The longitudinal section of the valve body indicator 26 is rectangular, and each side of the valve body indicator 26 is parallel to each groove wall of the rectangular groove 20.

[0052] The central tube 152 is fixedly provided with a connector indicator 27 by threaded connection. The longitudinal section of the connector indicator 27 is also rectangular. One side of the connector indicator 27 abuts against the side of the cap 22 near the valve body 1 away from the other cap 22, so as to ensure the stability of the position of the connector indicator 27.

[0053] Continue to refer to Figure 6 In this embodiment, the connector indicator 27 has four connector indicator edges 271, each of which is parallel to the side edge of the insertion protrusion 21. This allows the operator to connect the grease injection connector 15 without needing to look inside. They only need to rotate the center tube 152 externally to align the indicator edge of the connector indicator 27 with the corresponding edge of the valve body indicator 26. This ensures that the internal insertion protrusion 21 and the rectangular groove 20 are aligned in the circumferential direction, thereby improving the docking efficiency of the grease injection connector 15 and the valve body 1 and avoiding damage to parts caused by repeated trial and error.

[0054] The implementation principle of this embodiment is the same as that of Embodiment 1, and will not be repeated here.

[0055] This application also discloses a grease injection method, including the following steps: S1, removing the sealing nut 6 of the sealing valve body 1 and connecting the grease injection connector 15 to the valve body 1, specifically, threading the connector nut 151 of the grease injection connector 15 to the valve body 1.

[0056] S2, connect the end of the grease injection connector 15 away from the valve body 1 to the grease injection tool.

[0057] S3, operate grease injection connector 15, open grease injection valve.

[0058] Specifically, in step S31, the pressure cap 153 is screwed in, and the pressure cap 153 drives the central tube 152 to move axially by pushing the threaded sleeve 154; in step S32, when the screwing force is blocked, the central tube 152 is rotated by applying force to one of the caps 22 away from the valve body 1 with a wrench, and the insertion protrusion 21 of the central tube 152 is inserted into the rectangular groove 20 of the nut 3 in conjunction with the screwing in of the pressure cap 153; in step S33, the central tube 152 is rotated by applying force through one of the caps 22, and at this time, the sealing part 201 of the valve core 2 moves away from the nut 3, thereby opening the grease injection valve.

[0059] S4. Grease is injected into the wellhead device through the grease injection tool. The sealing grease flows from the grease injection tool through the inner hole of the central tube 152, the grease inlet hole 14 of the nut 3, and the grease injection hole 7, which is the annular channel between the valve body 1 and the valve core 2, and enters the wellhead device.

[0060] Note: S41, before grease injection, you can observe the pressure gauge at the front end of the grease injection tool. If the pressure rises, it confirms that the grease injection valve has been opened.

[0061] S5, after completing the required amount of grease injection, the grease injection process ends.

[0062] S6, by applying force to the other cap 22 near the valve body 1 with a wrench, the central tube 152 rotates in the opposite direction. At this time, the sealing part 201 of the valve core 2 moves towards the nut 3. When the sealing cone surface 10 and the sealing concave surface 11 are pressed together, the grease injection valve is closed.

[0063] Note: S61, after tightening the central tube 152, slowly depressurize through the pressure relief valve of the rear grease injection tool, then close the pressure relief valve and observe the pressure gauge. If the pressure no longer rises, it means that the grease injection valve has been completely closed; otherwise, the grease injection valve has not been completely closed, and step S6 needs to be repeated.

[0064] S7, Remove the grease injection tool.

[0065] S8, loosen the pressure cap 153, apply force to move the central tube 152 axially away from the valve body 1, so that the insertion protrusion 21 of the central tube 152 disengages from the rectangular groove 20 of the nut 3.

[0066] S9, loosen the connector nut 151, remove the grease fitting 15, and install the sealing nut 6 on the valve body 1.

[0067] The implementation principle of this application embodiment is as follows: during the grease injection process, the rotating nut 3 is rotated through the grease injection connector 15, so that the rotating nut 3 actively and precisely controls the movement of the valve core 2 to open and close the opening of the grease injection section 72. This ensures that even under the resistance of viscous sealing grease, the operator can reliably close the valve, achieve stable sealing of the valve body 1, and thus enable the grease injection valve to effectively isolate the pressure inside the well, making it easy to remove the grease injection tool at the rear end of the grease injection valve, restore the original state of the wellhead device, and ensure the safe and smooth progress of the grease injection operation.

[0068] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A grease injection valve, comprising a valve body (1) and a valve core (2), characterized in that: It also includes a nut (3), and the valve body (1) has a grease injection hole (7) that runs through it along its own axis. The grease injection hole (7) includes a movable section (71), a grease injection section (72), and a receiving channel (73) that are connected in sequence. The valve core (2) includes a fixedly disposed sealing part (201) and a straight rod part (202). The sealing part (201) is located in the movable section (71) and is used to open and close one end of the grease injection section (72). One end of the straight rod part (202) extends into the receiving channel (73). The valve body (1) is provided with a limiting member that restricts the valve core (2) from rotating around its own axis. The nut (3) is located in the receiving channel (73) and is threadedly engaged with the straight rod part (202). The nut (3) has a grease inlet hole (14) that runs through it along its own axis and communicates with the grease injection section (72).

2. The grease injection valve according to claim 1, characterized in that: The receiving channel (73) includes a connecting section (731) and a receiving section (732). One end of the connecting section (731) is connected to the grease injection section (72), and the other end is connected to the receiving section (732). The inner diameter of the connecting section (731) is larger than the inner diameter of the grease injection section (72) and smaller than the inner diameter of the receiving section (732). The nut (3) is located inside the receiving section (732), and the grease inlet (14) is connected to the connecting section (731).

3. A grease injection valve according to claim 1, characterized in that: It also includes a grease injection spring (4) and a pin (5), the pin (5) being mounted on the valve body (1) and arranged perpendicular to the axis of the valve body (1), the pin (5) being located in the movable section (71), the grease injection spring (4) being located between the pin (5) and the sealing part (201), the grease injection spring (4) applying a spring force to the sealing part (201) in the direction of moving towards the grease injection section (72).

4. A grease injection valve according to claim 3, characterized in that: The sealing part (201) is provided with a sealing cone surface (10) at one end near the grease injection section (72), and the grease injection section (72) is provided with a sealing concave surface (11) that corresponds to the sealing cone surface (10) and is adapted in shape on the side near the sealing part (201).

5. A grease injection valve according to claim 1, characterized in that: The limiting component includes a limiting strip (12) fixedly installed on the outside of the sealing part (201), and the side wall of the movable section (71) is provided with a limiting groove (13) extending along the axis of the valve body (1), and the limiting strip (12) slides and fits in the limiting groove (13).

6. A grease injection valve according to claim 1, characterized in that: It also includes a grease injection connector (15), which includes a connector nut (151), a central tube (152), a pressure cap (153), and a threaded sleeve (154). The connector nut (151) is threadedly engaged with the valve body (1). The central tube (152) passes through and is movably engaged with the connector nut (151). The threaded sleeve (154) is fitted and threadedly engaged with the central tube (152). The pressure cap (153) is threadedly engaged with the end of the connector nut (151) away from the valve body (1). The threaded sleeve (154) is located between the connector nut (151) and the pressure cap (153). The nut (3) has a rectangular groove (20) on the side near the connector nut (151). One end of the central tube (152) is provided with an insertion protrusion (21) that is adapted to the shape of the rectangular groove (20) and is inserted into the rectangular groove (20).

7. A grease injection valve according to claim 7, characterized in that: The central tube (152) is threaded with two caps (22), and the two caps (22) are tightly fitted together.

8. A grease injection valve according to claim 7, characterized in that: A sealing ring (17) is installed on the inner wall of the connector nut (151), and the sealing ring (17) abuts against the outer wall of the central tube (152).

9. A grease injection valve according to claim 7, characterized in that: The valve body (1) is provided with a valve body indicator (26) on its outer peripheral surface. Each side of the valve body indicator (26) is parallel to the wall of the rectangular groove (20). The central tube (152) is fixedly provided with a connector indicator (27). The connector indicator (27) has a connector indicator edge (271) that is parallel to each side of the insertion protrusion (21).

10. A grease injection method, based on a grease injection valve according to any one of claims 1 to 9, characterized in that: Includes the following steps: S1, remove the sealing nut (6) of the closed valve body (1) and connect the grease injection connector (15) to the valve body (1). Specifically, connect the connector nut (151) of the grease injection connector (15) to the valve body (1) by thread. S2, connect the end of the grease injection connector (15) away from the valve body (1) to the grease injection tool; S3, operate the grease injection connector (15) and open the grease injection valve; S31, screw in the pressure cap (153), the pressure cap (153) drives the central tube (152) to move axially by pushing the threaded sleeve (154); S32, when the screwing force is blocked, the center tube (152) is rotated by applying force through one of the caps (22), and the screwing of the pressure cap (153) causes the insertion protrusion (21) of the center tube (152) to be inserted into the rectangular groove (20) of the nut (3); S33, continue to apply force through one of the caps (22) to rotate the central tube (152). At this time, the sealing part (201) of the valve core (2) moves away from the nut (3) and opens the grease injection valve. S4, grease is injected into the wellhead device through the grease injection tool. The sealing grease flows from the grease injection tool through the inner hole of the central tube (152), the grease inlet hole (14) of the nut (3), the grease injection hole (7), i.e. the annular channel between the valve body (1) and the valve core (2), and enters the wellhead device. S5, after completing the required amount of grease injection, the grease injection process ends; S6, by applying force through another cap (22) to make the central tube (152) rotate in the opposite direction, at this time, the sealing part (201) of the valve core (2) moves towards the nut (3), and when the sealing cone surface (10) and the sealing concave surface (11) are pressed together, the grease injection valve is closed; S7, Remove the grease injection tool; S8, loosen the pressure cap (153), apply force to move the central tube (152) axially away from the valve body (1), so that the insertion protrusion (21) of the central tube (152) disengages from the rectangular groove (20) of the nut (3); S9, loosen the connector nut (151), remove the grease fitting (15), and install the sealing nut (6) on the valve body (1).

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