Back pressure valve for coiled tubing hanger

Abstract

The back pressure valve comprises a valve body, a valve body plug is arranged at the lower end of the valve body, the valve body comprises a valve body upper section and a valve body lower section, a first through hole is axially formed in the valve body upper section, a second through hole is axially formed in the valve body lower section, and the inner wall of the joint of the valve body upper section and the valve body lower section protrudes in the radial direction. A third through hole is formed in the connecting position of the valve body upper section and the valve body lower section, the first through hole, the second through hole and the third through hole are communicated, the diameter of the third through hole is smaller than that of the second through hole, a valve seat is arranged in the second through hole, a valve rod extending downwards in the axial direction is arranged at the lower end of the valve seat, a spring is arranged on the valve rod in a sleeved mode, and a J-shaped groove is formed in the top of the valve body upper section. An internal thread is arranged on the inner wall of the first through hole, and an external thread is arranged on the outer wall of the upper section of the valve body. The back pressure valve for the coiled tubing hanger is compact in structure, convenient to convey and take and suitable for plugging coiled tubing hangers with small inner diameters.

Description

Technical Field

[0001] The utility model relates to a back pressure valve for a coiled tubing hanger, belonging to the technical field of valve body products in oil and natural gas exploitation. Background Art

[0002] The coiled tubing oil and gas production technology is to select a coiled tubing with a smaller inner diameter to run into the wellhead oil casing, and use a coiled tubing hanger to hang the coiled tubing in the wellhead, so as to increase production by reducing the cross-sectional area of ​​the liquid or gas flowing in the well and increasing its flow speed in the pipe string. Therefore, the coiled tubing hanger has a smaller inner diameter than the traditional tubing hanger, and its back pressure valve thread is very small. A more compact back pressure valve is required to seal the coiled tubing hanger and prevent the liquid or gas in the well from flowing out of the well. At the same time, the smaller inner diameter of the coiled tubing hanger also increases the difficulty of installing and removing the back pressure valve.

[0003] The back pressure valve of the traditional tubing hanger is designed with a large through hole on the valve body for installing the valve seat, valve stem and spring. The back pressure valve of this structure is relatively large in size and not compact enough in structure. Utility Model Content

[0004] The utility model aims to provide a back pressure valve for a coiled tubing hanger. The back pressure valve for a coiled tubing hanger has a compact structure, is convenient to deliver and take, and is suitable for plugging a coiled tubing hanger with a smaller inner diameter.

[0005] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a back pressure valve for a coiled tubing hanger, which includes a valve body, a valve body plug is arranged at the lower end of the valve body, the valve body includes a valve body upper section and a valve body lower section, a first through hole is axially arranged in the upper section of the valve body, a second through hole is axially arranged in the lower section of the valve body, the inner wall of the connection between the upper section of the valve body and the lower section of the valve body is radially protruding, and a third through hole is arranged at the connection between the upper section of the valve body and the lower section of the valve body, and the first through hole and the second through hole are arranged in the lower section of the valve body. The valve body is connected to a third through hole, the diameter of the third through hole is smaller than the diameter of the second through hole, a valve seat is arranged in the second through hole, a valve stem extending axially downward is arranged at the lower end of the valve seat, the outer diameter of the valve seat is larger than the diameter of the third through hole, the diameter of the valve stem is smaller than the outer diameter of the valve seat, a spring is sleeved on the valve stem, the lower end of the spring is fixed on the valve body plug, a J-shaped groove is arranged on the top of the upper section of the valve body, an internal thread is arranged on the inner wall of the first through hole, and an external thread is arranged on the outer wall of the upper section of the valve body.

[0006] Preferably, the outer diameter of the upper section of the valve body is greater than the outer diameter of the lower section of the valve body.

[0007] Preferably, the lower end of the valve stem axially passes through the valve body plug.

[0008] Preferably, the inner wall of the lower section of the valve body is provided with an internal thread, the upper outer wall of the valve body plug is provided with an external thread matching the internal thread on the inner wall of the lower section of the valve body, and the valve body plug is connected to the lower section of the valve body through threads.

[0009] Preferably, the upper part of the valve body plug is screwed into the lower section of the valve body, a threaded hole is radially arranged on the lower section of the valve body, a locking screw is arranged in the threaded hole, and the end of the locking screw passes through the threaded hole to support the upper part of the valve body plug.

[0010] Preferably, a long hole is provided on the lower section of the valve body, and the long hole is communicated with the second through hole.

[0011] Preferably, a sealing ring is provided on the outer wall of the upper section of the valve body.

[0012] Preferably, an O-ring is provided on the outer wall of the upper section of the valve body.

[0013] The beneficial effects of the utility model are as follows: the back pressure valve for the continuous tubing hanger of the utility model adopts a split structural design of the valve body and the valve body plug, the valve stem and the valve seat adopt an integral design, the design size is reduced, the structure is compact, a J-shaped groove is designed on the valve body, the connection or disconnection with the delivery tool is convenient and quick, the back pressure valve and the continuous tubing hanger are sealed by an O-ring and a retaining ring, the sealing structure is simple and the cost is low, and the back pressure valve is installed in the continuous tubing hanger to seal the continuous tubing hanger with a smaller inner diameter to prevent the liquid or gas in the well from flowing out of the well, and the utility model is suitable for the field of continuous tubing oil and gas production technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0015] Figure 1 It is a cross-sectional view of the structure schematic diagram of the back pressure valve for the coiled tubing hanger of the utility model;

[0016] Figure 2 This is a schematic diagram of the structure of a back pressure valve for a coiled tubing hanger of the utility model;

[0017] Figures 3 to 5 It is a schematic diagram of the back pressure valve when the back pressure valve is inserted into the embodiment of the back pressure valve for the coiled tubing hanger of the utility model;

[0018] Figure 6 and Figure 7 It is a schematic diagram of the back pressure valve when the back pressure valve is taken out in the embodiment of the back pressure valve for the coiled tubing hanger of the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiments of the utility model:

[0021] The utility model provides a back pressure valve for a coiled tubing hanger. Figures 1 to 7 , comprising a valve body 1, a valve body plug 6 is arranged at the lower end of the valve body 1, the valve body 1 comprises a valve body upper section 8 and a valve body lower section 9, a first through hole 10 is axially arranged in the valve body upper section 8, a second through hole 11 is axially arranged in the valve body lower section 9, the inner wall of the connection between the valve body upper section 8 and the valve body lower section 9 radially protrudes, a third through hole 12 is arranged at the connection between the valve body upper section 8 and the valve body lower section 9, the first through hole 10, the second through hole 11 and the third through hole 12 are connected, and the diameter of the third through hole 12 is smaller than that of the first through hole 10. The diameter of the second through hole 11 is set, a valve seat 4 is set in the second through hole 11, and a valve stem 13 extending axially downward is set at the lower end of the valve seat 4, the outer diameter of the valve seat 4 is larger than the diameter of the third through hole 12, and the diameter of the valve stem 13 is smaller than the outer diameter of the valve seat 4, a spring 5 is sleeved on the valve stem 13, and the lower end of the spring 5 is fixed on the valve body plug 6, a J-shaped groove 14 is set on the top of the valve body upper section 8, an internal thread is set on the inner wall of the first through hole 10, and an external thread is set on the outer wall of the valve body upper section 8.

[0022] Preferably, the outer diameter of the valve body upper section 8 is greater than the outer diameter of the valve body lower section 9 .

[0023] Preferably, the lower end of the valve stem 13 axially passes through the valve body plug 6 .

[0024] Preferably, an internal thread is provided on the inner wall of the valve body lower section 9, and an external thread matching the internal thread on the inner wall of the valve body lower section 9 is provided on the upper outer wall of the valve body plug 6. The valve body plug 6 is connected to the valve body lower section 9 through threads, and the upper part of the valve body plug 6 is screwed into the valve body lower section 9.

[0025] Preferably, a threaded hole 15 is radially provided on the valve body lower section 9, and a locking screw 7 is provided in the threaded hole 15. The end of the locking screw 7 passes through the threaded hole 15 to support the upper part of the valve body plug 6, thereby fastening the valve body plug 6 and the valve body lower section 9 together to prevent the thread from loosening.

[0026] Preferably, a long hole 16 is provided on the lower section 9 of the valve body, and the long hole 16 is communicated with the second through hole 11 .

[0027] Preferably, a sealing ring 2 is provided on the outer wall of the upper section 8 of the valve body.

[0028] Preferably, an O-ring 3 is provided on the outer wall of the upper section 8 of the valve body.

[0029] When the back pressure valve for a coiled tubing hanger of the utility model is used, the back pressure valve is installed as follows: insert the delivery joint 18 of the delivery and removal tool 17 into the back pressure valve, the push rod 19 at the lower end of the delivery joint 18 pushes the valve seat 4 downward and compresses the spring 5, the pin 20 on the delivery and removal tool 17 is screwed into the J-shaped groove 14 of the back pressure valve, so that the delivery joint 18 is connected to the back pressure valve, and the back pressure valve is lowered by the delivery and removal tool 17. When the external thread of the upper section 8 of the valve body contacts the internal thread of the coiled tubing hanger 21, the delivery and removal tool 17 is rotated until the valve body 1 is installed in the coiled tubing hanger 21. At this time, the valve body 1 and the coiled tubing hanger 21 are sealed by the sealing retainer ring 2 and the O-ring 3. Then the delivery joint 18 is disengaged from the back pressure valve, and the valve seat 4 is reset under the action of the spring 5. At the same time, the spring 5 applies a certain pre-tightening force to the valve seat 4. The fluid in the oil and gas well enters the second through hole 11 through the long hole 16 at the lower end of the valve body 1, and pushes the valve seat 4 to move upward, so that the valve seat 4 and the sealing surface of the valve body 1 are closely fitted, preventing the liquid or gas in the well from flowing out of the well, thereby achieving the plugging of the coiled tubing hanger.

[0030] Removing the back pressure valve: lower the removal joint 22 of the delivery tool 17 through the delivery tool 17 until the external thread of the removal joint 22 contacts the internal thread of the inner wall of the first through hole 10 in the upper section 8 of the valve body, rotate the delivery tool 17, screw the removal joint 22 into the valve body 1, and gradually push the valve seat 4 downward and compress the spring 5. Continue to rotate the delivery tool 17 until the valve body 1 is disengaged from the coiled tubing hanger 21, and remove the back pressure valve.

[0031] The utility model discloses a back pressure valve for a coiled tubing hanger, which adopts a split structure design of valve body and valve body plug, and an integral design of valve stem and valve seat, which reduces the design size and has a compact structure. A J-shaped groove is designed on the valve body, which is convenient and quick to connect or disconnect with a delivery tool. An O-ring and a retaining ring are used for sealing between the back pressure valve and the coiled tubing hanger, and the sealing structure is simple and the cost is low. The valve is installed in the coiled tubing hanger to seal the coiled tubing hanger with a smaller inner diameter, so as to prevent liquid or gas in the well from flowing out of the well. The utility model is applicable to the technical field of coiled tubing oil and gas production.

[0032] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A back pressure valve for a coiled tubing hanger, comprising a valve body, a valve body plug being provided at the lower end of the valve body, characterized in that: The valve body comprises an upper valve body section and a lower valve body section, a first through hole is axially arranged in the upper valve body section, a second through hole is axially arranged in the lower valve body section, an inner wall of a connection between the upper valve body section and the lower valve body section radially protrudes, a third through hole is arranged at a connection between the upper valve body section and the lower valve body section, the first through hole, the second through hole and the third through hole are communicated, a diameter of the third through hole is smaller than a diameter of the second through hole, a valve seat is arranged in the second through hole, a valve stem extending axially downward is arranged at the lower end of the valve seat, an outer diameter of the valve seat is larger than a diameter of the third through hole, a diameter of the valve stem is smaller than an outer diameter of the valve seat, a spring is sleeved on the valve stem, the lower end of the spring is fixed to the valve body plug, a J-shaped groove is arranged at the top of the upper valve body section, an internal thread is arranged on the inner wall of the first through hole, and an external thread is arranged on the outer wall of the upper valve body section.

2. The back pressure valve for a coiled tubing hanger according to claim 1, characterized in that: The outer diameter of the upper section of the valve body is greater than the outer diameter of the lower section of the valve body.

3. The back pressure valve for a coiled tubing hanger according to claim 2, characterized in that: The lower end of the valve stem axially passes through the valve body plug.

4. The back pressure valve for a coiled tubing hanger according to claim 3, characterized in that: The inner wall of the lower section of the valve body is provided with an internal thread, the upper outer wall of the valve body plug is provided with an external thread matching the internal thread on the inner wall of the lower section of the valve body, and the valve body plug is connected to the lower section of the valve body through threads.

5. The back pressure valve for a coiled tubing hanger according to claim 4, characterized in that: The upper part of the valve body plug extends into the lower section of the valve body. The lower section of the valve body is radially provided with a threaded hole. A locking screw is provided in the threaded hole. The end of the locking screw passes through the threaded hole to support the upper part of the valve body plug.

6. The back pressure valve for a coiled tubing hanger according to claim 5, characterized in that: The lower section of the valve body is provided with a long hole, and the long hole is communicated with the second through hole.

7. The back pressure valve for a coiled tubing hanger according to claim 6, characterized in that: A sealing ring is arranged on the outer wall of the upper section of the valve body.

8. The back pressure valve for a coiled tubing hanger according to claim 7, characterized in that: An O-shaped sealing ring is arranged on the outer wall of the upper section of the valve body.

Images