Novel balance valve for coiled tubing blowout preventer

Abstract

The utility model discloses a novel balance valve for a coiled tubing blowout preventer. The novel balance valve comprises a valve body, a first valve element, a second valve element, a pressing screw plug and an elastic check ring. According to the novel balance valve, in the structural design, the first valve element and the second valve element are matched in a sealed mode to achieve opening and closing of the pressure relief channel, meanwhile, the rotating motion of the pressing screw plug is matched with the translational motion of the first valve element, control over advancing and retreating of the first valve element is achieved, and compared with a traditional balance valve, the novel balance valve is more suitable for the environment where frequent disassembly is conducted; the risks of damage to the valve element and abrasion of the sealing ring are reduced, the service life of the valve element is prolonged, and the maintenance and repair cost is reduced; in addition, through the arrangement of an elastic check ring, opening of the pressure relief channel is achieved, position reminding is achieved, and opening and closing are more convenient than traditional opening and closing in the field use process.

Description

Technical Field

[0001] The utility model relates to the technical field of blowout preventers, in particular to a novel balancing valve for a coiled tubing blowout preventer. Background Art

[0002] As the key part of the blowout preventer, it is very important to reduce the damage to the gate. The balancing valve can minimize the damage to the gate caused by high pressure during operation. The main purpose of the balancing valve is to make the pressure at the top and bottom of the gate in the closed state equal during downhole operations, well repairs, oil testing, etc.

[0003] The valve core and valve body of the traditional balancing valve are of threaded integrated design. Under high-pressure working environment, the threads need to be frequently turned to open and close the valve core, which makes the valve core and the sealing ring in contact with it extremely easy to be damaged. Therefore, in order to extend the life of the valve core and the sealing ring, it is necessary to design a new balancing valve structure for continuous tubing blowout preventers, which can ensure convenient operation while avoiding damage caused by frequent opening and closing of the valve core. Utility Model Content

[0004] The utility model aims to provide a novel balancing valve for a coiled tubing blowout preventer which solves the above technical problems.

[0005] To this end, the technical solution of the utility model is as follows:

[0006] A new type of balancing valve for a coiled tubing blowout preventer comprises a valve body, a first valve core, a second valve core, a clamping screw plug and an elastic retaining ring; wherein the second valve core is fixed to the front end of the valve body, and a central channel connected to the inner cavity of the valve body is axially opened on the second valve core, and a plurality of radial pressure relief holes connected to the central channel are evenly opened on the side wall of the rear end thereof in the circumferential direction; the clamping screw plug is arranged at the rear side of the valve body and is threadedly connected to the inner wall of the valve body, and an inner hexagonal blind hole is axially opened on the rear end surface of the clamping screw plug; the first valve core is inserted into an inner annular boss arranged on the inner wall of the valve body, and its rear end is connected to the clamping screw plug, and the front end is arranged as a tapered end; the inner diameter of the front side of the central channel of the second valve core is smaller than the inner diameter of the rear side, and the diameter change part is shaped A conical transition surface is formed, so that the front side of the first valve core is inserted into the rear side of the central channel of the second valve core, and its conical end is sealed and fitted with the conical transition surface of the second valve core, so as to block the communication channel between the multiple radial pressure relief holes and the central channel through the first valve core; a first lip sealing ring group is sleeved on the front side of the first valve core in the annular space surrounded by the first valve core, the valve body and the second valve core, so that the first valve core and the front side of the valve body are sealed and connected; an inner annular groove with a built-in elastic retaining ring is opened on the inner wall of the rear end of the valve body, and it is spaced from the clamping screw plug, so that when the clamping screw plug is rotated and retreated to the elastic retaining ring, it drives the first valve core to synchronously retreat to the multiple radial pressure relief holes and communicate with the central channel.

[0007] Furthermore, a T-shaped blind hole is axially opened on the front end face of the clamping screw plug to match the outer annular boss at the rear end of the first valve core, so that the rear end of the first valve core is embedded in the T-shaped blind hole to connect the first valve core with the clamping screw plug.

[0008] Furthermore, a first gasket and a second gasket are respectively provided on the front side of the first valve core and on both sides of the first lip sealing ring group. The first gasket and the second gasket are used to squeeze and tighten the first lip sealing ring group, thereby forming a tight seal between the front side of the first valve core and the front side cylinder of the valve body.

[0009] Furthermore, the outer diameter of the front cylinder of the valve body is smaller than the outer diameter of the rear cylinder, and an outer annular step is formed at the diameter change point of the two. An annular groove with a second lip sealing ring group built in is opened on the outer wall of the front cylinder of the valve body, so that the front cylinder of the valve body is sealably inserted into the balancing valve installation groove of the coiled tubing blowout preventer housing.

[0010] Furthermore, the front end outer diameter of the second valve core is smaller than the rear side outer diameter thereof, and is sleeved with a third lip seal ring group, so that the front end of the second valve core is sealed and inserted into the pressure relief groove at the bottom of the balancing valve mounting groove on the coiled tubing blowout preventer housing.

[0011] Compared with the prior art, the new balancing valve for the coiled tubing blowout preventer utilizes the sealing cooperation between the first valve core and the second valve core in structural design to realize the opening and closing of the pressure relief channel, and simultaneously utilizes the rotational movement of the clamping screw plug to cooperate with the translational movement of the first valve core to realize the control of the advance and retreat of the first valve core, so that the new balancing valve is more suitable for the environment of frequent disassembly compared with the traditional balancing valve, and reduces the risk of damage to the valve core and wear of the sealing ring, prolongs its service life, and reduces the maintenance and repair costs; in addition, through the setting of the elastic retaining ring, the reminder of the opening of the pressure relief channel by utilizing the position change is realized, and it is also more convenient to switch it during on-site use than the traditional one. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a new type of balancing valve for a coiled tubing blowout preventer of the utility model;

[0013] Figure 2 The utility model is a schematic diagram of the assembly structure of a new type of balancing valve for a coiled tubing blowout preventer and a blowout preventer housing. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0015] See also Figure 1 The novel balancing valve for the coiled tubing blowout preventer comprises a valve body 1, a first valve core 2, a second valve core 5, a clamping screw plug 7 and an elastic retaining ring 8.

[0016] The valve body 1 is a cubic cylinder, the inner diameter of the front cylinder is smaller than that of the rear cylinder, and an inner annular boss is provided on the inner wall of the cylinder at the diameter change point of the two; the inner diameter of the inner annular boss is smaller than the inner diameter of the front cylinder, and is adapted to the outer diameter of the first valve core 2, so that the first valve core 2 can pass through the rear cylinder, the inner annular boss and the front cylinder in sequence from the rear end of the valve body 1, and its front end extends to the outside of the front end of the valve body 1; a connecting internal thread is processed on the inner wall of the rear cylinder of the valve body 1.

[0017] The first valve core 2 is a cylindrical rod with a tapered end at the front end and a first outer annular boss on the outer wall of the rear end; a first gasket 3, a first lip-shaped sealing ring group 4 and a second gasket 9 are sequentially sleeved on the front side of the first valve core 2 from back to front, and the three are built into the annular gap formed between the first valve core 2 and the inner wall of the cylinder on the front side of the valve body 1. The first gasket 3 and the second gasket 9 squeeze and tighten the first lip-shaped sealing ring group 4, so that a seal is formed between the front side of the first valve core 2 and the cylinder on the front side of the valve body 1; in the present embodiment, the first lip-shaped sealing ring group 4 is composed of two lip-shaped sealing rings; the first gasket 3 and the second gasket 9 are made of red copper gaskets.

[0018] The second valve core 5 is a cylindrical barrel, the inner diameter of the rear barrel is larger than the inner diameter of the front barrel, and a conical transition surface matching the conical end of the first valve core 2 is formed at the diameter change portion; a second outer annular boss is provided on the outer wall at the rear end of the second valve core 5, and a plurality of radial pressure relief holes 501 are evenly distributed along the circumferential direction on the second outer annular boss, so that the rear barrel of the second valve core 5 is connected to the outside.

[0019] The rear end of the second valve core 5 is inserted and fixed to the front end of the cylinder of the valve body 1, so that it is coaxially arranged with the valve body 1, and the inner cavities of the two are connected; the inner diameter of the rear side cylinder of the second valve core 5 is adapted to the outer diameter of the rod body of the first valve core 2, so that the front side of the first valve core 2 is inserted in the rear side cylinder of the second valve core 5, and its tapered end cooperates with the tapered transition surface of the second valve core 5, and the tapered end of the second valve core 5 is used to block the connection between the inner cavity of the rear side cylinder of the second valve core 5 and the inner cavity of the front side cylinder.

[0020] The clamping screw plug 7 is a cylinder whose outer diameter is adapted to the inner diameter of the rear cylinder of the valve body 1. Its outer wall is provided with a connecting external thread that matches the connecting internal thread on the inner wall of the rear cylinder of the valve body 1, so that the clamping screw plug 7 is built-in and threadedly connected in the valve body 1; a T-shaped blind hole that matches the outer annular boss at the rear end of the first valve core 2 is axially opened on the front end face of the clamping screw plug 7, so that the rear end of the first valve core 2 is embedded in the T-shaped blind hole, thereby realizing the connection between the first valve core 2 and the clamping screw plug 7; an inner hexagonal hole that can match with an inner hexagonal wrench is axially opened on the rear end face of the clamping screw plug 7.

[0021] Since the balancing valve is frequently opened and closed under a high-pressure working environment, in this embodiment, the clamping screw plug 7 is embedded and connected with the first valve core 2, so that the clamping screw plug 7 can be easily replaced separately after it is damaged; at the same time, the rotational movement of the clamping screw plug 7 is utilized to convert the first valve core 2 from rotational translational movement to translational movement, thereby reducing the wear on the first lip sealing ring group 4, extending the life of the sealing ring, and reducing the maintenance cost of the entire balancing valve.

[0022] An inner annular groove is provided on the inner wall at the rear end of the valve body 1, and an elastic retaining ring 8 is built into the inner annular groove and initially arranged at a distance from the clamping plug 7; the elastic retaining ring 8 serves as a rotation limiting mechanism for the clamping plug 7 to prevent the clamping plug 7 from being screwed out of the valve body 1; wherein, the setting position of the elastic retaining ring 8 is matched with the opening state of the balancing valve, that is, when the clamping plug 7 rotates to abut against the elastic retaining ring 8, it just pulls the first valve core 2 backward to open the central channel of the second valve core 5 to communicate with multiple radial pressure relief holes 501.

[0023] The setting of the elastic retaining ring realizes the prompting of the pressure relief channel opening through position change, and also makes the switch more convenient than traditional ones during on-site use.

[0024] See also Figure 2 In actual application, the new type of balancing valve is installed in a balancing valve installation groove arranged on the shell of the coiled tubing blowout preventer, and the opening position of the balancing valve installation groove is adapted to the setting of the blowout preventer pressure relief channel; specifically, the balancing valve installation groove is opened from the outer wall of the coiled tubing blowout preventer shell along the direction of the blowout preventer pressure relief channel, so that the balancing valve installation groove is connected with the blowout preventer pressure relief channel; the inner diameter of the outer groove body 11 of the balancing valve installation groove is larger than the inner diameter of the inner groove body 13 thereof, and an inner annular step is formed at the diameter change position, so as to respectively install the valve body 1 and the second core valve 5 of the balancing valve; an inner annular step is provided on the inner wall of the groove bottom on the inner wall of the groove opening of the inner groove body 13.

[0025] As a preferred technical solution of this embodiment, the outer diameter of the front cylinder of the valve body 1 is smaller than the outer diameter of the rear cylinder, and an outer annular step is formed at the diameter change point of the two, so that the front cylinder of the valve body 1 is inserted into the outer groove body 11 of the balancing valve installation groove, and the end face of the outer annular step of the valve body 1 is abutted and fixed on the outer wall of the shell of the coiled tubing blowout preventer, and a pressure relief space 12 is left between the front end of the valve body 1 and the groove bottom of the outer groove body 11, and the pressure relief space 12 is connected with the radial pressure relief hole 501 of each second valve core 5; in order to ensure the sealing between the balancing valve and the shell of the coiled tubing blowout preventer, an annular groove is opened on the outer wall of the front cylinder of the valve body 1, and a second lip sealing ring group 6 is sleeved in the annular groove, so that the front cylinder of the valve body 1 is sealed and inserted in the outer groove body 11 of the balancing valve installation groove; wherein, the second lip sealing ring group 6 is composed of two lip sealing rings.

[0026] As another preferred technical solution of this embodiment, the outer diameter of the front end of the second valve core 5 is smaller than the outer diameter of the rear side thereof, and a third lip seal ring group 10 is sleeved thereon, so that the front end of the second valve core 5 is sealed and inserted into the inner groove body 13 of the balancing valve installation groove, so that the inner cavity of the second valve core 5 is connected with the pressure relief channel of the blowout preventer; wherein, the third lip seal ring group 10 is composed of three lip seal rings; the front end face of the third lip seal ring group 10 abuts against the inner annular step at the bottom of the inner groove body 13 to form a sealing fit and a buffer fit; preferably, an inner conical transition surface is formed on the inner wall of the groove of the inner groove body 13, and correspondingly, an outer conical transition surface matching the aforementioned inner conical transition surface is machined on the front end face of the second outer annular boss of the second valve core 5; this preferred structural design can not only ensure the sealed connection between the second valve core 5 and the blowout preventer, but also avoid damage caused by excessive force between the second valve core 5 and the balancing valve installation groove during the closing process of the balancing valve.

[0027] The working principle of the new balancing valve for coiled tubing blowout preventer is as follows:

[0028] When the lower gate of the blowout preventer is in a closed state, but the pressure difference between the upper and lower parts of the balancing valve balancer needs to be used, insert the hexagonal wrench into the hexagonal hole at the rear end of the clamping screw plug 7, and then rotate the clamping screw plug 7 counterclockwise for two to three circles, so that the clamping screw plug 7 retreats in the valve body 1 to the elastic retaining ring 8. At this time, the first valve core 2 retreats synchronously under the pull of the clamping screw plug 7 until the central channel of the second valve core 5 is opened and connected with the multiple radial pressure relief holes 501. At this time, the upper and lower parts of the gate cavity are connected to achieve pressure relief;

[0029] When it is necessary to close the connecting passage between the upper and lower parts of the gate cavity, insert the hexagonal wrench into the hexagonal hole at the rear end of the clamping screw 7, and then rotate the clamping screw 7 two to three turns clockwise to push the first valve core 2 forward until its tapered end fits tightly with the tapered transition surface of the inner wall of the second valve core 5 again, effectively cutting off the passage between the upper and lower parts of the gate and preventing pressure from flowing from the bottom of the gate to the top.

Claims

1. A new type of balancing valve for coiled tubing blowout preventer, characterized in that: The invention comprises a valve body (1), a first valve core (2), a second valve core (5), a clamping screw plug (7) and an elastic retaining ring (8); wherein the second valve core (5) is fixed at the front end of the valve body (1), and a central channel connected to the inner cavity of the valve body (1) is axially opened on the second valve core (5), and a plurality of radial pressure relief holes (501) connected to the central channel are evenly distributed in the circumferential direction on the side wall of the rear end thereof; the clamping screw plug (7) is arranged at the rear side of the valve body (1) and is threadedly connected to the inner wall of the valve body (1), and an inner hexagonal blind hole is axially opened on the rear end surface of the clamping screw plug (7); the first valve core (2) is inserted into an inner annular boss arranged on the inner wall of the valve body (1), and its rear end is connected to the clamping screw plug (7) and its front end is arranged as a tapered end; the front side of the first valve core (2) of the second valve core (5) is inserted into the middle of the second valve core (5) The valve body (1) and the second valve core (5) are connected to the rear side of the central channel and are sealed with the conical transition surface on the inner wall of the second valve core (5) through their conical end, so as to block the communication channel between the multiple radial pressure relief holes (501) and the central channel through the first valve core (2); a first lip seal ring group (4) is sleeved on the front side of the first valve core (2) in the annular space surrounded by the first valve core (2), the valve body (1) and the second valve core (5), so that the first valve core (2) and the front side of the valve body (1) are sealed; an inner annular groove with a built-in elastic retaining ring (8) is opened on the inner wall of the rear end of the valve body (1), and the inner annular groove is spaced apart from the clamping screw plug (7), so that when the clamping screw plug (7) rotates back to the elastic retaining ring (8), it drives the first valve core (2) to synchronously retreat to the multiple radial pressure relief holes (501) and communicate with the central channel.

2. The new type of balancing valve for coiled tubing blowout preventer according to claim 1 is characterized in that: A T-shaped blind hole is axially opened on the front end surface of the clamping screw plug (7) and matches the outer annular boss at the rear end of the first valve core (2), so that the rear end of the first valve core (2) is embedded in the T-shaped blind hole to achieve the connection between the first valve core (2) and the clamping screw plug (7).

3. The new type of balancing valve for coiled tubing blowout preventer according to claim 1 is characterized in that: A first gasket (3) and a second gasket (9) are respectively sleeved on the front side of the first valve core (2) and on both sides of the first lip seal ring group (4). The first gasket (3) and the second gasket (9) squeeze and tighten the first lip seal ring group (4), thereby forming a tight seal between the front side of the first valve core (2) and the front side cylinder of the valve body (1).

4. The new type of balancing valve for coiled tubing blowout preventer according to claim 1 is characterized in that: The outer diameter of the front cylinder of the valve body (1) is smaller than the outer diameter of the rear cylinder, and an outer annular step is formed at the diameter change point of the two. An annular groove with a second lip seal ring group (6) built in is provided on the outer wall of the front cylinder of the valve body (1), so that the front cylinder of the valve body (1) is sealably inserted into the balancing valve installation groove of the coiled tubing blowout preventer housing.

5. The new type of balancing valve for coiled tubing blowout preventer according to claim 1 is characterized in that: The front end outer diameter of the second valve core (5) is smaller than the rear side outer diameter thereof and is sleeved with a third lip seal ring group (10), so that the front end of the second valve core (5) is sealed and inserted into the pressure relief groove at the bottom of the balancing valve installation groove on the coiled tubing blowout preventer housing.

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