Safety blowout prevention self-sealing device for rod falling in oil and gas exploitation

Abstract

The utility model discloses an oil and gas exploitation rod falling safety blowout prevention self-sealing device which comprises a main body, a cavity is formed in the main body, a plurality of isolation balls are placed in the cavity, a port is formed in the top end of the main body, a gland is arranged in the port, a pressing cap is arranged on the port in a sleeved mode, and a sealing ring is arranged on the pressing cap. The lower side of the inner wall of the pressing cap abuts against the top wall of the gland, and a packing box connecting cap is arranged at the bottom of the body. A first polish rod hole, a second polish rod hole and a third polish rod hole are formed in the top wall of the pressing cap, the gland body and the top wall of the packing box connecting cap in the vertical direction respectively, wherein the first polish rod hole, the second polish rod hole and the third polish rod hole contain the polish rods and are the same in hole diameter and axis. The device is simple in structure, high in practicability and reliability, capable of being used in cooperation with the packing box, capable of automatically locking a well mouth, free of seepage and leakage, good in sealing effect and capable of effectively avoiding leakage of a large amount of oil gas of a production oil well due to the fact that a polished rod is broken and falls into a well and sealing of the packing box fails.

Description

Technical Field

[0001] The utility model relates to the technical field of oil well production, in particular to a rod-fall safety anti-blowout self-sealing device for oil and gas production. Background Art

[0002] At present, most of the domestic and foreign oil industries use the rod pumping unit oil extraction process. When the pumping unit is working, it pulls the rod up and down and the connected pump rod and other components to drive the oil pump deep underground to work back and forth, thereby achieving the purpose of extracting underground crude oil. In order to prevent crude oil from leaking at the Christmas tree, a packing box and a blowout preventer are installed on the Christmas tree, relying on the compression packing in the packing box and the moving rod to achieve sealing. The rod often breaks due to the frequent up and down movement and bite stress, and under the action of gravity, the rod will fall into the wellbore. The sealing packing forms a channel due to the lack of the rod clamping, which causes the packing box seal to fail, and crude oil sprays out from the original channel that clamps the rod, the wellhead control fails, and the gathering and transportation system backflows and leaks, and a large amount of oil and gas is released in an unorganized manner. If it is not discovered in time, the consequences will be disastrous.

[0003] In response to this problem, improvements have been made to the sealing of packing boxes at home and abroad, including spring-powered ball seals, airbags and metal ball seals, but ultimately they have not been effectively applied for a long time due to the complex oil and gas medium environment. At present, multiple seals are used in packing box sealing, but there is no good technology to solve the self-sealing problem.

[0004] The prior art uses a wellhead multi-stage sealing device, which is a wellhead blowout preventer with deviation adjustment and multiple seals (such as Figure 1 It is mainly composed of functional components such as deflector, well sealer, blowout preventer, M-type packing, pneumatic seal, etc. The main functions of each part are:

[0005] Deviation adjuster: The device does not need to be adjusted during installation. It is automatically coaxial with the polished rod and has flexible movement. After it is concentric, just tighten the cover. It swings with the polished rod to solve the eccentric wear phenomenon and extend the service life of the packing and the polished rod.

[0006] Well sealer: The well sealer has built-in V-shaped packing, which is composed of a mixture of graphite, carbon fiber, rubber, etc. and has a long service life. During normal production, the well sealer is in an unsealed state. When the air-sealing packing is worn out and leakage is about to occur, tighten the packing box gland to seal it and replace the worn air-sealing packing.

[0007] Blowout preventer: When the polished rod is disconnected, the liquid and gas will push the blowout preventer ball upward into the place where the polished rod is disconnected, automatically closing the polished rod channel to prevent oil and gas injection; and butter is stored in the ball cabin to lubricate the polished rod and reduce friction resistance.

[0008] M-type packing: M-type packing is composed of a mixture of graphite, carbon fiber, rubber, etc., and has a long service life. It is micro-combined with the polished rod to achieve sealing, especially for heavy oil and high wax content pumping wells. When the pneumatic seal is damaged or suddenly burst, the M-type packing protects the wellhead from leakage and ensures the safe production of the pumping unit.

[0009] Pneumatic seal: Pneumatic seal is to install inflatable packing in the air storage tank. After inflation, the packing will hold the polished rod tightly in real time. When the packing and the polished rod are worn, the loss part will be automatically supplemented to achieve no gap, no dead angle, no leakage, and greatly extend the service life of the packing. The device is mainly improved in sealing materials and forms, using more wear-resistant packing materials to extend the service life of the packing; its technical advantage is the introduction of air seals, and the compensation for losses caused by wear has been greatly controlled; the blowout preventer it uses still uses a power push ball to plug the channel, and there is no technical improvement.

[0010] However, the prior art still has the following disadvantages:

[0011] 1. The automatic sealing ball used in this technology is in long-term contact with the polished rod, which can easily cause wear of the polished rod and the self-sealing ball, resulting in seal failure and breakage of the polished rod.

[0012] 2. The compression spring used for pushing rusts and sticks in the oil and gas production environment, thus failing.

[0013] 3. The device has a complex structure, many moving parts, and many failure points, and cannot be used effectively for a long time. Utility Model Content

[0014] The purpose of the utility model is to provide a safety blowout prevention self-sealing device for oil and gas production rod fall in order to solve the above problems.

[0015] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0016] A self-sealing device for preventing and blowing out of a rod fall during oil and gas production comprises a main body, a cavity is formed in the main body, a plurality of isolation balls are placed in the cavity, a port is formed at the top of the main body, a gland is formed in the port, a pressure cap is fitted on the port, and the lower side of the inner wall of the pressure cap abuts against the top wall of the gland, a packing box connecting cap is formed at the bottom of the main body, and a No. 1 polished rod hole, a No. 2 polished rod hole and a No. 3 polished rod hole with the same aperture and coaxial center for accommodating the polished rod are respectively formed in the vertical direction on the top wall of the pressure cap, the gland main body and the top wall of the packing box connecting cap.

[0017] Preferably, an internal thread is provided on the inner wall of the pressure cap, and an external thread is provided on the outer wall of the port. The pressure cap and the port are connected by matching threads. This arrangement facilitates the disassembly and assembly of the pressure cap.

[0018] Preferably, an arc groove matching the outer contour of the isolation ball is provided on the lower side wall of the gland at a position opposite to the No. 2 polished rod hole. Through this arrangement, when the polished rod breaks and falls and oil leaks, the isolation ball floats up and continues to block the No. 2 polished rod hole under the action of oil pressure. The design of the arc groove can increase the contact area between the isolation ball and the No. 2 polished rod hole, thereby increasing the sealing performance.

[0019] Preferably, a plurality of force-adding rod seats are vertically fixed on the outer side wall of the main body, and force-adding rods are installed on the force-adding rod seats. This arrangement facilitates the transportation and installation of the device.

[0020] Preferably, an internal thread is provided on the inner side of the boosting rod seat, an external thread is provided on one end of the boosting rod, and the boosting rod is connected to the boosting rod seat by thread matching. This arrangement facilitates assembly and disassembly of the boosting rod, is easy to use, and has strong practicality.

[0021] Preferably, the isolation ball adopts a wear-resistant, corrosion-resistant, and high-pressure resistant hollow ball structure. Through this configuration, the overall average density of the isolation ball is small, which makes it easier for the isolation ball to float on the oil.

[0022] Preferably, an interface for connecting to the packing box is provided at the bottom end of the packing box connecting cap. This arrangement facilitates connection and use with the packing box.

[0023] Preferably, the transition section connecting the main body and the port adopts a gradual diameter closing design, so that when the polished rod breaks and drops oil to leak, the isolation ball floats up to guide the isolation ball into the arc groove at the isolation position at the bottom of the No. 2 polished rod hole in the upper part of the inner cavity.

[0024] Preferably, an annular partition is fixedly provided at the bottom of the cavity of the main body at a position opposite to the No. 3 light rod hole, and a plurality of plate-shaped partitions are fixedly provided between the partition ring and the inner wall of the cavity, and the isolation ball is placed between the plate-shaped partitions. Through this arrangement, the isolation ball and the light rod can be effectively isolated to prevent the isolation ball and the light rod, or the isolation ball and the isolation ball from touching each other, thereby causing damage to the isolation ball or the light rod, while not affecting the operation of the isolation ball.

[0025] Preferably, a limiting groove is provided at the bottom of the cavity of the main body between the plate-like partitions, and the limiting groove matches the outer contour of the isolation ball. Through this arrangement, the isolation ball is placed in the limiting groove for limiting position, thereby preventing the vibration generated during the operation of the device from causing the isolation ball to roll irregularly in the cavity, causing the isolation ball to collide with the inner wall of the cavity, the plate-like partition or the annular partition, resulting in an uneven surface and reduced sealing effect.

[0026] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0027] The device has the advantages of simple structure, strong practicability and high reliability, and can be used in conjunction with a packing box. When the polished rod breaks and falls into the well and the seal of the packing box fails, the device can automatically lock the wellhead without seepage or leakage, and has good sealing effect, which can effectively prevent large-scale oil and gas leakage in production wells due to seal failure caused by polished rod breaking, thereby causing safety and environmental accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is a structural schematic diagram of a wellhead multi-stage sealing device in the background technology of the utility model;

[0030] Figure 2 It is a three-dimensional diagram of a safety blowout prevention self-sealing device for oil and gas production rod falling described in the utility model;

[0031] Figure 3 This is a front view of a rod-fall safety anti-blowout self-sealing device for oil and gas production described in the utility model;

[0032] Figure 4 It is a cross-sectional view from the main perspective of a self-sealing device for preventing blowout when a rod falls during oil and gas production according to the utility model;

[0033] Figure 5 This is a diagram of the use status of the oil and gas production rod falling safety anti-blowout self-sealing device described in the utility model;

[0034] Figure 6 This is a schematic diagram of the spacer and partition structure of a safety blowout prevention self-sealing device for oil and gas production rod falling described in the utility model Figure 1 ;

[0035] Figure 7 This is a schematic diagram of the spacer and partition structure of a safety blowout prevention self-sealing device for oil and gas production rod falling described in the utility model Figure 2 .

[0036] The following are the descriptions of the reference numerals:

[0037] 1. Main body; 2. Port; 3. Pressure cap; 4. Gland; 5. Packing box connection cap; 6. Boosting rod seat; 7. Boosting rod; 8. Isolation ball; 9. Polished rod; 10. No. 1 polished rod hole; 11. No. 2 polished rod hole; 12. No. 3 polished rod hole; 13. Arc groove; 14. Cavity; 15. Interface; 16. Annular spacer; 17. Plate spacer; 18. Limit groove. DETAILED DESCRIPTION

[0038] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0040] The utility model is further described below in conjunction with the accompanying drawings:

[0041] Example 1

[0042] like Figure 2-Figure 7 As shown, a rod-fall safety and blowout-proof self-sealing device for oil and gas production comprises a main body 1, a cavity 14 is opened in the main body 1, a plurality of isolation balls 8 are placed in the cavity 14, a port 2 is arranged at the top of the main body 1, a gland 4 is arranged in the port 2, a pressure cap 3 is fitted on the port 2, and the lower side of the inner wall of the pressure cap 3 is in contact with the top wall of the gland 4, a packing box connecting cap 5 is arranged at the bottom of the main body 1, and a No. 1 polished rod hole 10, a No. 2 polished rod hole 11 and a No. 3 polished rod hole 12 with the same aperture and coaxial center for accommodating a polished rod 9 are respectively opened in the vertical direction on the top wall of the pressure cap 3, the main body of the gland 4 and the top wall of the packing box connecting cap 5.

[0043] Preferably, the inner wall of the pressure cap 5 is provided with an internal thread, the outer wall of the port 2 is provided with an external thread, and the pressure cap 5 and the port 2 are connected by matching threads. This arrangement facilitates the disassembly and assembly of the pressure cap 5.

[0044] An arc groove 13 matching the outer contour of the isolation ball 8 is provided on the lower side wall of gland 4 at a position opposite to the No. 2 polished rod hole 11. Through this arrangement, when the polished rod 9 breaks and falls and oil leaks, the isolation ball 8 floats up and continues to block the No. 2 polished rod hole 11 under the action of oil pressure. The design of the arc groove 13 can increase the contact area between the isolation ball 8 and the No. 2 polished rod hole 11 and improve the sealing performance.

[0045] A plurality of force-adding rod seats 6 are vertically fixed on the outer side wall of the main body 1 , and force-adding rods 7 are installed on each of the force-adding rod seats 6 . This arrangement facilitates the transportation and installation of the device.

[0046] An internal thread is provided inside the boosting rod seat 6, and an external thread is provided at one end of the boosting rod 7. The boosting rod 7 is connected to the boosting rod seat 6 through thread matching. This arrangement facilitates the disassembly and assembly of the boosting rod 7, is easy to use, and has strong practicality.

[0047] The isolation ball 8 adopts a wear-resistant, corrosion-resistant, and high-pressure resistant hollow ball structure. Through this configuration, the overall average density of the isolation ball 8 is relatively small, making it easier for the isolation ball 8 to float on the oil.

[0048] The bottom end of the packing box connecting cap 5 is provided with an interface 15 for connecting the packing box. This arrangement facilitates the connection and use with the packing box.

[0049] The transition section connecting the main body 1 and the port 2 adopts a gradual diameter closing design. When the polished rod 9 breaks and drops oil leakage occurs, the isolation ball 8 floats up to guide the isolation ball 8 into the isolation position arc groove 13 at the bottom of the second polished rod hole 11 in the upper part of the inner cavity 14.

[0050] An annular partition net 16 is fixedly arranged at the bottom of the cavity 14 of the main body 1, opposite to the No. 3 polished rod hole 12. A plurality of plate-shaped partition nets 17 are fixedly arranged between the partition ring 16 and the inner wall of the cavity 14. The isolation ball 8 is placed between the plate-shaped partition nets 17. This arrangement can effectively isolate the isolation ball 8 from the polished rod 9, and the isolation ball 8 from the isolation ball 8, to prevent the isolation ball 8 from touching the polished rod 9, and the isolation ball 8 from touching the isolation ball 8, which would cause damage to the isolation ball 8 or the polished rod 9, while not affecting the operation of the isolation ball 8.

[0051] A limiting groove 18 is provided between the plate-like partitions 17 at the bottom of the cavity 14 of the main body 1, and the limiting groove 18 matches the outer contour of the isolation ball 8. Through this arrangement, the isolation ball 8 is placed in the limiting groove 18 for limiting, preventing the vibration generated during the operation of the device from causing the isolation ball 8 to roll irregularly in the cavity 14, causing the isolation ball 8 to collide with the inner wall of the cavity 14, the plate-like partition 17 or the annular partition 16, resulting in an uneven surface and reduced sealing effect.

[0052] Working principle: The main body 1 of the device is integrally formed with high strength, and the overall tolerance can reach more than 25MPa. Before using the device, it is necessary to use the interface at the bottom of the packing box connecting cap 5 to connect with the packing box for use, and a cavity 14 is opened in the main body 1. An isolation ball 8 is placed in the cavity 14 and between the plate-like partitions 17. At most one isolation ball 8 is placed between the plate-like partitions 17. The total number of isolation balls 8 in the cavity 14 is more than one, usually two, and the design of the plate-like partition 17 or the annular partition 16 can effectively isolate the isolation ball 8 from the light rod 9, and the isolation ball 8 from the isolation ball 8, to prevent the isolation ball 8 from touching the light rod 9, and the isolation ball 8 from touching the isolation ball 8, so as to cause damage to the isolation ball 8 or the light rod 9;

[0053] The isolation ball 8 adopts a wear-resistant, corrosion-resistant, and high-pressure resistant hollow ball structure, with a pressure resistance of not less than 25MPa. The average density of the isolation ball 8 as a whole is less than 0.9, which makes it easy for the isolation ball 8 to float on the oil;

[0054] A port 2 is provided at the top of the main body 1, and a gradual diameter closing design is adopted. When the polished rod 9 breaks and drops oil to cause leakage, the isolation ball 8 floats up to guide the isolation ball 8 into the arc groove 13 at the isolation position at the bottom of the No. 2 polished rod hole 11 in the upper part of the inner cavity 14. The isolation ball 8 floats up under the buoyancy and pressure of the oil to block the No. 2 polished rod hole 11, thereby realizing the soft seal between the gland 4 and the isolation ball 8. In addition, the design of the arc groove 13 can increase the contact area between the isolation ball 8 and the No. 2 polished rod hole 11, and increase the sealing performance, thereby achieving the purpose of automatic sealing of the wellhead after the polished rod breaks off.

[0055] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, and these changes and improvements fall within the scope of the utility model to be protected.

Claims

1. A safety blowout prevention self-sealing device for oil and gas production, comprising a main body (1), characterized in that: The main body (1) is provided with a cavity (14), and a plurality of isolation balls (8) are placed in the cavity (14). The main body (1) is provided with a port (2) at the top, and a gland (4) is provided in the port (2). A pressure cap (3) is provided on the port (2), and the lower side of the inner wall of the pressure cap (3) abuts against the top wall of the gland (4). The bottom of the main body (1) is provided with a packing box connecting cap (5), and a first polished rod hole (10), a second polished rod hole (11) and a third polished rod hole (12) with the same aperture and coaxial center for accommodating a polished rod (9) are respectively provided in the vertical direction on the top wall of the pressure cap (3), the main body of the gland (4) and the top wall of the packing box connecting cap (5).

2. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: An internal thread is provided on the inner wall of the pressure cap (3), and an external thread is provided on the outer wall of the port (2); the pressure cap (3) and the port (2) are connected by matching threads.

3. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: An arc groove (13) matching the outer contour of the isolation ball (8) is provided on the lower side wall of the gland (4) at a position opposite to the second polished rod hole (11).

4. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: A plurality of force-adding rod seats (6) are vertically fixed on the outer side wall of the main body (1), and force-adding rods (7) are installed on each of the force-adding rod seats (6).

5. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 4 is characterized by: An internal thread is provided on the inner side of the boosting rod seat (6), an external thread is provided on one end of the boosting rod (7), and the boosting rod (7) and the boosting rod seat (6) are connected by matching threads.

6. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: The isolation ball (8) adopts a hollow ball structure that is wear-resistant, corrosion-resistant and high-pressure-resistant.

7. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: An interface (15) for connecting the packing box is provided at the bottom end of the packing box connecting cap (5).

8. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: The transition section connecting the main body (1) and the port (2) adopts a gradually changing diameter closing design.

9. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 1 is characterized by: An annular partition (16) is fixedly arranged at the bottom of the cavity (14) of the main body (1) at a position opposite to the No. 3 polished rod hole (12), and a plurality of plate-shaped partitions (17) are fixedly arranged between the annular partition (16) and the inner wall of the cavity (14), and the isolation ball (8) is placed between the plate-shaped partitions (17).

10. The oil and gas production rod falling safety anti-blowout self-sealing device according to claim 9, characterized in that: A limiting groove (18) is provided at the bottom of the cavity (14) of the main body (1) between the plate-shaped partition nets (17), and the limiting groove (18) matches the outer contour of the isolation ball (8).

Images