Intensive plunger blowout preventer

Abstract

The invention discloses an intensive plunger blowout preventer which comprises a cylindrical blowout prevention pipe base, a flange is welded to the side wall, close to a gas production position, of the blowout prevention pipe base, a conversion connector and a high-pressure manual stop valve are sequentially and fixedly connected to the side wall of the flange, a limiting check block is arranged in the blowout prevention pipe base, and a lead screw sleeve is connected to the interior of the blowout prevention pipe base in a clamped mode through the limiting check block. The outer wall of the end, close to the blowout prevention pipe base, of the lead screw sleeve is sleeved with a capturing cylinder, the top end of the blowout prevention pipe base is in threaded connection with a blowout prevention pipe pressing cap, and a buffering rod is arranged in the blowout prevention pipe pressing cap and connected with the lead screw sleeve. The device is simple in structure and convenient to use, extra fire changing operation is not needed, a gas production tree wellhead process does not need to be changed, flange connection is only utilized, operation is conducted through an internal structure of the device, and an original plunger lateral capturing structure is optimized and adjusted to be vertical capturing; cost is saved, measure operation time is shortened, and the purpose of rapid production of the plunger well is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas well gas production equipment and relates to an intensive plunger blowout prevention device. Background Art

[0002] Conventional plunger wellhead blowout preventers use a double-tube drainage process, in which the blowout preventer is a double transverse tube structure, and the blowout preventer catcher is installed on the horizontal opposite side of the lower transverse tube. The catcher manual cock is on the outside of the blowout preventer. When the plunger needs to be caught, the catcher cock is screwed in. When the plunger reaches the lower transverse tube of the blowout preventer, the catcher head hooks between the plunger turbulence sealing grooves, and the plunger stops moving upward to achieve the capture function. However, this method has a complex structure and requires the installation of an auxiliary capture device at the wellhead, which increases the operation time and cost.

[0003] Therefore, the prior art proposes a single-tube drainage process, in which the blowout preventer adopts a straight-through structure with a simpler structure. There is no cross pipe on the outside of the blowout preventer, and the lower end is directly connected to the wellhead flange of the gas tree. The plunger wellhead adopts a single-tube drainage process, and the liquid lifted by the plunger to the wellhead is directly discharged from the gas tree channel. After the plunger reaches the small four-way position of the gas tree for drainage, the liquid column above the plunger occupies the upward space of the plunger, and there is no other channel to relieve pressure, resulting in the plunger being unable to be captured by the catcher on the side of the blowout preventer, which is a lack of an important function for the blowout preventer. Summary of the invention

[0004] The object of the present invention is to provide a compact plunger blowout prevention device, which has the characteristics of relying on the vertical capture inside the device to shorten the operation time.

[0005] The scheme of the present invention is an intensive plunger blowout preventer device, comprising a cylindrical blowout preventer base, a flange is welded on the side wall of the blowout preventer base close to the gas production point, a conversion joint and a high-pressure manual stop valve are fixedly connected to the side wall of the flange in sequence, a limit block is provided inside the blowout preventer base, a screw sleeve is clamped inside the blowout preventer base through the limit block, a capture tube is sleeved on the outer wall of one end of the screw sleeve close to the blowout preventer base, a blowout preventer pressure cap is threadedly connected to the top of the blowout preventer base, a buffer rod is provided inside the blowout preventer pressure cap, and the buffer rod is connected to the screw sleeve.

[0006] The present invention is also characterized in that: one end of the buffer rod is connected to the lead screw sleeve through a hexagonal connecting rod, the other end of the buffer rod passes through the blowout preventer pressure cap and is connected to a hexagonal catch handle, a buffer rubber is provided in the middle of the buffer rod, and the buffer rod passes through the blowout preventer pressure cap and is connected to a quick-open handle;

[0007] A buffer spring is arranged in the blowout preventer pressure cap, a buffer rod passes through the buffer spring, and a spring seat is arranged at the end of the buffer spring;

[0008] A locking mechanism is fixedly connected between the spring seat and the blowout preventer pressure cap, and a shock-absorbing pad is provided between the top end of the buffer rod and the blowout preventer pressure cap;

[0009] The bottom end of the screw sleeve is sleeved with a limit sleeve, and the limit sleeve and the limit stopper are both fixed by a hexagonal flat-end set screw;

[0010] The capture tube is made of elastic steel, and the bottom end is a six-petal internal chamfered hook;

[0011] A sealing ring is provided at the connection between the blowout preventer pressure cap and the blowout preventer base;

[0012] An O-ring is provided between the nozzle base and the conversion joint.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention can be switched to a capture state and a non-capture state through an overall structural design, which meets actual production needs;

[0015] 2. In order to effectively buffer the plunger after it moves upward to the lubricator, the present invention is designed to form a triple buffer compared with the single buffer of the conventional plunger, and the buffering effect is better;

[0016] 3. The present invention is applicable to gas trees of common specifications such as KQ65-70, KQ46-35, KQ78-70, etc. The capture tube can capture the plunger of the fishing neck of common specifications such as 35mm and 45mm, with a wide range of use and strong applicability;

[0017] 4. The present invention has a simple structure and is easy to use. It does not require additional hot work or modification of the gas production tree wellhead process. It only uses flange connections and relies on the internal structure of the device to operate. The original lateral capture structure of the plunger is optimized and adjusted to vertical capture. It saves costs, shortens the operation time of the measures, and achieves the purpose of rapid production of the plunger well. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the intensive plunger blowout prevention device of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the locking mechanism in the intensive plunger blowout prevention device of the present invention;

[0020] In the figure, 1. blowout preventer base, 2. blowout preventer pressure cap, 3. spring seat, 4. screw sleeve, 5. buffer rod, 6. limit block, 7. catch tube, 8. locking mechanism, 9. quick open handle, 10. shock absorbing pad, 11. hexagon socket flat end set screw, 12. limit sleeve, 13. buffer rubber, 14. buffer spring, 15. sealing ring, 16. hexagon socket catch handle, 17. O-ring, 18. conversion joint, 19. high-pressure manual stop valve, 20. flange. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The present invention provides an intensive plunger blowout prevention device, comprising a cylindrical lubricator base 1, the lubricator base 1 is used to connect with a gas tree, a flange 20 is welded on the side wall near the gas production location, and the flange on the upper end of the gas tree test valve is connected by bolts for extrusion and sealing. The application does not require wellhead welding to restore the wellhead of the gas tree, and a limit stopper 6 is provided inside the lubricator base 1. A lead screw sleeve 4 is clamped inside the lubricator base 1 through the limit stopper 6, and the lead screw sleeve 4 is clamped on the table of the limit stopper 6 of the lubricator base 1;

[0023] The top of the blowout preventer base 1 is threadedly connected with a blowout preventer pressure cap 2, which is used for buffering and undertaking the switching capture or discharge process. A buffer rod 5 is arranged inside the blowout preventer pressure cap 2, and the buffer rod 5 is connected to the lead screw sleeve 4. One end of the buffer rod 5 is a hexagonal hollow structure, which is connected to the lead screw sleeve 4 through a hexagonal connecting rod. The other end of the buffer rod 5 is connected to a hexagonal capture handle 16. The buffer rod 5 passes through the blowout preventer pressure cap 2 and is connected to a quick-open handle 9. There is an idle stroke in the middle of the buffer rod 5, and a buffer rubber 13 is installed in the middle of the idle stroke;

[0024] A buffer spring 14 is also arranged in the blowout preventer pressure cap 2, and the buffer rod 5 passes through the buffer spring 14. A spring seat 3 is arranged at the end of the buffer spring 14, and the bottom of the buffer spring 14 presses against the surface of the limit stopper 6.

[0025] A locking mechanism 8 is provided between the spring seat 3 and the blowout preventer pressure cap 2 , and a shock absorbing pad 10 is also provided on the outer surface of the buffer rod 5 .

[0026] The outer wall of the screw sleeve 4 close to the lubricator base 1 is sleeved with a capture tube 7, and the tail end of the capture tube is 150mm-160mm away from the bottom surface of the lubricator base flange. The position of the screw is relatively fixed and can only move up and down in the screw sleeve. The screw can be retracted or rotated out 100mm in the capture tube.

[0027] The bottom end of the lead screw sleeve 4 is sleeved with a limit sleeve 12 , and the limit sleeve 12 and the limit stopper 6 are both fixed by using a hexagon socket flat-end set screw 11 .

[0028] The catch tube 7 is made of elastic steel, and the bottom end is a six-petal inner chamfered hook. A sealing ring 15 is provided at the clamping position of the anti-blowout pipe pressure cap 2 and the anti-blowout pipe base 1 to prevent leakage, reduce friction and prevent pollution.

[0029] The side wall of the flange 20 is fixedly connected with a conversion joint 18 and a high-pressure manual stop valve 19 in sequence, which are used to relieve pressure when the device is performing fishing operations; an O-ring 17 is provided between the nozzle base 1 and the conversion joint 18. The O-ring 17 is cheap, simple to manufacture, reliable in function, and has simple installation requirements.

[0030] The working process of the present invention is as follows:

[0031] First, install it by fixing the lubricant preventer base 1 on the top of the gas tree with bolts through the flange, then insert the screw sleeve 4 and fix it on the surface of the limit block 6, finally use the lubricant preventer pressure cap 2 with the buffer spring 14 and buffer rubber 13 installed to spin it on the lubricant preventer base 1 through threaded connection, and install the high-pressure manual stop valve 19 on the side of the lubricant preventer base 1 and keep the stop valve closed.

[0032] When in the non-capturing state, confirm that the high-pressure manual stop valve 19 is in the closed state, and turn the hexagonal capture handle 16 clockwise until it cannot be turned. At this time, the tail end of the screw is at the very end of the capture tube 7. After the plunger goes up to the wellhead, it will only hit the tail end of the screw. At the same time, the tail end of the screw transmits the impact force of the plunger to the buffer spring 14, the buffer rubber 13 and the buffer rod 5. At this time, the plunger will not enter the capture tube 7, but can only hover in the small four-way position of the gas production tree. By switching to the non-capturing state of the simplified blowout preventer, the plunger can be used for normal drainage.

[0033] When in the capturing state, confirm that the high-pressure manual stop valve 19 is in the closed state, and turn the hexagonal capturing handle 16 counterclockwise until it cannot be turned. At this time, the lead screw is lifted upward, and a 100mm space is left in the capturing tube 7 to allow the plunger to enter. When the plunger goes up to the wellhead, it is captured in the capturing tube 7, and the plunger fishing head hits the inner chamfer of the lower end of the capturing tube 7. The plunger fishing neck enters the capturing tube 7 and is locked by the hook, thereby realizing the wellhead capturing of the plunger. After confirming that the plunger is captured, switch the gas tree process, open the high-pressure manual stop valve 19 to relieve pressure, and when the pressure drops to zero, turn the quick-open handle 9, open the blowout preventer pressure cap 2 and remove the blowout preventer pressure cap 2, and further lift the screw sleeve 4 upward from the limit stopper 6. At this time, the plunger is in the capture tube 7 at the tail end of the screw sleeve 4. As the screw sleeve 4 is lifted, the plunger is also raised to the wellhead. Since the capture tube 7 is made of elastic steel, the plunger is bent downward to make the capture tube 7 and the plunger misaligned. At this time, the plunger is released from the capture tube 7, completing the plunger capture operation. Subsequently, according to production needs, if the plunger does not need to be captured in the next cycle, it is switched to the non-capture state and the gas tree process is restored, so that the plunger can be used for normal drainage; if the plunger needs to be captured in the next cycle, the screw sleeve is kept in the captured state. At this time, the plunger will still enter the capture tube, maintain the gas tree process, and prepare for capturing the plunger in the next cycle.

[0034] The bottom surface of the flange of the lubricator base 1 is 700mm away from the center point of the small four-way valve of the gas tree, the tail end of the capture tube 7 is 150mm away from the bottom surface of the flange of the lubricator base, the tail end of the capture tube 7 is 550mm away from the center point of the small four-way valve of the gas tree, and the length of the plunger is 500mm. When the plunger body has completely passed through the small four-way valve, the airflow under the plunger can enter the gas collection process of the gas tree through the small four-way valve. The single-tube drainage structure of the gas tree 8# valve can achieve the same continuous flow effect as the double-tube structure. Therefore, the plunger body must maintain a certain speed to completely pass through the small four-way valve. In this case, the plunger may be captured by the capture tube 7.

[0035] In order to effectively buffer the plunger after it ascends to the blowout preventer, compared with the single buffer of the conventional plunger, the invention is designed to form a triple buffer: the buffer spring 14 in the blowout preventer pressure cap 2, the buffer rubber 13 and the liquid column above the plunger. Since the plunger outer diameter is 59.5mm and the main diameter of the gas tree is 65mm, the plunger may have a lifting liquid leakage during the upward movement of the gas tree. When the plunger passes through the small four-way of the gas tree, the liquid column above the plunger flows through the gas tree 8# pipeline into the ground gas collection pipeline, and the other liquid column remains above the plunger and is compressed, leaking back to the bottom of the well from the gap between the main diameter and the outer wall of the plunger. During this upward process, the liquid column above the plunger does not rebound completely rigidly after compression, but due to the existence of the leakage phenomenon, the liquid column has a certain limit of reverse elastic buffering on the plunger, so the buffering performance of the invention is better than that of the conventional plunger blowout preventer.

[0036] In order to make the device meet the requirements during installation, the device is designed to have the same specifications as the gas tree, such as KQ65-70, KQ46-35, KQ78-70 and other common gas trees; similarly, the capture tube 7 can capture the plunger of the salvage neck of common specifications such as 35mm, 45mm, etc.

[0037] Example 1

[0038] The blowout prevention device of this embodiment includes a cylindrical lubricant preventer base 1, a flange 20 is welded to the side wall of the lubricant preventer base 1 near the gas extraction point, a conversion joint 18 and a high-pressure manual stop valve 19 are fixed to the side wall of the flange 20 in sequence, a limit block 6 is provided inside the lubricant preventer base 1, a lead screw sleeve 4 is clamped inside the lubricant preventer base 1 through the limit block 6, a capture tube 7 is sleeved on the outer wall of one end of the lead screw sleeve 4 near the lubricant preventer base 1, a lubricant preventer pressure cap 2 is threadedly connected to the top of the lubricant preventer base 1, a buffer rod 5 is provided inside the lubricant preventer pressure cap 2, and the buffer rod 5 is connected to the lead screw sleeve 4;

[0039] One end of the buffer rod 5 is a hexagonal hollow structure, which is connected to the screw sleeve 4 through a hexagonal connecting rod. The other end of the buffer rod 5 passes through the blowout preventer pressure cap 2 and is connected to the hexagonal capture handle 16. A buffer rubber 13 is provided in the middle of the buffer rod 5. The buffer rod 5 passes through the blowout preventer pressure cap 2 and is connected to the quick-open handle 9.

[0040] Example 2

[0041] The blowout prevention device of this embodiment includes a cylindrical lubricant preventer base 1, a flange 20 is welded to the side wall of the lubricant preventer base 1 near the gas extraction point, a conversion joint 18 and a high-pressure manual stop valve 19 are fixed to the side wall of the flange 20 in sequence, a limit block 6 is provided inside the lubricant preventer base 1, a lead screw sleeve 4 is clamped inside the lubricant preventer base 1 through the limit block 6, a capture tube 7 is sleeved on the outer wall of one end of the lead screw sleeve 4 near the lubricant preventer base 1, a lubricant preventer pressure cap 2 is threadedly connected to the top of the lubricant preventer base 1, a buffer rod 5 is provided inside the lubricant preventer pressure cap 2, and the buffer rod 5 is connected to the lead screw sleeve 4;

[0042] One end of the buffer rod 5 is a hexagonal hollow structure, which is connected to the screw sleeve 4 through a hexagonal connecting rod. The other end of the buffer rod 5 passes through the anti-blowout pipe pressure cap 2 and is connected to the hexagonal catch handle 16. A buffer rubber 13 is provided in the middle of the buffer rod 5. The buffer rod 5 passes through the anti-blowout pipe pressure cap 2 and is connected to the quick-open handle 9.

[0043] A buffer spring 14 is provided in the blowout preventer pressure cap 2, a buffer rod 5 passes through the buffer spring 14, and a spring seat 3 is provided at the end of the buffer spring 14;

[0044] A locking mechanism 8 is fixedly connected between the spring seat 3 and the lubricator pressure cap 2 , and a shock-absorbing pad 10 is provided between the top end of the buffer rod 5 and the lubricator pressure cap 2 .

[0045] Example 3

[0046] The blowout prevention device of this embodiment includes a cylindrical lubricant preventer base 1, a flange 20 is welded to the side wall of the lubricant preventer base 1 near the gas extraction point, a conversion joint 18 and a high-pressure manual stop valve 19 are fixed to the side wall of the flange 20 in sequence, a limit block 6 is provided inside the lubricant preventer base 1, a lead screw sleeve 4 is clamped inside the lubricant preventer base 1 through the limit block 6, a capture tube 7 is sleeved on the outer wall of one end of the lead screw sleeve 4 near the lubricant preventer base 1, a lubricant preventer pressure cap 2 is threadedly connected to the top of the lubricant preventer base 1, a buffer rod 5 is provided inside the lubricant preventer pressure cap 2, and the buffer rod 5 is connected to the lead screw sleeve 4;

[0047] The bottom end of the lead screw sleeve 4 is sleeved with a limit sleeve 12, and the limit sleeve 12 and the limit stopper 6 are both fixed by a hexagon socket flat-end set screw 11;

[0048] The catching tube 7 is made of elastic steel, and the bottom end is a six-petal inner chamfered hook.

[0049] Example 4

[0050] The blowout prevention device of this embodiment includes a cylindrical lubricant preventer base 1, a flange 20 is welded to the side wall of the lubricant preventer base 1 near the gas extraction point, a conversion joint 18 and a high-pressure manual stop valve 19 are fixed to the side wall of the flange 20 in sequence, a limit block 6 is provided inside the lubricant preventer base 1, a lead screw sleeve 4 is clamped inside the lubricant preventer base 1 through the limit block 6, a capture tube 7 is sleeved on the outer wall of one end of the lead screw sleeve 4 near the lubricant preventer base 1, a lubricant preventer pressure cap 2 is threadedly connected to the top of the lubricant preventer base 1, a buffer rod 5 is provided inside the lubricant preventer pressure cap 2, and the buffer rod 5 is connected to the lead screw sleeve 4;

[0051] A sealing ring 15 is provided at the connection between the lubricator pressure cap 2 and the lubricator base 1;

[0052] An O-ring 17 is provided between the nozzle base 1 and the conversion joint 18 .

Claims

1. Intensive plunger blowout prevention device, characterized in that: The invention comprises a tubular lubricant base (1), wherein a flange (20) is welded to the side wall of the lubricant base (1) near the gas extraction point, a conversion joint (18) and a high-pressure manual stop valve (19) are fixedly connected to the side wall of the flange (20) in sequence, a limit stopper (6) is arranged inside the lubricant base (1), a lead screw sleeve (4) is clamped inside the lubricant base (1) through the limit stopper (6), a catch tube (7) is sleeved on the outer wall of one end of the lead screw sleeve (4) near the lubricant base (1), a lubricant pressure cap (2) is threadedly connected to the top end of the lubricant base (1), a buffer rod (5) is arranged inside the lubricant pressure cap (2), and the buffer rod (5) is connected to the lead screw sleeve (4).

2. The intensive plunger blowout prevention device according to claim 1 is characterized in that: One end of the buffer rod (5) is connected to the lead screw sleeve (4) via a hexagonal connecting rod, and the other end of the buffer rod (5) passes through the blowout preventer pressure cap (2) and is connected to a hexagonal catching handle (16). A buffer rubber (13) is provided in the middle of the buffer rod (5), and the buffer rod (5) passes through the blowout preventer pressure cap (2) and is connected to a quick-opening handle (9).

3. The intensive plunger blowout prevention device according to claim 2 is characterized in that: A buffer spring (14) is arranged inside the anti-blowout pipe pressure cap (2), the buffer rod (5) passes through the buffer spring (14), and a spring seat (3) is arranged at the end of the buffer spring (14).

4. The intensive plunger blowout prevention device according to claim 3 is characterized in that: A locking mechanism (8) is fixedly connected between the spring seat (3) and the blowout preventer pressure cap (2), and a shock-absorbing pad (10) is provided between the top end of the buffer rod (5) and the blowout preventer pressure cap (2).

5. The intensive plunger blowout prevention device according to claim 1, characterized in that: The bottom end of the screw sleeve (4) is sleeved with a limit sleeve (12), and the limit sleeve (12) and the limit block (6) are both fixed by means of a hexagonal flat-end set screw (11).

6. The intensive plunger blowout prevention device according to claim 1, characterized in that: The capture tube (7) is made of elastic steel, and the bottom end is a six-petal inner chamfered hook.

7. The intensive plunger blowout prevention device according to claim 1, characterized in that: A sealing ring (15) is provided at the connection between the lubricator pressure cap (2) and the lubricator base (1).

8. The intensive plunger blowout prevention device according to claim 1, characterized in that: An O-type sealing ring (17) is provided between the nozzle base (1) and the conversion joint (18).

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