Universal automatic blowout preventer switch under pump and blowout prevention method

Abstract

The present invention relates to a universal automatic blowout preventer switch under the pump, which comprises two parts: a blowout preventer switch and a sliding controller. A sliding controller is provided at each end of the blowout preventer switch, and the two sliding controllers are arranged oppositely. The present invention also relates to a blowout prevention method for the universal automatic blowout preventer switch under the pump. The universal automatic blowout preventer switch under the pump of the present invention is easy to operate. When the tubing is lifted, it automatically closes, and when the tubing is lowered, it automatically opens. It can also be opened and closed at any time according to the construction needs. Automatic blowout prevention can be achieved during tubing and rod lowering, as well as rod and tubing lifting. Moreover, it has strong adaptability and can be used in pumping wells, progressing cavity pump wells and submersible electric pump wells, enabling environmental protection operation during oil well construction and preventing well site pollution.

Description

Technical Field

[0001] The present invention belongs to the field of oilfield mechanical equipment, and relates to a general-purpose downhole automatic blowout preventer switch and a blowout prevention method. Background Art

[0002] At present, the commonly used blowout preventers or downhole switches in oilfields can only solve the blowout prevention operation during pipe and rod lowering, and cannot achieve blowout prevention operations for other construction projects. Not only are they troublesome to operate (such as: filling water, applying pressure, rotating, poking with sucker rods, etc.), but they also cause wear to sucker rods or centralizers. Seriously, it is easy to cause downhole accidents such as pipe string leakage or pump and pipe sticking. Moreover, they are not suitable for screw pump wells and submersible electric pump wells. If the blowout prevention of an oil well is improper, then during construction, when working on tubing and sucker rods, etc., oil, water, and natural gas will spray out from the tubing, and the entire well site will be polluted by oil and water. The natural gas in the air will also cause very serious pollution to the atmosphere. Therefore, it is necessary to invent a new type of downhole blowout preventer switch for the above problems. Summary of the Invention

[0003] The first object of the present invention is to provide a general-purpose downhole automatic blowout preventer switch, which overcomes the problem that the current blowout preventer can only solve the blowout prevention operation during pipe and rod lowering and cannot achieve blowout prevention operations for other construction projects.

[0004] The second object of the present invention is to provide a blowout prevention method for the above general-purpose downhole automatic blowout preventer switch.

[0005] The present invention is achieved through the following technical solutions:

[0006] 1. A general-purpose downhole automatic blowout preventer switch includes two parts: a blowout preventer switch and a sliding controller. One sliding controller is provided at each end of the blowout preventer switch, and the two sliding controllers are arranged oppositely;

[0007] The sliding controller includes a compression cap, a first spring piece, a nylon threaded cylinder, and an opening cylinder. The compression cap and the opening cylinder are respectively connected to both ends of the nylon threaded cylinder by threads. The first spring piece is sleeved on the outer periphery of the nylon threaded cylinder and is located between the compression cap and the opening cylinder. The center of the first spring piece bulges outwards, and both ends of the first spring piece are pressed by the compression cap and the opening cylinder respectively;

[0008] The blowout prevention switch comprises a main body, an outer working cylinder, a switch sheet, a pin and a blind plate. The outer circumference of the main body is longitudinally provided with a plurality of grooves 1, the bottom of the groove 1 is provided with a plurality of liquid holes 1, the upper part of the groove 1 is provided with a liquid hole 2, the cavity in the main body is transversely provided with a blind plate, the blind plate is just located between the liquid hole 1 and the liquid hole 2, the groove 1 is provided with a switch sheet and the switch sheet can slide in the groove 1, and a channel 1 is also provided at a position corresponding to the liquid hole 2 on the switch sheet; the outer working cylinder is mounted on the main body and can slide along the main body, the inner wall of the outer working cylinder is circumferentially provided with an annular groove 2, the position of the groove 2 corresponds to the position of the groove 1, one end of the pin is fixedly connected to the outer working cylinder, and the other end is connected to the switch sheet.

[0009] The sliding controller can be just fitted onto the main body through the opening tube.

[0010] Furthermore, the switch sheet is also provided with a second spring sheet, the center of which bulges outwards, and a second hole is opened on the second spring sheet, the position of the second hole corresponds to the first hole on the switch sheet, and the pin passes through the second spring sheet to connect the switch sheet.

[0011] Furthermore, a liquid-passing plate is also provided at the lower part of the blind plate, the liquid-passing plate is located below the liquid-passing hole, and the liquid-passing plate is welded to the inner wall of the main body through a welding point.

[0012] Furthermore, a clamping ring is installed on the outer periphery of the main body, and the clamping ring is located below the outer working cylinder.

[0013] 2. A blowout prevention method according to the above-mentioned universal pump-under-automatic blowout prevention switch, the method comprising the following steps:

[0014] (1) Connect a tubing nipple to each end of the blowout preventer, and install a sliding controller on each tubing nipple. The two sliding controllers are placed opposite to each other, with the opening tube of the sliding controller facing the blowout preventer;

[0015] (2) When going down the well, the blowout preventer is in the closed state. After the sucker rod is lowered, the sliding controller at the bottom presses against the outer working cylinder of the blowout preventer. The outer working cylinder moves upward, driving the switch plate to slide through the pin. The channel 1 on the switch plate and the liquid hole 2 on the main body overlap. The liquid in the well enters from the bottom of the main body, passes through the liquid hole 1 on the main body, enters the cavity between the outer working cylinder and the main body, and then flows into the main body from the channel 1 and the liquid hole 2. The blowout preventer is in the open state.

[0016] (3) When the oil pipe is lifted, the upper sliding controller presses against the outer working cylinder of the blowout preventer, and the outer working cylinder moves downward, driving the switch plate to slide through the pin, so that the hole 1 and the liquid hole 2 are offset, and the blowout preventer is in the closed state.

[0017] Positive effects of adopting the above technical solution: The general-purpose downhole automatic blowout preventer switch of the present invention is easy to operate. When the tubing is lifted, it automatically closes, and when the tubing is lowered, it automatically opens. It can also be opened and closed at any time according to the construction needs. Automatic blowout prevention can be achieved during tubing and rod lowering, as well as rod and tubing lifting. Moreover, it has strong adaptability and can be used in pumping wells, progressing cavity pump wells, and submersible electric pump wells, enabling environmental protection operations during oil well construction and preventing wellsite pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the blowout preventer switch;

[0019] Figure 2 is a schematic structural diagram of the sliding controller;

[0020] Figure 3 is a side view of the blowout preventer switch;

[0021] Figure 4 is an internal unfolded view of the outer working cylinder;

[0022] Figure 5 is a schematic structural diagram of the present invention in the open state;

[0023] Figure 6 is a schematic structural diagram of the present invention in the closed state.

[0024] In the figure, 1 is the compression cap, 2 is the first spring piece, 3 is the nylon threaded cylinder, 4 is the open cylinder, 5 is the main body, 6 is the outer working cylinder, 7 is the switch piece, 8 is the pin, 9 is the blind plate, 10 is the first groove, 11 is the first liquid passing hole, 12 is the second liquid passing hole, 13 is the first channel, 14 is the second groove, 15 is the second spring piece, 16 is the second channel, 17 is the liquid passing plate, 18 is the snap ring. DETAILED DESCRIPTION OF THE INVENTION

[0025] The technical solution of the present invention will be further described below in conjunction with the drawings, but it should not be construed as a limitation to the present invention.

[0026] Figure 1 is a schematic structural diagram of the blowout preventer switch, Figure 2 is a schematic structural diagram of the sliding controller, Figure 3 is a side view of the blowout preventer switch, Figure 4 is an internal unfolded view of the outer working cylinder. As shown in the figure, a general-purpose downhole automatic blowout preventer switch includes two parts: a blowout preventer switch and a sliding controller. A sliding controller is provided at each end of the blowout preventer switch, and the two sliding controllers are arranged oppositely to control the opening and closing states of the blowout preventer switch through the sliding controller.

[0027] The sliding controller comprises a pressing cap 1, a spring sheet 2, a nylon threaded tube 3 and an open tube 4. The pressing cap 1 and the open tube 4 are respectively connected to the two ends of the nylon threaded tube 3 by threads. The spring sheet 2 is sleeved on the outer periphery of the nylon threaded tube 3 and is located between the pressing cap 1 and the open tube 4. The center of the spring sheet 2 bulges outwards, and the two ends of the spring sheet 2 are respectively pressed by the pressing cap 1 and the open tube 4. Since the center of the spring sheet 1 bulges outwards, it can support the sliding controller, so that the movement of the sliding controller is relatively lagging behind the oil pipe.

[0028] The blowout prevention switch comprises a main body 5, an outer working cylinder 6, a switch piece 7, a pin 8 and a blind plate 9. The main body 5 is longitudinally provided with a plurality of grooves 10, the bottom of the groove 10 is provided with a plurality of liquid holes 11, the upper part of the groove 10 is provided with a liquid hole 2 12, and the cavity in the main body 5 is transversely provided with a blind plate 9, which is located exactly between the liquid hole 11 and the liquid hole 2 12. Therefore, the blind plate blocks the central cavity of the main body, and the liquid can only pass through the liquid hole 1 and then enter the main body through the liquid hole 2. The switch piece 7 is provided in the groove 10 and the switch piece 7 can slide in the groove 10, and a channel 13 is also provided on the switch piece 7 at a position corresponding to the liquid hole 2 12. The sliding of the switch piece causes the channel 1 and the liquid hole 2 to overlap or stagger, thereby realizing the opening or closing of the blowout prevention switch. The outer working cylinder 6 is mounted on the main body 5 and can slide along the main body 5. The inner wall of the outer working cylinder 6 is provided with an annular groove 2 14 in the circumferential direction. The position of the groove 2 14 corresponds to the position of the groove 1 10. One end of the pin 8 is fixedly connected to the outer working cylinder 6, and the other end is connected to the switch piece 7. Therefore, the switch piece is controlled by the outer working cylinder and slides in the groove 1 as the outer working cylinder moves upward or downward.

[0029] The sliding controller can be just mounted on the main body 5 through the opening tube 4. The opening tube can resist the outer working tube, control the upward or downward movement of the outer working tube, and then drive the switch piece to achieve the effect of controlling the opening and closing of the anti-blowout switch.

[0030] Furthermore, the switch sheet 7 is also provided with a second spring sheet 15, the center of the second spring sheet 15 bulges outwards, a second hole 16 is provided on the second spring sheet 15, the second hole 16 corresponds to the position of the first hole 13 on the switch sheet 7, and the pin 8 passes through the second spring sheet 15 to connect the switch sheet 7. The function of the second spring sheet is similar to that of the first spring sheet, and because the center of the second spring sheet 1 bulges outwards, it can support the switch sheet to prevent liquid leakage.

[0031] As a further improvement of the present invention, the lower part of the blind plate 9 is also equipped with a liquid plate 17, which is located below the liquid hole 11. The liquid plate 17 is welded to the inner wall of the main body 5 through a welding point, so the liquid plate can be opened when it is under pressure. Paraffin with a relatively low melting point can be filled between the liquid plate and the blind plate. When the blowout preventer is lowered into the well, the paraffin will slowly melt due to the high temperature downhole, and the high pressure of the liquid in the well will flush the liquid plate and then pass through the liquid hole 1 on the main body. This design can play a role in delaying the opening of the blowout preventer.

[0032] The outer periphery of the main body 5 is also provided with a snap ring 18, which is located below the outer working cylinder 6. The snap ring can limit the movement of the outer working cylinder to prevent the outer working cylinder from going down excessively.

[0033] Figure 5 is a schematic diagram of the structure of the present invention when it is in an open state, Figure 6 It is a structural schematic diagram of the present invention when it is in a closed state. As shown in the figure, a method for preventing blowout of a universal pump-under automatic blowout prevention switch comprises the following steps:

[0034] (1) A tubing nipple is connected to each end of the blowout preventer, and a sliding controller is mounted on each tubing nipple. The two sliding controllers are placed opposite to each other, with the opening tubes of the sliding controllers facing the blowout preventer; the opening and closing states of the blowout preventer are controlled by the sliding controllers.

[0035] (2) When going down the well, the blowout preventer is in the closed state. After the sucker rod is lowered, the sliding controller at the bottom presses against the outer working cylinder 6 of the blowout preventer. The outer working cylinder 6 moves upward, driving the switch plate 7 to slide through the pin 8. The channel 13 on the switch plate 7 and the liquid hole 2 12 on the main body 5 overlap. The liquid in the well enters from the bottom of the main body 5, passes through the liquid hole 11 on the main body 5, enters the cavity between the outer working cylinder 6 and the main body 5, and then flows into the main body 5 from the channel 13 and the liquid hole 2 12. The blowout preventer is in the open state.

[0036] (3) When the oil pipe is lifted, the upper sliding controller presses against the outer working cylinder 6 of the blowout preventer, and the outer working cylinder 6 moves downward, driving the switch plate 7 to slide through the pin 8, so that the channel 13 and the liquid hole 2 12 are offset, the blowout preventer is in the closed state, and the liquid no longer flows.

[0037] When in use, first fill the space between the liquid plate and the blind plate with paraffin wax with a relatively low melting point, then connect a 1.5-2m tubing nipple to each end of the blowout preventer, and install a sliding controller on each nipple. The open pipe of the controller faces the blowout preventer, and it is lowered between the pump and the sand screen according to the direction marked on the blowout preventer. After the sucker rod is lowered, the friction of the sliding controller below increases under the action of the spring sheet 1, and it will not go down with the tubing, so it presses upward against the outer working cylinder of the blowout preventer, and the outer working cylinder moves upward, driving the switch sheet to slide through the pin, and the channel 1 on the switch sheet coincides with the liquid hole 2 on the main body. When the blowout preventer is lowered to the well, due to the high temperature downhole, the paraffin wax will slowly melt, and the liquid pressure in the well is high, the high-pressure liquid will flush the liquid plate, pass through the liquid hole 1 on the main body, enter the cavity between the outer working cylinder and the main body, and then flow into the main body from the channel 1 and the liquid hole 2, and the blowout preventer is in the open state. When the oil pipe is lifted up, the friction of the sliding controller above increases under the action of spring sheet 1, and it will not go up with the oil pipe, so it presses down against the outer working cylinder of the blowout preventer. The outer working cylinder moves downward, driving the switch sheet to slide through the pin, and the channel 1 and the liquid hole 2 are staggered, the blowout preventer is in the closed state, and the liquid no longer flows.

[0038] The universal automatic blowout prevention switch under the pump of the present invention is simple to operate. It automatically closes when the oil pipe is lifted up and automatically opens when the oil pipe is lowered. It can also be opened and closed at any time according to construction needs. Automatic blowout prevention can be achieved when the pipe is lowered and the rod is lowered, and when the rod is raised and the pipe is raised. It has strong adaptability and can be used in oil pumping wells, screw pump wells and submersible electric pump wells, so that environmentally friendly operations can be carried out during oil well construction to prevent pollution of the well site.

Claims

1. A universal downhole pump automatic blowout preventer switch, characterized in that: It includes a blowout preventer switch and two sliding controllers. One sliding controller is provided at each end of the blowout preventer switch, and the two sliding controllers are arranged oppositely; The sliding controller includes a compression cap (1), a first spring piece (2), a nylon threaded cylinder (3) and an open cylinder (4). The compression cap (1) and the open cylinder (4) are respectively connected to both ends of the nylon threaded cylinder (3) by threads. The first spring piece (2) is sleeved on the outer periphery of the nylon threaded cylinder (3) and is located between the compression cap (1) and the open cylinder (4). The center of the first spring piece (2) bulges outwards, and both ends of the first spring piece (2) are pressed by the compression cap (1) and the open cylinder (4) respectively; The blowout preventer switch includes a main body (5), an outer working cylinder (6), a switch piece (7), a pin (8) and a blind plate (9). A plurality of first grooves (10) are longitudinally provided on the outer periphery of the main body (5). A plurality of first liquid passing holes (11) are opened at the bottom of the first grooves (10), and a second liquid passing hole (12) is opened at the upper part of the first grooves (10). A blind plate (9) is transversely installed in the cavity inside the main body (5), and the blind plate (9) is exactly located between the first liquid passing holes (11) and the second liquid passing holes (12). A switch piece (7) is provided in the first grooves (10) and the switch piece (7) can slide in the first grooves (10). A first hole (13) is also opened at the position corresponding to the second liquid passing hole (12) on the switch piece (7); The outer working cylinder (6) is sleeved on the main body (5) and can slide along the main body (5). An annular second groove (14) is circumferentially opened on the inner wall of the outer working cylinder (6), and the position of the second groove (14) corresponds to that of the first grooves (10). One end of the pin (8) is fixedly connected to the outer working cylinder (6), and the other end is connected to the switch piece (7); The sliding controller can just be sleeved on the main body (5) through the open cylinder (4).

2. The universal downhole pump automatic blowout preventer switch according to claim 1, characterized in that: A second spring piece (15) is also installed on the switch piece (7). The center of the second spring piece (15) bulges outwards. A second hole (16) is opened on the second spring piece (15), and the position of the second hole (16) corresponds to that of the first hole (13) on the switch piece (7). The pin (8) passes through the second spring piece (15) to connect the switch piece (7).

3. The universal downhole pump automatic blowout preventer switch according to claim 1, characterized in that: A liquid passing plate (17) is also installed at the lower part of the blind plate (9). The liquid passing plate (17) is located below the first liquid passing holes (11), and the liquid passing plate (17) is welded to the inner wall of the main body (5) through a solder joint.

4. The universal downhole pump automatic blowout preventer switch according to claim 1, characterized in that: A snap ring (18) is also installed on the outer periphery of the main body (5). The snap ring (18) is located below the outer working cylinder (6).

5. A blowout prevention method for the universal downhole pump automatic blowout preventer switch according to claim 1, characterized in that: This method includes the following steps: (1)Connect a tubing nipple to each end of the blowout preventer switch, and fit a sliding controller on each tubing nipple. The two sliding controllers are placed facing each other, and the opening cylinder of the sliding controller faces the blowout preventer switch; (2)When lowering into the well, the blowout preventer switch is in the closed state. After the sucker rod is lowered, the lower sliding controller abuts against the outer working cylinder (6) of the blowout preventer switch. The outer working cylinder (6) moves upward, driving the switch blade (7) to slide through the pin (8). The first hole (13) on the switch blade (7) coincides with the second liquid passage hole (12) on the main body (5). The well fluid enters from the bottom of the main body (5), passes through the first liquid passage hole (11) on the main body (5), enters the cavity between the outer working cylinder (6) and the main body (5), and then flows into the main body (5) through the first hole (13) and the second liquid passage hole (12). The blowout preventer switch is in the open state; (3)When lifting the tubing, the upper sliding controller abuts against the outer working cylinder (6) of the blowout preventer switch. The outer working cylinder (6) moves downward, driving the switch blade (7) to slide through the pin (8). The first hole (13) and the second liquid passage hole (12) are offset, and the blowout preventer switch is in the closed state.

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