Sliding rod type non-grouting intelligent float valve and using method

Abstract

This invention discloses a sliding-rod type non-grouting intelligent float valve and its usage method, including a valve body shell, a limiting pressure capsule, a fixed sliding sleeve, and a curved valve seat disposed on the inner wall of the valve body shell. A movable sliding rod is disposed within the fixed sliding sleeve, with one end connected to the limiting pressure capsule and the other end rotatably connected to the curved valve plate. The curved valve seat is disposed between the curved valve plate and the limiting pressure capsule to work together with the curved valve plate to achieve a seal. A water hole is opened in the center of the curved valve seat. This invention's sliding-rod type non-grouting intelligent float valve completely changes the structure and operation of traditional drill bit internal blowout preventers. It avoids the use of springs and non-metallic line seals and the problem of improper selection of plate float valve cores causing the plate valve core to be pushed to the ground along the drill bit's inner hole. It achieves automatic all-metal surface sealing and positioning, has great practical value, and is easy to promote.

Description

Technical Field

[0001] This invention belongs to the technical field of internal blowout prevention tools in oil drilling, specifically to a sliding rod type non-grouting intelligent float valve and its usage method. Background Technology

[0002] During drilling, according to industry standards, if fluid overflows such as brine or oil / gas / nitrogen drilling may occur downhole, the drill string assembly near the drill bit must be equipped with a float valve or arrow-shaped check valve to prevent drilling fluid from flowing back into the drill bit or drill string, causing accidents such as blowouts inside the drill string.

[0003] Currently, the main types of blowout preventers (BOPs) used near the drill bit in downhole drilling tools are plate-type float valves and arrow-shaped check valves. These valves are deployed into the well. During drilling or workover, if a blowout, kick, or cessation of positive circulation occurs, the arrow-shaped check valve quickly closes under the pressure of reverse circulation and spring force within the drill string, cutting off the internal flow and preventing blowout. Plate-type float valves rely on non-metallic sealing parts and a spring-controlled valve plate for sealing. During use, inspections after tripping the drill string often reveal broken or softened springs, or failure of the non-metallic sealing parts, resulting in a failure rate exceeding 95%. In the event of a downhole blowout, well control cannot be guaranteed. Arrow-shaped check valves also rely on the one-way sealing principle of a spring and a cone valve to prevent blowout. During use, inspections after tripping the drill string frequently reveal broken or softened springs that fail to rebound, resulting in a sealing failure rate also exceeding 95%.

[0004] If, during the drilling process, the valve core remains in a normally closed state, the increased pressure from the inside and outside of the hydraulic column as the drilling depth increases will cause varying degrees of valve aging. It will be necessary to lower the valve to a certain depth, stop, and refill the drilling fluid in the water holes of the drill string, wasting a significant amount of non-productive time. Furthermore, even if these two types of valves do not fail, their structure is not designed to allow for bottomhole pressure reading without operating the pump after drilling. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a sliding rod-type non-grouting intelligent float valve and its usage method, which completely changes the structure and operation of traditional blowout preventers in the lower part of the drill string. It avoids the use of springs and non-metallic line seals and improper selection of plate float valve cores, which can cause the plate valve core to be pushed to the ground along the inner hole of the drill string. It achieves automatic all-metal surface sealing and positioning, and truly achieves efficient, safe, time-saving, and high-quality prevention of drilling fluid overflow in the drill string, prevention of cuttings clogging the water hole and blowout when nitrogen drilling opens the reservoir, and real-time measurement of bottom hole pressure after shut-in. It has great practical value and is easy to promote.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a sliding rod type non-grouting intelligent floating valve, comprising a valve body shell, a limiting pressure capsule, a fixed sliding sleeve, and a curved valve seat disposed on the inner wall of the valve body shell, wherein a movable sliding rod is disposed in the fixed sliding sleeve, one end of the movable sliding rod is connected to the limiting pressure capsule, and the other end is rotatably connected to the curved valve plate, the curved valve seat is disposed between the curved valve plate and the limiting pressure capsule for working together with the curved valve plate to achieve sealing, and a water hole is opened in the center of the curved valve seat.

[0007] Furthermore, the contact surface between the curved valve plate and the curved valve seat is curved, and a pressure-measuring hole is opened on the curved valve plate to form a pressure channel with the drilling platform for direct measurement of downhole pressure.

[0008] Furthermore, the contact surface between the curved valve seat and the curved valve plate is curved.

[0009] Furthermore, the curved valve seat is circumferentially sealed and fixed to the inner wall of the valve body shell.

[0010] Furthermore, the curved valve seat has multiple flow channels, which are evenly arranged around the water eye. The flow channels are guide grooves or guide holes.

[0011] Furthermore, the end of the movable slide bar away from the limiting pressure capsule is rotatably connected to the curved valve plate via the valve plate pivot.

[0012] Furthermore, the limiting pressure capsule is used to limit the movement of the sliding rod.

[0013] Furthermore, the fixed sliding sleeve has a T-shaped groove, and the movable sliding rod is a T-shaped sliding rod that is slidably engaged in the T-shaped groove.

[0014] Furthermore, the outer wall of the valve body is provided with threads, and the valve body is connected to the drill bit via the threads.

[0015] This invention also discloses a method for using a sliding-bar type non-grouting intelligent floating valve, the specific steps of which are as follows:

[0016] S1 connects the slide bar type non-grouting intelligent float valve to the drill string, sets the rupture pressure of the limit pressure capsule, and when the drill string enters the well and drills normally, the curved valve plate is in a drooping state, and the drilling fluid flows downward through the central water hole of the curved valve seat and participates in the operation normally.

[0017] S2 When the drill bit reaches the predetermined position and reaches the breaking pressure of the limit pressure capsule, the limit pressure capsule breaks, and the movable slide rod can slide within the fixed slide sleeve;

[0018] When a sudden overflow occurs, because the pressure at the bottom of the well is higher than the pressure inside the drill string, the drilling fluid flows back into the drill string through the drill bit water hole. The fluid moves upward, and the resulting force stimulates the curved valve plate. The movable slide rod drives the curved valve plate to move upward, forming a seal with the curved valve seat and blocking the fluid from flowing upward along the drill string.

[0019] When S4 is pulled out of the well, the pressure of the drilling fluid column inside the drill string is greater than the pressure at the bottom of the well, and the curved valve plate falls back naturally.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] This invention provides a sliding rod type non-grouting intelligent float valve, which achieves sealing during overflow through a movable sliding rod, a curved valve seat, and a curved valve plate. When high-pressure brine or oil and gas is encountered at the bottom of the well, causing a sudden overflow, the drilling fluid flows back into the drill string through the drill bit's water hole because the bottom-hole pressure is higher than the pressure inside the drill string. The upward movement of the fluid generates a force that activates the curved valve plate. Guided by the movable sliding rod, the curved valve plate moves upward and forms a seal with the curved valve seat, blocking the upward flow of downhole fluid into the drill string and preventing blowouts. Simultaneously, a water hole is located in the center of the curved valve seat, ensuring unobstructed access to the drill string and allowing for normal drilling operations. Therefore, this invention… The intelligent float valve does not require grouting into the drill string during the drilling process, avoiding the situation where the valve plate of a conventional float valve is always in the pipe wall state. This avoids the need to inject mud into the drill string during drilling to ensure the force balance of the conventional float valve, prevent damage to the valve plate due to unidirectional pressure, and save the time of special shutdown for grouting, thus protecting the valve plate. This invention achieves automatic all-metal surface sealing and positioning, truly achieving efficient, safe, time-saving, and high-quality prevention of drilling fluid overflow in the drill string, prevention of cuttings clogging the water hole and blowout when nitrogen drilling opens the reservoir, and real-time measurement of bottom hole pressure after well shut-in. It has great practical value and is easy to promote.

[0022] Furthermore, the curved valve plate is also equipped with a pressure-measuring hole. The bottom hole pressure can be transmitted to the drill table surface through the pressure-measuring hole along the drill string. When the pressure stabilizes, the downhole pressure can be read directly through the vertical pressure gauge. At the same time, because the pressure-measuring hole is small, it will not cause a blowout inside the drill string. Traditional internal blowout preventers do not have this hole, and can only start the pump at a small displacement, open the water hole, and establish a channel with the bottom of the well to obtain the bottom hole pressure. This traditional pressure-measuring process will cause reverse high pressure to the surface equipment, which is extremely risky.

[0023] Furthermore, the drill string and the valve body shell are directly connected by threads, and the male thread end of the upper drill string is directly pressed against the upper surface of the valve body to prevent the valve body from moving upward along the water hole of the drill string when drilling or overflowing, thus avoiding the unrestricted movement of the valve core of a conventional float valve within the water hole of the drill string. Attached Figure Description

[0024] Figure 1Top view of the sliding rod type non-grouting intelligent float valve of the present invention:

[0025] Figure 2 Schematic diagram of the sealing of the slide bar-type non-grouting intelligent floating valve of the present invention:

[0026] Figure 3 A schematic diagram of the slide bar-type non-grouting intelligent floating valve of the present invention in its unused state;

[0027] Figure 4 A schematic diagram of the curved valve plate 7 of the present invention.

[0028] In the attached diagram: 1. Valve body shell, 2. Limiting pressure capsule, 3. Movable slide bar, 4. Fixed slide sleeve, 5. Curved valve seat, 6. Flow channel, 7. Curved valve plate, 701. Pressure hole, 702. Valve plate shaft. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, this invention provides a sliding rod type non-grouting intelligent floating valve, comprising: a valve body shell 1, a limiting pressure capsule 2, a movable sliding rod 3, a fixed sliding sleeve 4, a curved valve seat 5, a flow channel 6, a curved valve plate 7, a pressure-sensing hole 701, and a valve plate rotating shaft 702. The limiting pressure capsule 2 is disposed on the inner wall of the valve body shell 1. One end of the fixed sliding sleeve 4 is connected to and fixed to the limiting pressure capsule 2 on the inner wall of the valve body shell 1. A movable sliding rod 3 is connected to the fixed sliding sleeve 4, and the end of the movable sliding rod 3 away from the limiting pressure capsule 2 passes through... The valve plate shaft 702 is rotatably connected to the curved valve plate 7. The curved valve seat 5 is located below the limiting pressure capsule 2 and is circumferentially sealed and fixed to the inner wall of the valve body shell 1. A water eye is provided in the center of the curved valve seat 5. A flow channel 6 is evenly opened around the water eye on the curved valve seat 5. The curved valve plate 7 is located below the curved valve seat 5. When there is overflow or blowout, the downhole fluid flows upward along the inside of the drill string, which can push the curved valve plate 7 to move upward. The sealing surface of the curved valve plate 7 and the curved valve seat 5 forms a seal, blocking the overflow or blowout inside the drill string.

[0031] Preferably, both the upper and lower ends of the valve body shell 1 are machined with threads for directly connecting the valve body shell 1 to the drill bit. The threads of the drill bit press against the upper end of the intelligent float valve seat, which serves as a limit.

[0032] Preferably, the limiting pressure capsule 2 is limited by the movable slide rod 3. A certain pressure is set on the ground, and after reaching a certain depth, the glue begins to break, losing its limiting function. The movable slide rod 3 can move freely up and down on the fixed slide sleeve 4, driving the curved valve plate 7 to move up and down and achieve sealing with the curved valve seat 5.

[0033] Preferably, the fixed sliding sleeve 4 has a T-shaped groove, and the movable sliding rod 3 is a T-shaped sliding rod, which is fixed in the T-shaped groove.

[0034] Preferably, the flow channel 6 is a flow guide groove or a flow guide hole.

[0035] Preferably, the upper surface of the curved valve plate 7 is curved, and the lower surface of the curved valve seat 5 is curved. The lower surface of the curved valve seat 5 can form a sealing surface with the upper surface of the upward curved valve plate 7. When an overflow occurs downhole, the curved valve seat 5 and the upward curved valve plate 7 together form a seal to block the blowout in the drill string.

[0036] Preferred, such as Figure 4 As shown, the curved valve plate 7 is also provided with a pressure-measuring hole 701. When a blowout occurs in the drill string, the curved valve plate 7 forms a seal with the sealing surface of the curved valve seat 5 to prevent blowout or overflow in the drill string. A small amount of liquid can form a pressure channel with the drill platform through the pressure-measuring hole 701. At this time, the ground riser can directly measure the downhole pressure.

[0037] Preferably, both the curved valve plate 7 and the curved valve seat 5 are made of metal to achieve full metal surface sealing of the intelligent float valve.

[0038] The specific steps for using the sliding rod type non-grouting intelligent floating valve of the present invention are as follows:

[0039] 1. For example Figure 3 As shown, the drill string is connected to the slide bar type non-grouting intelligent float valve of the present invention, the rupture pressure of the limit pressure capsule 2 is set, the drill string is lowered into the well, and during normal drilling, the curved valve plate 7 is in a drooping state, and the drilling fluid flows downward through the central water hole of the curved valve seat 5, and normally participates in drilling and other working conditions.

[0040] 2. During drilling, when the drill string reaches the predetermined position and the pressure of the limiting pressure capsule 2 is reached, the limiting pressure capsule 2 will break. Before the drill string reaches the final position and the capsule breaks, the movable slide rod 3 remains stationary, keeping the water holes inside the drill string unobstructed, thus completing the normal drilling process. At this time, there is no need to inject grout into the drill string during the drilling process, which avoids the conventional float valve's valve plate being constantly in the pipe wall state. It is necessary to inject mud into the drill string during drilling to ensure the force balance of the conventional float valve and prevent the valve plate from being damaged by unidirectional pressure. This saves the time required for special grouting and protects the valve plate.

[0041] 3. For example Figure 2 As shown, when high-pressure brine or oil and gas is encountered at the bottom of the well and a sudden overflow occurs, the drilling fluid flows back into the drill string through the drill bit's water hole because the bottom pressure is higher than the pressure inside the drill string. The fluid moves upward, and the resulting force stimulates the curved valve plate 7. Under the action of pressure difference, the movable slide rod 3 drives the curved valve plate 7 to move upward until the top curved surface of the curved valve plate 7 and the lower curved surface of the curved valve seat 5 are sealed, blocking the downhole fluid from flowing upward into the drill string and preventing the occurrence of a blowout inside the drill string.

[0042] 4. In the event of an overflow, after shutting in the well, the bottom hole pressure can be transmitted to the drill table surface along the drill string through the pressure-measuring hole 701 machined on the curved valve plate 7. Once the pressure stabilizes, the downhole pressure can be directly read through the vertical pressure gauge. At the same time, because the pressure-measuring hole 701 is relatively small, it will not cause a blowout inside the drill string. Traditional internal blowout preventers do not have this hole machined, and can only start the pump at a small displacement, open the water hole, and establish a channel with the bottom of the well to obtain the bottom hole pressure. This traditional pressure-measuring process will cause reverse high pressure to the surface equipment, which is extremely risky.

[0043] 5. When tripping out of the well, the pressure of the drilling fluid column inside the drill string is greater than the pressure at the bottom of the well. The curved valve plate 7 falls back naturally, and the drilling fluid flows back into the well under the action of the pressure difference at the bottom of the well. This avoids the drilling fluid inside the drill string flowing onto the drilling platform when the drill string is removed, thus preventing pollution of the working environment on the drilling platform.

[0044] 6. The drill string and the valve body housing 1 are directly connected by threads. The male thread end of the upper drill string is directly pressed on the upper surface of the valve body to prevent the valve body from moving upward along the water hole of the drill string when drilling or overflowing. This avoids the unrestricted movement of the valve core of a conventional float valve within the water hole of the drill string.

[0045] This tool and method are simple to use, with all-metal seals replacing non-metal seals. The valve core operates automatically throughout the entire process and will not be pushed to the ground. It is convenient for pressure measurement and is very easy to promote.

Claims

1. A sliding rod type non-grouting intelligent float valve, characterized in that, The valve body includes a valve body shell (1), a limiting pressure capsule (2), a fixed sliding sleeve (4), and a curved valve seat (5) disposed on the inner wall of the valve body shell (1). The fixed sliding sleeve (4) is provided with a movable sliding rod (3). One end of the movable sliding rod (3) is connected to the limiting pressure capsule (2), and the other end is rotatably connected to the curved valve plate (7). The curved valve seat (5) is disposed between the curved valve plate (7) and the limiting pressure capsule (2) for working together with the curved valve plate (7) to achieve sealing. A water hole is opened in the center of the curved valve seat (5). The contact surface between the curved valve plate (7) and the curved valve seat (5) is curved. A pressure-finding hole (701) is opened on the curved valve plate (7) to form a pressure channel with the drilling platform to facilitate direct determination of downhole pressure. The contact surface between the curved valve seat (5) and the curved valve plate (7) is curved; The limiting pressure capsule (2) is used to limit the movement of the sliding rod (3).

2. The sliding-bar type non-grouting intelligent floating valve according to claim 1, characterized in that, The curved valve seat (5) is circumferentially sealed and fixed to the inner wall of the valve body shell (1).

3. The sliding rod type non-grouting intelligent floating valve according to claim 1, characterized in that, Multiple flow channels (6) are opened on the curved valve seat (5). The multiple flow channels (6) are evenly arranged around the water eye. The flow channels (6) are guide grooves or guide holes.

4. The sliding rod type non-grouting intelligent floating valve according to claim 1, characterized in that, The end of the movable slide bar (3) away from the limiting pressure capsule (2) is rotatably connected to the curved valve plate (7) through the valve plate pivot (702).

5. A sliding-bar type non-grouting intelligent floating valve according to claim 1, characterized in that, The fixed sliding sleeve (4) has a T-shaped groove, and the movable sliding rod (3) is a T-shaped sliding rod, which is slidably locked in the T-shaped groove.

6. A sliding-bar type non-grouting intelligent floating valve according to claim 1, characterized in that, The outer wall of the valve body shell (1) is provided with threads, and the valve body shell (1) is connected to the drill bit through the threads.

7. The method of using a sliding-bar type non-grouting intelligent floating valve according to any one of claims 6, characterized in that, The specific steps are as follows: S1 connects the slide bar type non-grouting intelligent float valve to the drill string, sets the rupture pressure of the limit pressure capsule (2), when the drill string enters the well and drills normally, the curved valve plate (7) is in a drooping state, and the drilling fluid flows downward through the center water hole of the curved valve seat (5) and participates in the operation normally; When the drill bit reaches the predetermined position, it reaches the breaking pressure of the limiting pressure capsule (2), the limiting pressure capsule (2) breaks, and the movable slide rod (3) can slide inside the fixed slide sleeve (4); When S3 suddenly overflows, because the bottom hole pressure is higher than the drill string pressure, the drilling fluid flows back into the drill string through the drill bit water hole. The fluid moves upward and the resulting impact stimulates the curved valve plate (7). The movable slide rod (3) drives the curved valve plate (7) to move upward and form a seal with the curved valve seat (5), blocking the downhole fluid from going up along the drill string. When S4 is pulled out of the well, the pressure of the drilling fluid column inside the drill string is greater than the pressure at the bottom of the well, and the curved valve plate (7) falls back naturally.

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