Oil jacket double-control subsurface safety valve

Abstract

A rubber sleeve mandrel is fixed on the outer wall of a valve body, and a rubber sleeve is arranged on the outer wall of the rubber sleeve mandrel; a piston capable of axially moving is further arranged on the outer wall of the valve body, a push cylinder is fixed to the outer wall of the piston, and the upper end of the push cylinder can make contact with the lower end of the rubber cylinder; the lower end of the piston communicates with a through pressure transmitting hole in the side wall of the valve body. Abnormal pressure generated in a well is transmitted to the lower end of the piston through the pressure transmission hole, then the piston is pushed to move upwards, meanwhile, the pushing cylinder is driven to extrude the rubber cylinder upwards, and the rubber cylinder expands outwards after being pressed to achieve annular sealing. When the underground fluid abnormally flows, the pressure is relieved to close the valve plate, and the fluid pushes the piston to move upwards to extrude the rubber sleeve to expand outwards, so that the flow control of the abnormal fluid in an oil pipe and an oil sleeve annulus in a well is realized, and the plugging reliability of the underground abnormal fluid is improved.

Description

Technical Field

[0001] This utility model relates to a downhole development mechanical tool used in oil and gas wells to prevent blowouts, ensure oil and gas well measures, and ensure safe production; specifically, it is a dual-control downhole safety valve for oil and casing. Background Technology

[0002] During the development of oil and gas wells, the complex composition and high corrosiveness of oil and gas cause severe corrosion to downhole tools and casing. Furthermore, if harmful components leak due to unforeseen circumstances during production, it can seriously endanger human and environmental safety. Therefore, downhole safety valves are typically used to effectively control fluids downhole.

[0003] Downhole safety valves are control devices for fluids in abnormal flow conditions, such as fires in offshore production facilities, pipeline ruptures, or unavoidable natural disasters like earthquakes and typhoons. They automatically close in emergencies to control fluid flow in the well and are a crucial component of offshore completion strings. However, most current safety valves only control abnormal fluids within the tubing, requiring additional packers for dual-channel sealing. But if the packer's rubber sleeve fails or pressure leaks, uncontrolled fluid flow in the annulus can endanger human and environmental safety. Therefore, a new safety valve needs to be designed to provide dual control of both the tubing and the external annulus, ensuring effective control of fluids in both areas. Summary of the Invention

[0004] This invention aims to solve existing problems by providing a dual-control downhole safety valve for both oil and casing.

[0005] To achieve the above objectives, the technical solution adopted by this utility model includes a valve body, a valve mechanism is provided inside the valve body, and a packer is connected to the lower end of the valve body. The feature is that a rubber cylinder mandrel is fixed to the upper outer wall of the valve body, and a rubber cylinder is provided on the outer wall of the rubber cylinder mandrel.

[0006] The valve body is also provided with an axially movable piston on the outer wall of the middle part. A pusher is fixed on the outer wall of the piston. The upper end of the pusher can contact the lower end of the rubber tube. The lower end of the piston is connected to the pressure transmission hole that runs through the side wall of the valve body.

[0007] The abnormal pressure generated in the well is transmitted from the pressure transmission hole to the lower end of the piston, which in turn pushes the piston upward and drives the pusher to squeeze the rubber sleeve upward. After being compressed, the rubber sleeve expands outward to achieve annular sealing.

[0008] Furthermore, a piston outer cylinder is provided on the lower outer wall of the valve body, and a piston cavity is formed between the lower outer wall of the valve body and the middle inner wall of the piston outer cylinder, with the lower end of the piston located in the piston cavity; the two ends of the pressure transmission hole are respectively connected to the interior of the valve body and the piston cavity.

[0009] Furthermore, the pressure transmission port is located below the valve plate of the valve mechanism.

[0010] Furthermore, the upper outer wall of the valve body and the upper inner wall of the rubber sleeve spindle are connected by threads and are equipped with anti-rotation screws.

[0011] Furthermore, the outer wall of the piston and the inner wall of the push cylinder are connected by threads, and an anti-rotation screw is provided.

[0012] Furthermore, the lower outer wall of the valve body is connected to the lower inner wall of the piston outer cylinder by a thread, and an anti-rotation screw is provided.

[0013] Furthermore, the upper end of the piston is located between the upper outer wall of the valve body and the middle inner wall of the rubber sleeve spindle, and the inner and outer walls of the upper end of the piston are sealed with the upper outer wall of the valve body and the middle inner wall of the rubber sleeve spindle by O-rings.

[0014] Furthermore, O-rings are used to form a seal between the inner and outer walls of the lower end of the piston and the outer wall of the lower end of the valve body and the inner wall of the middle part of the piston outer cylinder.

[0015] Furthermore, the valve mechanism includes a valve plate seat, the lower end of which is rotatably connected to the valve plate via a torsion spring and a pin; it also includes a flow tube that can move axially, the outer wall of which is connected to the inner wall of the valve body via a compressed spring, and the upper end of which is connected to a control line; when the control line is pressurized, the pressure pushes the flow tube downward, and the lower end of the flow tube pushes the valve plate open downward; when the pressure is removed, the flow tube returns to its original position under the push of the spring, and the valve plate closes.

[0016] Furthermore, the upper end of the valve body is provided with an upward pressure chamber, and the upper end of the flow tube is provided with a piston rod. The piston rod is located in the upward pressure chamber, and the upward pressure chamber is connected to the control pipeline through the upward pressure hole; a seal is formed between the outer wall of the piston rod and the inner wall of the upward pressure chamber.

[0017] Furthermore, a seal is formed between the outer wall of the piston rod and the inner wall of the pressure-up chamber by a V-shaped sealing ring. Compared with the prior art, this invention, by setting a piston and rubber sleeve mechanism outside the safety valve body, first depressurizes and closes the valve plate when encountering abnormal flow of downhole fluid, while the fluid pushes the piston upward to squeeze the rubber sleeve outward to set the annulus, thus achieving emergency automatic closure and completing the flow control of abnormal fluid in the tubing and casing annulus. It can achieve dual sealing of the tubing and casing annulus without increasing construction difficulty, improving the reliability of sealing against abnormal downhole fluid. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention in the blocking state;

[0019] Figure 2This is a schematic diagram of the structure of the present invention in its initial state;

[0020] Figure 3 This is a schematic diagram of the piston rod structure;

[0021] Figure 4 This is a schematic diagram of the valve plate structure;

[0022] See the attached diagram: upper connector 1, rubber sleeve mandrel 2, rubber sleeve 3, piston rod 4, piston 5, push cylinder 6, flow tube 7, spring 8, spring cylinder 9, piston outer cylinder 10, valve plate seat 11, valve plate 12, torsion spring 13, pressure transmission hole 14, lower connector 15. Detailed Implementation

[0023] The present invention will now be further described with reference to the accompanying drawings. For ease of description, the following will refer to... Figure 2 The direction of the upper connector is "up" and the direction of the lower connector is "down".

[0024] See Figure 2 , Figure 2 This illustration shows the initial state of the dual-control downhole safety valve with oil casing according to an embodiment of this utility model. In this embodiment, the valve body includes an upper connector, a spring cylinder (middle connector), and a lower connector (roughly corresponding to the upper, middle, and lower ends of the valve body) connected sequentially from top to bottom; a valve mechanism is provided inside the valve body, and a packer is connected to the lower end of the valve body.

[0025] The outer wall of the upper connector is threaded to the upper inner wall of the rubber sleeve mandrel, and an anti-rotation screw is preferably added. A space is formed between the outer wall of the upper connector and the middle inner wall of the rubber sleeve mandrel for the upper end of the piston to extend and move. The outer wall of the rubber sleeve mandrel is provided with a rubber sleeve.

[0026] A piston that can move axially is provided on the outer wall of the middle part of the valve body (roughly corresponding to the outer wall of the spring cylinder). A push cylinder is fixed to the outer wall of the piston by threads; and an anti-rotation screw is preferably added. The upper end of the push cylinder can contact and squeeze the lower end of the rubber cylinder after it moves upward.

[0027] In this embodiment, the outer wall of the lower connector is threaded to the lower inner wall of the piston outer cylinder; and an anti-rotation screw is preferably added. A piston cavity is formed between the outer wall of the lower connector and the middle inner wall of the piston outer cylinder, and the lower end of the piston is located in the piston cavity. The side wall of the lower connector is provided with a through pressure transmission hole, and the pressure transmission hole is located below the valve plate of the valve mechanism inside the valve body. The two ends of the pressure transmission hole are respectively connected to the interior of the valve body and the piston cavity.

[0028] Furthermore, preferably, O-rings are used to form a seal between the inner and outer walls of the upper end of the piston and the outer wall of the upper connector, as well as the middle inner wall of the rubber sleeve mandrel. Similarly, O-rings are used to form a seal between the inner and outer walls of the lower end of the piston and the outer wall of the lower connector, as well as the middle inner wall of the piston outer cylinder.

[0029] Furthermore, the valve mechanism includes a valve plate seat, a valve plate, a torsion spring, a pin, and a flow tube, etc. The upper end of the valve plate seat is connected to the inner wall of the spring cylinder, and the lower end of the valve plate seat is open. The side of the opening is rotatably connected to the valve plate through the torsion spring and the pin. See details... Figure 4 The valve plate has a baffle structure. A pin is inserted into the corresponding hole in the valve plate holder on the valve plate seat. Two ear plates on one side of the valve plate pass through the pin, forming a hinge structure, allowing the valve plate to rotate around the pin. A helical torsion spring is used and is fitted onto the pin. One arm of the spring is fixed to the valve plate holder, while the other arm acts on the back of the valve plate, providing a preload torque for rotation. See also... Figure 1 and Figure 2 It also includes a flow tube that can move axially, and the outer wall of the flow tube is connected to the step on the inner wall of the spring cylinder by a spring in a compressed state.

[0030] Specifically, see Figure 3 The upper side wall of the upper connector is provided with a pressure-uploading chamber, and the upper end of the flow tube is provided with a piston rod, which extends into the pressure-uploading chamber from the lower end and is located inside it. The pressure-uploading chamber is connected to the control pipeline on the ground through the pressure-uploading hole at its upper part.

[0031] Preferably, a seal is formed between the outer wall of the piston rod and the inner wall of the pressure chamber by a V-shaped sealing ring. In use, this embodiment is connected in series in the tubing and vertically lowered into the well. Pressurization through the surface pipeline applies pressure to the upper end of the piston rod, pushing it downwards to overcome the spring force of the flow tube's outer wall. Subsequently, the lower end of the flow tube descends to the top valve plate, opening the safety valve.

[0032] During this process, the flow tube moves downward a certain distance and then contacts the valve plate. After the flow tube pushes open the valve plate, it continues to move downward until it contacts the lower step on the inner wall of the lower connector, thus limiting the downward stroke of the flow tube. At this point, the valve plate is in a fully open state, and the inner diameter of the safety valve is the inner diameter of the flow tube. At this time, the ground control line stops pressurizing, maintaining a constant pressure in the line and keeping the safety valve open.

[0033] When the packer and oil / gas well below it are in normal production, the valve plate is in the open state, and the piston is in the initial state because the pressure difference between the upper and lower parts is the same.

[0034] When special problems and well control risks occur, such as abnormal flow of downhole fluid requiring control, the pressure in the control line is first released. At this time, the pressure at the upper end of the piston rod disappears, and the flow tube is pushed upward by the spring force. At this time, the valve plate is no longer restricted by the flow tube and closes automatically under the torque of the torsion spring. The opening at the lower end of the valve plate and the valve plate seat is sealed by the double seal of metal and O-ring, which realizes the function of blocking abnormal fluid in the tubing.

[0035] See Figure 1 At this time, the fluid in the well below the valve plate flows abnormally and continues to generate pressure. The generated pressure is transmitted to the piston chamber through the pressure transmission hole on the side wall of the lower connector. Under the action of this pressure, the lower end of the piston moves upward and drives the pusher to squeeze the rubber sleeve upward. When the outer diameter of the rubber sleeve is squeezed and expanded to be the same as that of the casing, the setting seal is completed and the oil sleeve annulus is sealed.

[0036] At this point, both the tubing and the annulus are effectively sealed, achieving dual control of the tubing and annulus. After the abnormal fluid state in the well stabilizes, the pressure at the upper and lower ends of the valve plate balances, and the annulus sealing mechanism of the valve body releases its seat seal under the elastic force of the rubber sleeve.

[0037] The embodiments of this utility model have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on this utility model. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. A double-controlled oil-casing safety valve, comprising a valve body, an inside of the valve body being provided with a valve mechanism, a lower end of the valve body being connected with a packer, characterized in that: A rubber sleeve mandrel is fixed to the outer wall of the valve body, and a rubber sleeve is provided on the outer wall of the rubber sleeve mandrel. The outer wall of the valve body is also provided with an axially movable piston. A pusher is fixed on the outer wall of the piston. The upper end of the pusher can contact the lower end of the rubber tube. The lower end of the piston is connected to a pressure transmission hole that runs through the side wall of the valve body. The abnormal pressure generated in the well is transmitted from the pressure transmission hole to the lower end of the piston, which in turn pushes the piston upward and drives the pusher to squeeze the rubber sleeve upward. After being compressed, the rubber sleeve expands outward to achieve annular sealing.

2. The dual-control downhole safety valve for oil casing as described in claim 1, characterized in that: The lower outer wall of the valve body is provided with a piston outer cylinder, and a piston cavity is formed between the lower outer wall of the valve body and the middle inner wall of the piston outer cylinder. The lower end of the piston is located in the piston cavity; the two ends of the pressure transmission hole are respectively connected to the interior of the valve body and the piston cavity.

3. The dual-control downhole safety valve for oil casing as described in claim 1 or 2, characterized in that: The pressure transmission port is located below the valve plate of the valve mechanism.

4. The dual-control downhole safety valve for oil casing as described in claim 1 or 2, characterized in that: The upper outer wall of the valve body is connected to the upper inner wall of the rubber sleeve core, and / or the outer wall of the piston is connected to the inner wall of the push cylinder by threads, and anti-rotation screws are provided.

5. The dual-control downhole safety valve for oil casing as described in claim 2, characterized in that: The lower outer wall of the valve body is connected to the lower inner wall of the piston outer cylinder by a thread, and an anti-rotation screw is provided.

6. The dual-control downhole safety valve for oil casing as described in claim 1 or 2, characterized in that: The upper end of the piston is located between the upper outer wall of the valve body and the middle inner wall of the rubber sleeve core, and the inner and outer walls of the upper end of the piston form a seal with the upper outer wall of the valve body and the middle inner wall of the rubber sleeve core.

7. The dual-control downhole safety valve for oil casing as described in claim 2 or 5, characterized in that: A seal is formed between the inner and outer walls of the lower end of the piston and the outer wall of the lower end of the valve body and the inner wall of the middle part of the piston outer cylinder.

8. The dual-control downhole safety valve for oil casing as described in claim 1, characterized in that: The valve mechanism includes a valve plate seat, which is rotatably connected to the valve plate via a torsion spring and a pin. It also includes a flow tube that can move axially, the outer wall of the flow tube is connected to the inner wall of the valve body by a spring in a compressed state, and the upper end of the flow tube is connected to the control line. When the control line is pressurized, the pressure pushes the flow tube downward, and the lower end of the flow tube pushes the valve plate open downward; when the pressure is removed, the flow tube returns to its original position under the push of the spring, and the valve plate closes.

9. The dual-control downhole safety valve for oil casing as described in claim 8, characterized in that: The upper end of the valve body is provided with an upward pressure chamber, and the upper end of the flow tube is provided with a piston rod. The piston rod is located in the upward pressure chamber, and the upward pressure chamber is connected to the control pipeline through the upward pressure hole; a seal is formed between the outer wall of the piston rod and the inner wall of the upward pressure chamber.

10. The dual-control downhole safety valve for oil casing as described in claim 9, characterized in that: A seal is formed between the outer wall of the piston rod and the inner wall of the pressure chamber by a V-shaped sealing ring.

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