CN104847306B - A kind of underground rod tube safety valve - Google Patents

Abstract

The invention relates to a downhole rod-pipe safety valve for rod-driven artificial lifting. The upper joint is connected with the upper valve body with threads, the upper valve body is connected with the lower valve body with threads, and the lower valve body is connected with the lower joint with threads. , the outer wall of the upper valve is provided with a boss, the boss is provided with a threaded hole, the threaded hole is connected with the control pipeline joint, the inner wall of the upper valve is covered with a piston, the inner wall of the piston is covered with a compression spring, a return spring, a central tube, and the outer wall of the piston It is sealed with the upper part of the upper valve body and the lower part of the upper valve body, the inner wall of the piston is sealed with the upper part of the outer wall of the central tube, and the lower part of the outer wall of the central tube. The inner wall moves to close or open the sucker rod and tubing annulus. When it is opened, it will not affect the normal production of the oil field, and when it is closed, it can seal the annular passage between the sucker rod and the tubing. The invention solves the problem that the rod drive cannot be lowered into the safety valve through artificial lifting.

Description

A downhole pipe safety valve

technical field

The invention relates to a downhole rod pipe safety valve used for rod drive artificial lifting.

Background technique

Countries around the world are paying more and more attention to environmental protection and safe production. Many countries have detailed laws and regulations on the safe production of oil and gas wells, emphasizing that oil and gas that may spontaneously spray or spill in densely populated areas, important economic areas, oceans and inland waters All wells must be equipped with downhole safety valves. In the production of offshore oilfields, in order to ensure the safety of production, it is required to install a safety valve in the downhole, so that in the event of an accident and the wellhead control fails, the oil outlet channel of the tubing can be closed downhole to ensure the safety of the platform. At present, downhole safety valves are installed in domestic offshore oil and gas wells capable of self-spraying, and more and more onshore oil fields use downhole safety valves in oil and gas wells.

In the current production of offshore oilfields, the safety valves used are only suitable for self-flowing wells and electric submersible pump wells, and can only close the tubing passage. The safety valves for rod-driven artificial lift wells with sucker rods in the tubing are still blank. The existing technology cannot meet the safety production requirements of rod-driven artificial lift in offshore oil fields, and there is a lack of a downhole rod-pipe safety valve, which can close the downhole passage with the sucker rod in the oil pipe.

Contents of the invention

The purpose of the present invention is to solve the problem that the rod-driven artificial lift system cannot be lowered into the safety valve, change the traditional piston structure or the sliding mandrel structure to adjust the opening and closing of the valve plate, and use the spherical rubber core sealing assembly to realize the rod holding Sealing or zero sealing function, especially provide a downhole rod and tube safety valve that can be used in rod-driven artificial lift wells.

In order to achieve the above object, the present invention adopts the following technical solutions: a downhole rod and pipe safety valve is composed of a control pipeline, an upper joint, an upper valve body, a spherical rubber core sealing assembly, a sealing ring, a control pipeline joint, a return spring, a piston, It is composed of central pipe, lower valve body, pressure spring and lower joint; its structural features are: the upper end of the upper joint is provided with a female buckle, which is connected with the oil pipe, and the lower end of the upper joint is provided with a female buckle, which is connected with the upper valve body. It is a cylindrical cylinder, the lower end of the upper valve body is provided with a male buckle, which is connected with the lower valve body, the outer wall of the upper valve body is provided with a boss, and the outer wall of the upper valve body is provided with a threaded hole, and the threaded hole is connected with the control pipeline joint , the control pipeline joint is connected with the control pipeline. There is a step on the upper part of the inner wall of the upper valve body, which can limit the upward stroke of the central pipe. A spherical inner wall is arranged under the upper step of the inner wall of the upper valve body. The spherical inner wall of the upper valve body is in contact with the spherical rubber core sealing assembly. , the spherical rubber core sealing assembly can slide along the spherical inner wall of the upper valve body. There is a step in the middle of the inner wall of the upper valve body. There is a through hole in the upper valve body. On the inner wall of the upper valve, the opening of the other end of the through hole is located under the middle step of the inner wall of the upper valve. The inner cavity of the upper valve is covered with a piston. Ring, the lower part of the inner wall of the upper valve is matched with the lower part of the outer wall of the piston. The lower part of the outer wall of the piston is provided with an annular groove for placing the sealing ring. The piston is a cylindrical cylinder that can slide along the inner wall of the upper valve. The upper end of the piston is fixed with the spherical rubber core seal connection, the middle part of the outer wall of the piston is provided with a step, the height of the middle step of the outer wall of the piston is equal to the height of the middle step of the inner wall of the upper valve, the middle step of the outer wall of the piston is located under the middle step of the inner wall of the upper valve, and the middle step of the outer wall of the piston is connected with the middle step of the inner wall of the upper valve. The outer wall of the piston and the inner wall of the upper valve form a circular column chamber, which communicates with the through hole in the upper valve body. The upper end of the inner wall of the piston is provided with a boss, and a return spring is provided under the boss, and the return spring is sleeved in the piston. There is a boss on the lower part of the inner wall of the piston, and a pressure spring is arranged under the boss. The boss and the outer wall of the central tube are in clearance fit. The inner wall of the boss is provided with an annular groove for placing a sealing ring. There is a through hole on the wall of the piston barrel, and one end of the through hole is connected The middle step of the outer wall of the piston and the middle step of the inner wall of the upper valve, the outer wall of the piston, and the inner wall of the upper valve form a circular column chamber. The other end of the through hole is connected to the inner wall of the piston. It is a cylindrical cylinder, the middle part of the outer wall of the central tube is provided with a boss, and the lower end of the return spring is supported on the boss in the middle part of the outer wall of the central tube. Cooperate with the gap of the inner wall of the piston, the boss in the middle of the outer wall of the central tube is provided with an annular groove, and the sealing ring is placed. The chamber communicates with the through hole on the wall of the piston barrel. There are two steps on the inner wall of the lower valve. The upper step supports the pressure spring and can limit the downward stroke of the piston. The lower end of the outer wall of the central tube is clearance fit, and the inner body of the lower valve body The wall is provided with an annular groove for placing a sealing ring, and the lower end of the lower valve body is provided with a male buckle, which is connected with the lower joint, and the lower end is provided with a male buckle, which is connected with the oil pipe.

The beneficial effects of the present invention are: (1) the safety valve can close the downhole passage of the annular space between the sucker rod and the oil pipe, and solve the problem that the offshore rod drive cannot be lowered into the safety valve by artificial lifting. (2) When the safety valve is opened, a large internal diameter can be formed, which does not affect the normal operation of the downhole sucker rod. (3) When the safety valve is closed, it can realize the function of holding rod seal or zero seal. (4) The safety valve adopts hydraulic drive mode, and the underground control is simple and reliable.

Description of drawings

Fig. 1 is a schematic diagram of the working state of a downhole rod safety valve of the present invention when the well is closed;

Fig. 2 is a schematic diagram of the working state of a downhole rod-pipe safety valve of the present invention during oil production;

Fig. 3 is a partially enlarged view of a downhole rod safety valve of the present invention when the well is closed;

Fig. 4 is a partially enlarged view of a downhole rod-pipe safety valve of the present invention during oil production;

Fig. 5 is a schematic cross-sectional view of a spherical rubber core sealing assembly when a downhole rod safety valve of the present invention is closed;

Fig. 6 is a schematic cross-sectional view of a spherical rubber core sealing assembly during oil production of a downhole rod-pipe safety valve of the present invention;

Figure 7 is an appearance view of the spherical rubber core seal assembly;

In the figure: 1. Control pipeline, 2. Upper joint, 3. Upper valve body, 4. Spherical rubber core sealing assembly, 5. Seal ring, 6. Control pipeline joint, 7. Return spring, 8. Piston, 9. Center Pipe, 10. Sealing ring, 11. Sealing ring, 12. Sealing ring, 13. Lower valve body, 14. Compression spring, 15. Sealing ring, 16. Lower joint, 17. Rubber seal, 18. Elastic frame

Detailed ways

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a downhole rod and pipe safety valve of the present invention includes a control pipeline 1, an upper joint 2, an upper valve body 3, a spherical rubber core sealing assembly 4, a sealing ring 5, Control pipeline joint 6, return spring 7, piston 8, central tube 9, sealing ring 10, sealing ring 11, sealing ring 12, lower valve body 13, compression spring 14, sealing ring 15, lower joint 16; its structural features are: The upper end of the upper joint 2 is provided with a female buckle, which is connected with the oil pipe. The lower end of the upper joint 2 is provided with a female buckle, which is connected with the upper valve body 3. The upper valve body 3 is a cylinder, and the lower end of the upper valve body 3 is provided with a male buckle. , connected with the lower valve body 13, the outer wall of the upper valve body 3 is provided with a boss, the outer wall of the upper valve body 3 is provided with a threaded hole, the threaded hole is connected with the control pipeline joint 6, and the control pipeline joint 6 is connected with the control pipeline 1 connection, the upper part of the upper inner wall of the upper valve body 3 is provided with a step 3a, which can limit the upward stroke of the central tube 9, and the upper inner wall of the upper valve body 3 is provided with a spherical inner wall under the upper step 3a, and the spherical inner wall of the upper valve body 3 is in contact with the spherical rubber core sealing assembly 4, The spherical rubber core sealing assembly 4 can slide along the spherical inner wall of the upper valve body 3. A step 3c is provided in the middle of the inner wall of the upper valve body 3. A through hole 3b is arranged in the upper valve body 3. One end of the through hole 3b is connected to the control pipeline joint 6, and the other end is Connected to the inner wall of the upper valve body 3, the other end opening of the through hole 3b is located under the middle step 3c of the inner wall of the upper valve body 3, the inner cavity of the upper valve body 3 is covered with a piston 8, and the upper part of the upper inner wall of the upper valve body 3 is matched with the upper part of the outer wall of the piston 8. There is an annular groove on the upper part of the outer wall of the piston 8, and the sealing ring 5 is placed. The lower part of the inner wall of the upper valve body 3 is matched with the lower part of the outer wall of the piston 8. The lower part of the outer wall of the piston 8 has an annular groove, and the sealing ring 11 is placed. The piston 8 is a cylinder. It can slide along the inner wall of the upper valve body 3, the upper end of the piston 8 is fixedly connected with the spherical rubber core sealing assembly 4, the middle part of the outer wall of the piston 8 is provided with a step 8b, the height of the middle step 8b of the outer wall of the piston 8 is equal to the height of the middle step 3c of the inner wall of the upper valve body 3, The middle step 8b of the outer wall of the piston 8 is located under the middle step 3c of the inner wall of the upper valve body 3, the middle step 8b of the outer wall of the piston 8, the middle step 3c of the inner wall of the upper valve body 3, the outer wall of the piston 8, and the inner wall of the upper valve body 3 form a circular column chamber 3d , the ring column chamber 3d communicates with the through hole 3b in the upper valve body 3, the upper end of the inner wall of the piston 8 is provided with a boss, and a return spring 7 is arranged under the boss, the return spring 7 is set in the piston 8, and the lower part of the inner wall of the piston 8 is arranged There is a boss 8d, a pressure spring 14 is arranged under the boss 8d, the boss 8d and the outer wall of the central tube 9 have a gap fit, the inner wall of the boss 8d has an annular groove, and a sealing ring 12 is placed, and a through hole 8a is opened on the wall of the piston 8 One end of the through hole 8a is connected to the middle step 8b of the outer wall of the piston 8 and the middle step 3c of the inner wall of the upper valve body 3, the outer wall of the piston 8, and the inner wall of the upper valve body 3. The annular column chamber 3d is formed, and the other end of the through hole 8a is connected to the inner wall of the piston 8, The other end of the through hole 8a opens at the upper end of the boss 8d at the lower part of the inner wall of the piston 8. The central tube 9 is a cylindrical body, and the middle part of the outer wall of the central tube 9 is provided with a boss. The central tube 9 outer wall middle part boss height is equal to the piston 8 inner wall lower boss 8d height, and the middle The boss at the middle part of the outer wall of the core tube 9 fits with the inner wall of the piston 8 in clearance, the boss at the middle part of the outer wall of the center tube 9 is provided with an annular groove, and the seal ring 10 is placed there, the boss at the middle part of the outer wall of the center tube 9 and the lower boss 8d of the inner wall of the piston 8, and the inner wall of the piston 8 1. The outer wall of the central tube 9 forms a circular column chamber 8c, which communicates with the through hole 8a on the cylinder wall of the piston 8, and the inner wall of the lower valve body 13 is provided with two steps, and the upper step 13a supports the compression spring 14 , and can limit the downward stroke of the piston 8, the lower step 13b can limit the downward stroke of the center pipe 9, the inner wall of the lower valve body 13 is matched with the lower end of the outer wall of the central pipe 9, the inner wall of the lower valve body 13 has an annular groove, and the sealing ring 15 is placed. The lower end of the valve body 13 is provided with a male buckle, which is connected with the lower joint 16, and the lower end of the lower joint 16 is provided with a male buckle, which is connected with the oil pipe.

As shown in Figure 2 and Figure 4, when a downhole rod-pipe safety valve of the present invention is in normal production of the oil well, hydraulic oil is passed through the control pipeline 1, and the hydraulic oil enters the upper valve body 3 along the control pipeline 1, and then along the through hole 3b Enter the ring column chamber 3d, then enter the through hole 8a in the piston 8, and finally enter the ring column chamber 8c, the piston 8 descends to the upper step 13a on the inner wall of the lower valve body 13, and the central tube 9 stretches the spherical rubber core sealing assembly 4. Up to the upper step 3a of the inner wall of the upper valve body 3, the spherical rubber core sealing assembly 4 does not have a sealing effect, and the central pipe of the safety valve runs through to ensure the normal oil outlet channel of the oil well production.

As shown in Fig. 1 and Fig. 3, when a downhole rod-pipe safety valve of the present invention is closed, the pressure of the control pipeline 1 is relieved, and the center pipe goes down to the lower step 13b of the inner wall of the lower valve under the elastic force of the return spring, and the piston 8 Move upward under the action of the elastic force of the compression spring 14, push the spherical rubber core sealing assembly 4 to lock the sucker rod, and the oil outlet channel between the sucker rod and the oil pipe is closed to ensure the safety of oil field production.

As shown in Fig. 5, Fig. 6 and Fig. 7, the spherical rubber core sealing assembly 4 of a downhole rod and pipe safety valve of the present invention is composed of a rubber seal 17 and an elastic skeleton 18, and the lower end of the spherical rubber core sealing assembly 4 is a The upper end of the circular column is composed of 12 rubber cores uniformly distributed along the circumferential direction for 360 degrees, and the outer wall surface of the spherical rubber core sealing component 4 is a spherical surface.

The working principle of a downhole rod-pipe safety valve of the present invention is: connect the present invention to the oil pipe, go down to the designed position, and then lower other tools to complete the well, usually down to the position of 200-300 meters downhole, and connect and control pipeline, and connected with the wellhead control device; when a downhole rod safety valve of the present invention needs to be opened, hydraulic oil is passed through the control pipeline 1, and the piston is subjected to the downward hydraulic pressure generated by the two annular column chambers 3b, 8c , the upward elastic force of compression spring 14 and return spring 7, the upward frictional force produced by the outer wall of central tube 9 on piston 8, the upward frictional force produced by the inner wall of upper valve body 3 on piston 8, the hydraulic pressure is greater than the sum of spring elastic force and frictional force , the piston 8 moves downward, the central tube 9 is subjected to upward hydraulic pressure, the upward elastic force of the return spring 7, and the friction force generated by the piston 8 on the outer wall of the central tube 9, the hydraulic pressure is greater than the sum of the spring force and the frictional force, and the central tube 9 moves upward , the stiffness of the return spring 7 is greater than that of the compression spring 14, the piston 8 goes down to the end of the stroke first, that is, the piston 8 is supported on the inner wall step 13a of the lower valve body 13, the central tube 9 continues to go up, and the spherical rubber core seal assembly 4 is stretched to go up At the end of the stroke, that is, at the step 3a on the inner wall of the upper valve body 3, the spherical rubber core sealing assembly 4 expands to the outside of the central pipe 9, and the central pipe of the safety valve runs through. Oil channel; when a downhole rod and pipe safety valve of the present invention needs to be closed in an emergency, the pressure is cut off from the ground, the pressure of the control pipeline 1 is relieved, and the central pipe 9 is subjected to the downward elastic force of the return spring 7 and the spherical rubber core sealing assembly 4. The downward friction force, the upward friction force of the inner wall of the lower valve body 13, the downward elastic force of the return spring 7 is greater than the sum of the upward friction force, the central tube 9 goes down to the end of the stroke, that is, the central tube 9 is supported on the inner wall step of the lower valve body 13 13b, the piston 8 is subjected to the upward elastic force of the compression spring 14, the downward friction force generated by the inner wall of the upper valve body 3, and the friction force exerted by the central tube 9 on the spherical rubber core seal assembly 4, and the upward elastic force of the compression spring 14 is greater than the downward friction force With the sum of the forces, the piston 8 moves upward, driving the spherical rubber core sealing assembly 4 to slide along the spherical inner wall of the upper valve body 3, so as to realize the rod-holding or zero-sealing function.

Claims (2)

1. A downhole rod-pipe safety valve, which includes a control pipeline (1), an upper joint (2), an upper valve body (3), a spherical rubber core sealing assembly (4), a sealing ring (5), a control pipeline joint ( 6), return spring (7), piston (8), central tube (9), sealing ring one (10), sealing ring two (11), sealing ring three (12), lower valve body (13), pressure spring (14), sealing ring four (15), lower joint (16); its structural feature is: the upper end of the upper joint (2) is provided with a box, is connected with the oil pipe, and the lower end of the upper joint (2) is provided with a box, and The upper valve body (3) is connected with each other, the upper valve body (3) is a cylinder body, the lower end of the upper valve body (3) is provided with a male buckle, which is connected with the lower valve body (13), and the outer wall of the upper valve body (3) is provided with a There is a boss, the boss on the outer wall of the upper valve body (3) is provided with a threaded hole, the threaded hole is connected with the control pipeline joint (6), the control pipeline joint (6) is connected with the control pipeline (1), the upper valve body ( 3) There is a step (3a) on the upper part of the inner wall, which can limit the upward stroke of the central tube (9). A spherical inner wall is arranged under the upper step (3a) on the upper inner wall of the upper valve body (3). The spherical inner wall of the upper valve body (3) and the spherical glue The core seal assembly (4) contacts, and the spherical rubber core seal assembly (4) can slide along the spherical inner wall of the upper valve body (3). There is a step (3c) in the middle of the inner wall of the upper valve body (3). A through hole (3b) is provided, one end of the through hole (3b) is connected to the control pipeline joint (6), the other end is connected to the inner wall of the upper valve body (3), and the other end of the through hole (3b) is opened in the middle of the inner wall of the upper valve body (3) Under the step (3c), the inner cavity of the upper valve body (3) is covered with a piston (8), and the upper part of the upper inner wall of the upper valve body (3) is matched with the upper part of the outer wall of the piston (8), and the upper part of the outer wall of the piston (8) is provided with an annular groove , place the sealing ring (5), the lower part of the inner wall of the upper valve body (3) is matched with the lower part of the outer wall of the piston (8), and the lower part of the outer wall of the piston (8) has an annular groove, and the second sealing ring (11) is placed, and the piston (8) is A cylindrical cylinder, which can slide along the inner wall of the upper valve body (3), the upper end of the piston (8) is fixedly connected with the spherical rubber core sealing assembly (4), the middle part of the outer wall of the piston (8) is provided with a step (8b), the piston (8) The height of the step (8b) in the middle of the outer wall is equal to the height of the step (3c) in the middle of the inner wall of the upper valve body (3). (8) The step in the middle of the outer wall (8b), the step in the middle of the inner wall of the upper valve body (3), the outer wall of the piston (8), and the inner wall of the upper valve body (3) form a circular column chamber (3d). The chamber (3d) communicates with the through hole (3b) in the upper valve body (3), the upper end of the inner wall of the piston (8) is provided with a boss, and a return spring (7) is arranged under the boss, and the return spring (7) is sleeved on the piston ( 8), the lower part of the inner wall of the piston (8) is provided with a lower boss (8d), and a pressure spring (14) is arranged under the lower boss (8d), and the lower boss (8d) is in clearance fit with the outer wall of the central tube (9), The inner wall of the lower boss (8d) is provided with an annular groove, and three sealing rings (12) are placed therein. There is a through hole (8a) on the cylinder wall of the plug (8), and one end of the through hole (8a) is connected to the middle step (8b) of the outer wall of the piston (8) and the middle step (3c) of the inner wall of the upper valve body (3), the piston (8) The outer wall and the annular column chamber (3d) formed by the inner wall of the upper valve body (3), the other end of the through hole (8a) is connected to the inner wall of the piston (8), and the other end of the through hole (8a) is opened on the lower part of the inner wall of the piston (8). The upper end of the platform (8d), the central tube (9) is a cylinder, the middle part of the outer wall of the central tube (9) is provided with a boss, the lower end of the reset spring (7) is supported on the boss of the middle part of the outer wall of the central tube (9), and the central tube (9) The height of the boss in the middle of the outer wall is equal to the height of the boss (8d) in the lower part of the inner wall of the piston (8). There is an annular groove, a seal ring one (10) is placed, the middle boss of the outer wall of the central tube (9) and the lower boss (8d) of the inner wall of the piston (8), the inner wall of the piston (8), and the outer wall of the central tube (9) form a ring The column chamber (8c), the circular column chamber (8c) communicates with the through hole (8a) on the cylinder wall of the piston (8), the inner wall of the lower valve body (13) is provided with two steps, and the upper step (13a) bears Support the pressure spring (14), and limit the downward stroke of the piston (8), the lower step (13b) can limit the downward stroke of the central tube (9), and the inner wall of the lower valve body (13) cooperates with the lower end of the outer wall of the central tube (9). The inner wall of the lower valve body (13) is provided with an annular groove for placing four sealing rings (15), and the lower end of the lower valve body (13) is provided with a male buckle, which is connected with the lower joint (16), and the lower end of the lower joint (16) is provided with a male buckle , connected with the tubing; The spherical rubber seal assembly (4) is composed of a rubber seal (17) and an elastic skeleton (18). The lower end of the spherical rubber seal assembly (4) is a ring column, and the upper end is formed by 12 rubber cores along the 360-degree uniform distribution in the circumferential direction, the outer wall of the spherical rubber core seal assembly (4) is a spherical surface, the spherical rubber core seal assembly has stable dynamic sealing, corrosion resistance and fatigue resistance performance, and meets the requirements of oil and gas wells. Through the control pipeline (1 ) is pressurized to move and open, and the oil outlet channel between the sucker rod and the oil pipe is closed through the reset of the pressure relief spring of the control pipeline (1); When the safety valve is opened, the central tube (9) moves upward, the piston (8) drives the spherical rubber core seal assembly (4) downward, the central tube (9) stretches the spherical rubber core seal assembly (4), and the spherical rubber core seal assembly (4) The component (4) does not function as a seal, and the center pipe (9) of the safety valve runs through to ensure the normal oil outlet channel for oil well production; when the safety valve is closed, the center pipe (9) goes down, and the piston (8) drives the spherical rubber core The sealing component (4) moves upward, and the spherical rubber core sealing component (4) moves along the spherical inner wall of the upper valve body (3) to close the rubber core to realize sealing. 2. The downhole rod-pipe safety valve according to claim 1, characterized in that: the upper stroke of the center pipe (9) is limited by the upper step (3a) of the upper valve body (3), and the lower stroke is limited by the lower valve body ( 13) Restricted by the lower step (13b); the downstroke of the piston (8) is restricted by the upper step (13a) of the lower valve body (13), and the upper stroke is restricted by the middle step (3c) of the inner wall of the upper valve body (3).