Open hole packer for sidetracking well

Abstract

The utility model relates to an open hole packer for sidetracking wells, which comprises a central tube, a rubber sleeve, a guide ring, a piston, a shearing seat and a lower ball head mechanism, and the rubber sleeve and the guide ring are sleeved on the outer circle of the lower end of the central tube; the upper end of the lower center rod is arranged in the cavity of the piston, and the lower end extends out of the cavity of the piston and is fixedly connected with the lower ball head mechanism; the lower end of the upper center rod extends into the cavity of the piston and is fixedly connected with the upper end of the lower center rod, the upper end of the upper center rod is fixedly connected with the lower end of the upper ball head mechanism, and the upper end of the upper ball head mechanism is fixedly connected with the lower end of the center pipe. A compression type rubber sleeve and a rotatable ball head (an upper ball head mechanism and a lower ball head mechanism) are adopted, sealing of an open hole well can be completed at the same time through a small-radius well hole, the packer and a drill bit and a drilling tool are used at a time, and after well drilling is completed, pressure building and setting of the packer can be directly conducted for fracturing construction. According to the utility model, drilling and fracturing construction can be completed by one-time drilling while small-radius drilling is realized in a sidetracking well, and the construction efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to a downhole tool for petroleum development, in particular to an open hole packer for ultra-short radius side drilling. Background Art

[0002] At present, the underground conditions of developed blocks in domestic old oil fields are becoming increasingly complex, with scattered distribution of remaining oil, weak foundation for stable production, increasing number of flooded wells, casing damage and casing change wells, and increasing difficulty in resuming production. In order to solve the development problems and focus on stable production of old oil fields, it is necessary to adopt side drilling well construction, which has a large side drilling radius and cannot accurately reach the target formation. At the same time, fracturing construction is required in the later stage, and a new fracturing string must be added, which has a long construction period and high cost. Utility Model Content

[0003] The utility model provides an open hole packer for side drilling wells, which adopts a compression rubber cylinder and a rotatable ball head, can pass through a wellbore with a small radius, and complete the isolation of the open hole well at the same time.

[0004] The technical solution adopted by the utility model is: an open hole packer for side drilling, characterized in that it comprises a center pipe, a rubber tube, a guide ring, a piston, a shear seat and a lower ball head mechanism arranged from top to bottom, the upper end of the center pipe is fixedly connected to the drill pipe, and the outer circle of the lower end is sequentially sleeved with a rubber tube and a guide ring from top to bottom; the upper end of the rubber tube abuts against the stepped surface of the center pipe, and the lower end abuts against the upper end of the guide ring; the lower end of the guide ring is in spherical contact with the upper end of the piston, the piston is connected to the shear seat through a shear pin, and the shear seat is fixedly arranged on the outer circle wall of the lower center rod;

[0005] The upper end of the lower center rod is arranged in the cavity of the piston, and the lower end extends out of the cavity of the piston and is fixedly connected to the lower ball head mechanism; the lower end of the upper center rod extends into the cavity of the piston and is fixedly connected to the upper end of the lower center rod, and the lower end of the upper center rod is provided with a pressure transmission hole connecting the central flow channel and the piston cavity; the upper end of the upper center rod is fixedly connected to the lower end of the upper ball head mechanism, and the upper end of the upper ball head mechanism is fixedly connected to the lower end of the center tube.

[0006] Preferably, the upper ball head mechanism includes an upper ball head seat, an upper ball head connecting rod and an upper ball head, the inner wall of the upper end of the upper ball head seat is fixedly connected to the outer wall of the lower end of the center tube, the inner wall of the lower end of the upper ball head seat is in cooperative contact with the spherical surface of the upper end of the upper ball head, and the lower end of the upper ball head is fixedly connected to the upper end of the upper center rod; the outer wall of the lower end of the upper ball head seat is fixedly connected to the inner wall of the upper end of the upper ball head connecting rod, the inner wall of the lower end of the upper ball head connecting rod is circumferentially provided with a plurality of semicircular long grooves, the upper spherical surface of the upper ball head is provided with a plurality of waist-shaped grooves corresponding to the semicircular long grooves, and upper steel balls are provided in the semicircular long grooves and the corresponding waist-shaped grooves.

[0007] Preferably, the upper end of the upper ball head is spherical, the lower end is cylindrical, and a flow channel is axially penetrated in the middle.

[0008] Preferably, the upper steel ball rolls in the waist-shaped groove on the upper spherical surface of the upper ball head and the semicircular long groove corresponding to the lower end of the upper ball head connecting rod, and the upper ball head and the upper ball head connecting rod can rotate up and down 20°.

[0009] Preferably, the lower ball head mechanism includes a lower ball head seat, a lower steel ball, a lower ball head connecting rod and a lower ball head, the inner wall of the upper end of the lower ball head seat is fixedly connected to the outer wall of the lower end of the lower center rod, the inner wall of the lower end of the lower ball head seat is in cooperative contact with the spherical surface of the upper end of the lower ball head, and the lower end of the lower ball head is fixedly connected to the drill tool; the outer wall of the lower end of the lower ball head seat is fixedly connected to the inner wall of the upper end of the lower ball head connecting rod, the inner wall of the lower end of the lower ball head connecting rod is circumferentially provided with a plurality of semicircular long grooves, the spherical surface of the upper end of the lower ball head is provided with a plurality of waist-shaped grooves corresponding to the semicircular long grooves, and lower steel balls are arranged in the semicircular long grooves and the corresponding waist-shaped grooves.

[0010] Preferably, the upper end of the lower ball head is spherical, the lower end is cylindrical, and a flow channel is axially penetrated in the middle.

[0011] Preferably, the lower steel ball rolls in the waist-shaped groove on the upper spherical surface of the lower ball head and the semicircular long groove corresponding to the lower end of the lower ball head connecting rod, and the lower ball head and the lower ball head connecting rod can rotate up and down 20°.

[0012] Preferably, the end surface of the guide ring in contact with the rubber cylinder and the step surface in contact with the rubber cylinder are both 30° conical surfaces.

[0013] Preferably, the mating surface between the lower end of the guide ring and the upper end of the piston is an outer convex spherical surface, and the mating surface between the upper end of the piston is an inner concave spherical surface; the outer convex spherical surface and the inner concave spherical surface cooperate so that the guide ring and the piston can rotate up and down 20°.

[0014] The beneficial effects achieved by the utility model are: using a compression rubber cylinder and a rotatable ball head (upper ball head mechanism and lower ball head mechanism), it can pass through a small radius wellbore and complete the isolation of an open hole well at the same time (the open hole packer has an outer diameter of 120mm, a bendable length of 400mm, and can withstand a pressure of 50MPa in a 160mm open hole well). It is used in one trip with the drill bit and drilling tools, and after drilling the well, the pressure can be directly held to seal the packer for fracturing construction. The utility model can achieve small radius drilling in the side drilling well and complete drilling and fracturing construction in one trip, greatly improving the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model;

[0016] Figure 2 It is a schematic diagram of the structure of half of the guide ring;

[0017] Figure 3Schematic diagram of the structure of the upper ball head;

[0018] Figure 4 It is a schematic diagram of the structure of half of the upper ball head connecting rod;

[0019] In the figure: 1. center tube; 2. rubber cylinder; 3. guide ring; 4. upper ball head seat; 5. upper steel ball; 6. upper ball head connecting rod; 61. semicircular long groove; 7. upper ball head; 71. waist-shaped groove; 8. upper center rod; 9. piston; 10. lower center rod; 11. shear pin; 12. shear seat; 13. lower ball head seat; 14. lower ball head connecting rod; 15. lower steel ball; 16. lower ball head. DETAILED DESCRIPTION

[0020] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] like Figure 1-4 As shown, the utility model is a kind of open hole packer for side drilling, comprising a center pipe 1, a rubber tube 2, a guide ring 3, a piston 9, a shear seat 12 and a lower ball head mechanism arranged from top to bottom. The upper end of the center pipe 1 is fixedly connected with the drill pipe, and the outer circle of the lower end is sequentially sleeved with a rubber tube 2 and a guide ring 3 from top to bottom; the upper end of the rubber tube 2 abuts against the stepped surface of the center pipe 1, and the lower end abuts against the upper end of the guide ring 3; the lower end of the guide ring 3 is in spherical contact with the upper end of the piston 9, and the piston 9 is connected with the shear seat 12 through the shear pin 11. Then, the shear seat 12 is fixedly arranged on the outer circular wall of the lower center rod 10; the upper end of the lower center rod 10 is arranged in the cavity of the piston 9, and the lower end extends out of the cavity of the piston 9 and is fixedly connected to the lower ball head mechanism; the lower end of the upper center rod 8 extends into the cavity of the piston 9 and is fixedly connected to the upper end of the lower center rod 10, and the lower end of the upper center rod 8 is provided with a pressure transmission hole connecting the central flow channel and the piston cavity; the upper end of the upper center rod 8 is fixedly connected to the lower end of the upper ball head mechanism, and the upper end of the upper ball head mechanism is fixedly connected to the lower end of the center tube 1.

[0022] In this embodiment, the upper ball head mechanism and the lower ball head mechanism have the same structure. The upper ball head mechanism is arranged between the upper center rod 8 and the center tube 1, and is inside the cavity formed by the guide ring 3 and the piston 9; the lower ball head mechanism is arranged at the lower end of the lower center rod 10.

[0023] In this embodiment, the upper ball head mechanism includes an upper ball head seat 4, an upper ball head connecting rod 6 and an upper ball head 7. The inner wall of the upper end of the upper ball head seat 4 is fixedly connected to the outer wall of the lower end of the center tube 1, the inner wall of the lower end of the upper ball head seat 4 is in cooperative contact with the spherical surface of the upper end of the upper ball head 7, and the lower end of the upper ball head 7 is fixedly connected to the upper end of the upper center rod 8; the outer wall of the lower end of the upper ball head seat 4 is fixedly connected to the inner wall of the upper end of the upper ball head connecting rod 6, and the inner wall of the lower end of the upper ball head connecting rod 6 is circumferentially provided with a plurality of semicircular long grooves 61, and the upper spherical surface of the upper ball head 7 is provided with a plurality of waist-shaped grooves 71 corresponding to the semicircular long grooves 61, and each semicircular long groove 61 and the corresponding waist-shaped groove 71 are provided with two upper steel balls 5. The upper steel ball 5 rolls in the waist-shaped groove 71 on the upper spherical surface of the upper ball head 7 and the corresponding semicircular long groove 61 at the lower end of the upper ball head connecting rod 6. The upper ball head 7 and the upper ball head connecting rod 6 can rotate 20° up and down. The upper steel ball 5 plays an anti-twist effect (with a torsion resistance of 20000Nm) and reduces friction resistance for up and down rotation.

[0024] In this embodiment, the upper end of the upper ball head 7 is spherical, the lower end is cylindrical, and a flow channel is provided in the middle along the axial direction. Waist-shaped grooves 71 are provided at the upper end of the spherical shape, and there are 12 waist-shaped grooves 71 in total. The corresponding semicircular long grooves 61 on the upper ball head connecting rod 6 are also provided at 12 locations in total. The lower end surface of the upper ball head connecting rod 6 is a concave spherical surface, which contacts and cooperates with the spherical surface of the upper ball head 7, which can effectively rotate and press the O-ring to ensure sealing.

[0025] In this embodiment, the lower ball head mechanism has the same structure as the upper ball head mechanism, including a lower ball head seat 13, a lower steel ball 15, a lower ball head connecting rod 14 and a lower ball head 16. The inner wall of the upper end of the lower ball head seat 13 is fixedly connected to the outer wall of the lower end of the lower center rod 10, the inner wall of the lower end of the lower ball head seat 13 is in mating contact with the spherical surface of the upper end of the lower ball head 16, and the lower end of the lower ball head 16 is fixedly connected to the drill tool; the outer wall of the lower end of the lower ball head seat 13 is fixedly connected to the inner wall of the upper end of the lower ball head connecting rod 14, and the inner wall of the lower end of the lower ball head connecting rod 14 is circumferentially provided with a plurality of semicircular long grooves 61, and the upper spherical surface of the lower ball head 16 is provided with a plurality of waist-shaped grooves 71 corresponding to the semicircular long grooves, and the lower steel ball 15 is arranged in the semicircular long grooves 61 and the corresponding waist-shaped grooves 71. Two lower steel balls 15 are provided in each semicircular long groove 61 and the corresponding waist-shaped groove 71; the lower steel balls 15 roll in the waist-shaped groove 71 on the upper spherical surface of the lower ball head 16 and the semicircular long groove 61 corresponding to the lower end of the lower ball head connecting rod 14, and the lower ball head 16 and the lower ball head connecting rod 14 can rotate up and down by 20°. The lower steel balls 15 play an anti-twist role (with a torsion resistance of 20000Nm) and reduce friction resistance for up and down rotation.

[0026] In this embodiment, the upper end of the lower ball head 16 is spherical, the lower end is cylindrical, and a flow channel is provided in the middle along the axial direction. Waist-shaped grooves 71 are provided at the upper end of the sphere, and there are 12 waist-shaped grooves 71 in total. The corresponding semicircular long grooves 61 on the lower ball head connecting rod 14 are also provided at 12 locations in total. The lower end surface of the lower ball head connecting rod 14 is a concave spherical surface, which contacts and cooperates with the spherical surface of the lower ball head 16, which can effectively rotate and press the O-ring to ensure sealing.

[0027] In this embodiment, the end surface of the guide ring 3 in contact with the rubber tube 2, and the stepped surface of the center tube 1 in contact with the rubber tube 2 are both 30° conical surfaces, which can prevent the rubber tube from being squeezed out; the mating surface between the lower end of the guide ring 3 and the upper end of the piston 9 is an outer convex spherical surface 31, and the mating surface between the upper end of the piston 9 is an inner concave spherical surface; the outer convex spherical surface 31 and the inner concave spherical surface cooperate so that the guide ring 3 and the piston 9 can rotate up and down 20°, which is convenient for the sealer to pass through a small radius wellbore.

[0028] In this embodiment, there are two O-ring grooves in the middle of the piston 9, and four threaded holes are provided at the connection between the outer circle of the lower end and the shear seat 12. Shear pins 11 are installed in the threaded holes, which can effectively prevent the packer from being set prematurely. The starting force value of the shear pin 11 is 10MPa, and the shear force value can be adjusted according to the operation requirements.

[0029] In this embodiment, the rubber cylinder 2 adopts a combined structure of a slit back ring and three rubber cylinders. The back rings at the upper and lower ends of the rubber cylinder each have a 15° cone surface that cooperates with the guide ring 3. It can seal a 160mm wellbore with an outer diameter of 120mm, with a pressure resistance of 50MPa and a temperature resistance of 177°C.

[0030] The lower end of the ultra-short radius open hole packer of the utility model is connected to the drilling tool and the drill bit, and the upper end is connected to the drill rod. When passing through the ultra-short radius wellbore, the upper ball head 7 and the upper ball head connecting rod 6, the lower ball head 16 and the lower ball head connecting rod 14, and the guide ring 3 and the piston 10 can each rotate 20°, and the tool outer diameter of 120mm can easily pass through the short radius wellbore of 160mm. After passing through the short radius wellbore, the drill bit and the packer are drilled together, wherein the upper ball head 7, the upper ball head connecting rod 6 and the upper steel ball 5 combination can resist 20000Nm Torque, providing anti-rotation torque for the drill; after drilling to the predetermined layer, by increasing the displacement and holding the pressure to the starting force value of 10MPa, the hydraulic pressure enters the internal cavity of the piston 9 through the pressure transmission hole of the upper center rod 8, the shear pin 11 is sheared off, and the piston 9 moves upward under the pressure, and transmits the thrust to the guide ring 3 through the spherical surface. The guide ring 3 moves upward to squeeze the rubber cylinder 2 to complete the setting, and the setting is set in a 160mm open hole well; at this time, the formation can be fracturing by increasing the displacement and pressure. After the fracturing construction is completed, the packer can be automatically unsealed by pressure relief. At the same time, the tool can be lifted to other layers to perform another fracturing operation on the formation.

[0031] It should be noted that the description of the above technical solution is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solution set forth herein. On the contrary, providing these descriptions will make the disclosure of the utility model thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the utility model is limited only by the scope of the claims.

[0032] Finally, it should be pointed out that the above embodiments are only representative examples of the present utility model. Obviously, the present utility model is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model shall be considered to belong to the protection scope of the present utility model.

Claims

1. An open hole packer for side drilling, characterized in that: It includes a center tube, a rubber cylinder, a guide ring, a piston, a shear seat and a lower ball head mechanism arranged from top to bottom, the upper end of the center tube is fixedly connected to the drill rod, and the outer circle of the lower end is sleeved with a rubber cylinder and a guide ring in sequence from top to bottom; the upper end of the rubber cylinder abuts against the stepped surface of the center tube, and the lower end abuts against the upper end of the guide ring; the lower end of the guide ring is in spherical contact with the upper end of the piston, the piston is connected to the shear seat through a shear pin, and the shear seat is fixedly arranged on the outer circle wall of the lower center rod; The upper end of the lower center rod is arranged in the cavity of the piston, and the lower end extends out of the cavity of the piston and is fixedly connected to the lower ball head mechanism; the lower end of the upper center rod extends into the cavity of the piston and is fixedly connected to the upper end of the lower center rod, and the lower end of the upper center rod is provided with a pressure transmission hole connecting the central flow channel and the piston cavity; the upper end of the upper center rod is fixedly connected to the lower end of the upper ball head mechanism, and the upper end of the upper ball head mechanism is fixedly connected to the lower end of the center tube.

2. The open hole packer for side drilling according to claim 1, characterized in that: The upper ball head mechanism includes an upper ball head seat, an upper ball head connecting rod and an upper ball head, the inner wall of the upper end of the upper ball head seat is fixedly connected to the outer wall of the lower end of the center tube, the inner wall of the lower end of the upper ball head seat is in cooperative contact with the spherical surface of the upper end of the upper ball head, and the lower end of the upper ball head is fixedly connected to the upper end of the upper center rod; the outer wall of the lower end of the upper ball head seat is fixedly connected to the inner wall of the upper end of the upper ball head connecting rod, the inner wall of the lower end of the upper ball head connecting rod is circumferentially provided with a plurality of semicircular long grooves, and the spherical surface of the upper end of the upper ball head is provided with a plurality of waist-shaped grooves corresponding to the semicircular long grooves, and upper steel balls are provided in the semicircular long grooves and the corresponding waist-shaped grooves.

3. The open hole packer for side drilling according to claim 2, characterized in that: The upper end of the upper ball head is spherical, the lower end is cylindrical, and a flow channel is axially penetrated in the middle.

4. The open hole packer for side drilling according to claim 2, characterized in that: The upper steel ball rolls in the waist-shaped groove on the upper spherical surface of the upper ball head and the semicircular long groove corresponding to the lower end of the upper ball head connecting rod. The upper ball head and the upper ball head connecting rod can rotate up and down by 20 degrees.

5. The open hole packer for side drilling according to claim 1, characterized in that: The lower ball head mechanism comprises a lower ball head seat, a lower steel ball, a lower ball head connecting rod and a lower ball head, the inner wall of the upper end of the lower ball head seat is fixedly connected to the outer wall of the lower end of the lower center rod, the inner wall of the lower end of the lower ball head seat is in cooperative contact with the spherical surface of the upper end of the lower ball head, and the lower end of the lower ball head is fixedly connected to the drill tool; the outer wall of the lower end of the lower ball head seat is fixedly connected to the inner wall of the upper end of the lower ball head connecting rod, the inner wall of the lower end of the lower ball head connecting rod is circumferentially provided with a plurality of semicircular long grooves, the spherical surface of the upper end of the lower ball head is provided with a plurality of waist-shaped grooves corresponding to the semicircular long grooves, and lower steel balls are arranged in the semicircular long grooves and the corresponding waist-shaped grooves.

6. An open hole packer for side drilling according to claim 5, characterized in that: The upper end of the lower ball head is spherical, the lower end is cylindrical, and a flow channel is axially penetrated in the middle.

7. The open hole packer for side drilling according to claim 5, characterized in that: The lower steel ball rolls in the waist-shaped groove on the upper spherical surface of the lower ball head and the semicircular long groove corresponding to the lower end of the lower ball head connecting rod. The lower ball head and the lower ball head connecting rod can rotate up and down by 20 degrees.

8. The open hole packer for side drilling according to claim 1, characterized in that: The end surface of the guide ring in contact with the rubber cylinder and the step surface of the center tube in contact with the rubber cylinder are both 30° conical surfaces.

9. The open hole packer for side drilling according to claim 1, characterized in that: The matching surface between the lower end of the guide ring and the upper end of the piston is an outer convex spherical surface, and the matching surface between the upper end of the piston is an inner concave spherical surface; the matching between the outer convex spherical surface and the inner concave spherical surface enables the guide ring and the piston to rotate up and down 20°.

Images