A rotary device for completion of a branched wellbore

Abstract

The present invention relates to a rotating device for completion of a branch wellbore. It includes a central pipe, an upper housing, a middle housing, a lower housing, a locking sleeve and shear pins. The upper housing, the middle housing and the lower housing are sequentially connected together by threads, forming a cavity and a first trapezoidal groove inside; the inner surface of the middle housing has a second trapezoidal groove along the circumferential direction; an annular outer key protrudes radially on the outer surface of the middle part of the central pipe, and the lower part is divided into a plurality of rectangular grooves; the protrusions at the lower end of the central pipe respectively form a limit fit with the first and second trapezoidal grooves, and its upper end extends outside the cavity; the locking sleeve is connected to the lower housing by shear pins, its upper end extends into the central pipe, and its lower end extends into the lower housing. The present invention is connected between a wall-mounted hanger and a branch wellbore completion string. When the wall-mounted hanger is set, the wall-mounted hanger can rotate independently of the branch wellbore completion string, thereby avoiding damage to the casing buckle of the completion string.

Description

Technical Field

[0001] The present invention relates to a rotating device in the field of downhole tools, particularly a rotating device for completion of branch wellbores. Background Art

[0002] The wall-mounted hanger serves as the mechanical support between the main wellbore and the branch wellbore, playing the role of connecting the main wellbore and the branch wellbore. Its upper part is connected to the main wellbore hanger, the lower part is connected to the completion string of the branch wellbore, and the hook in the middle is hung on the casing windowed in the main wellbore. When the wall-mounted hanger is set and hung, it is necessary to lower the pipe string composed of the main wellbore hanger, the wall-mounted hanger and the completion string of the branch wellbore to a predetermined position through a special feeding tool, and then rotate the pipe string to adjust the angle to hang the hook of the wall-mounted hanger on the casing windowed in the main wellbore. Since the lower part of the wall-mounted hanger is connected to the completion string of the branch wellbore, during the process of rotating and adjusting the pipe string, due to the large friction between the completion string and the open-hole wellbore wall, the casing joints in the completion string are easily damaged. Summary of the Invention

[0003] In order to solve the problem that the casing joints of the completion string in the branch wellbore are easily damaged when the wall-mounted hanger is set and hung, the present invention provides a rotating device for completion of branch wellbores.

[0004] The technical solution of the present invention:

[0005] A rotating device for completion of branch wellbores includes a central tube, an upper housing, a middle housing, a lower housing, a lock sleeve and shear pins. Among them: the upper housing, the middle housing and the lower housing are sequentially connected together to form a cavity and a first trapezoidal groove inside; the inner surface of the middle housing has a second trapezoidal groove along the circumferential direction; the central tube and the lock sleeve are arranged inside the cavity; the lower end of the central tube is evenly divided into a plurality of rectangular grooves along the axial direction, and the protrusions at the lower end of the central tube respectively form a limit fit with the first trapezoidal groove and the second trapezoidal groove, and the upper end of the central tube extends outside the cavity of the upper housing; the lock sleeve is connected to the lower housing through shear pins, its upper end extends into the central tube, and its lower end extends into the lower housing; the lock sleeve is circular tubular, and a step is arranged on the outer surface of the middle section along the axial direction. The upper end surface of the step forms a hydraulic cavity with the inner step of the middle housing, and pressure transmission holes communicating the inside and outside of the lock sleeve are radially arranged on the lock sleeve near the hydraulic cavity. The lower end surface of the step of the lock sleeve forms an axial blocking fit with the inner step of the lower housing.

[0006] The above solution further includes:

[0007] A circular outer key protrudes radially on the outer surface of the middle part of the central tube, and a circular inner key is arranged radially on the inner surface of the middle part of the upper housing. The circular outer key and the circular inner key form an axial sliding and circumferential limit fit.

[0008] The pressure transmission holes are a plurality of evenly distributed on the lock sleeve.

[0009] The protrusions at the lower end of the central pipe are circumferentially distributed along the rectangular groove at the lower end of the central pipe, and the axial sectional shape along the central pipe is trapezoidal.

[0010] The upper end of the central pipe has threads; the circular outer key of the central pipe and the circular inner key of the upper housing are both one or more.

[0011] The beneficial effect of the present invention is that this device is connected between the wall-mounted hanger and the completion string of the branch wellbore. When the wall-mounted hanger is set down and hung, this device can make the wall-mounted hanger rotate independently of the completion string of the branch wellbore, thereby avoiding damage to the casing buckle of the completion string. Description of the Drawings

[0012] Figure 1 It is a schematic structural diagram of a rotary device for completing a branch wellbore according to the present invention;

[0013] Figure 2 is Figure 1 The sectional view at A-A in

[0014] Figure 3 is Figure 1 The sectional view at B-B in

[0015] Figure 4 is Figure 1 The sectional view at C-C in

[0016] Figure 5 is Figure 1 The sectional view at D-D in

[0017] Figure 6 It is a schematic structural diagram of a rotary device for completing a branch wellbore in an unlocked state according to the present invention;

[0018] In the figure, 1. Central pipe, 2. Y-shaped sealing ring, 3. Upper housing, 4. Circular outer key, 5, 6, 13, 15, 19. O-shaped sealing ring, 7. Circular inner key, 8. First trapezoidal groove, 9. Protrusion, 10. Second trapezoidal groove, 11. Middle housing, 12. Pressure transmission hole, 14. Lock sleeve, 16. Lower housing, 17. Hydraulic cavity, 18. Shearing pin. Detailed Description of the Invention

[0019] The following will be further described in detail with reference to the drawings and embodiments.

[0020] Embodiment 1

[0021] A rotary device for completion of a branched wellbore, comprising a central pipe 1, an upper housing 3, a middle housing 11, a lower housing 16, a locking sleeve 14 and shear pins 18, wherein: The upper housing 3, the middle housing 11 and the lower housing 16 are sequentially connected together to form a cavity and a first trapezoidal groove 8 inside; There is a second trapezoidal groove 10 on the inner surface of the middle housing 11 along the circumferential direction; The central pipe 1 and the locking sleeve 14 are arranged inside the cavity; The lower end of the central pipe 1 is axially divided into a plurality of rectangular grooves, and the protrusions 9 at the lower end of the central pipe 1 are respectively in limit fit with the first trapezoidal groove 8 and the second trapezoidal groove 10, and the upper end of the central pipe 1 extends outside the cavity of the upper housing 3; The locking sleeve 14 is connected to the lower housing 16 by shear pins 18, its upper end extends inside the central pipe 1, and its lower end extends inside the lower housing 16; The locking sleeve 14 is tubular, and there is a step on the outer surface of the middle section along the axial direction. The upper end face of the step forms a hydraulic cavity 17 with the inner step of the middle housing 11. Pressure transmission holes 12 communicating with the inside and outside of the locking sleeve 14 are radially arranged on the locking sleeve 14 near the hydraulic cavity. The lower end face of the step of the locking sleeve 14 forms an axial blocking fit with the inner step of the lower housing 16.

[0022] Embodiment 2

[0023] Based on the above Embodiment 1, it further includes:

[0024] A circular outer key 4 protrudes radially from the outer surface of the middle part of the central pipe 1, and a circular inner key 7 is arranged radially on the inner surface of the middle part of the upper housing 3. The circular outer key 4 and the circular inner key 7 form an axially sliding and circumferentially limiting fit.

[0025] The pressure transmission holes 12 are multiple and evenly distributed on the locking sleeve 14.

[0026] The protrusions 9 at the lower end of the central pipe 1 are circumferentially distributed along the rectangular grooves at the lower end of the central pipe 1, and the axial cross-sectional shape along the central pipe 1 is trapezoidal.

[0027] The upper end of the central pipe 1 has a thread; The circular outer key 4 of the central pipe 1 and the circular inner key 7 of the upper housing 3 are both one or more

[0028] Typical Embodiment 3

[0029] Figure 1It is a rotary device for branch well completion, which is composed of a central pipe 1, an upper housing 3, a middle housing 11, a lower housing 16, a locking sleeve 14, shear pins 18, Y-shaped sealing rings 2 and O-shaped sealing rings 5, 6, 13, 15, 19. The upper housing 3, the middle housing 11 and the lower housing 16 are sequentially connected together by threads, forming a cavity and a first trapezoidal groove 8 inside; an O-shaped sealing ring 5 is provided at the connection between the upper housing 3 and the middle housing 11; an O-shaped sealing ring 19 is provided at the connection between the middle housing 11 and the lower housing 16; a second trapezoidal groove 10 is provided on the inner surface of the middle housing 11 along the circumferential direction; the central pipe 1 and the locking sleeve 14 are arranged inside the cavity; the protrusion 9 at the lower end of the central pipe 1 is located in the second trapezoidal groove 10, and its upper end extends outside the cavity of the upper housing 3 and is provided with threads; the locking sleeve 14 is circular tubular, and its outer surface is "convex" along the axial direction and is connected to the lower housing 16 by shear pins 18. Its upper end extends into the central pipe 1, and its lower end extends into the lower housing 16; O-shaped sealing rings 6 and 13 are provided between the locking sleeve 14 and the middle housing 11, and an O-shaped sealing ring 15 is provided between the locking sleeve 14 and the lower housing 16.

[0030] Figure 2 As shown, there is 1 circular outer key 4 protruding radially on the outer surface of the middle part of the central pipe 1, and there is 1 circular inner key 7 protruding radially on the inner surface of the middle part of the upper housing 3, and the circular outer key 4 and the circular inner key 7 are in an engaged state.

[0031] Figure 3 As shown, the lower part of the central pipe 1 is divided into n by a positive integer n number of rectangular grooves into

[0032] Figure 4 As shown, there are 4 pressure transmission holes 12 communicating with the inside and outside of the locking sleeve 14 arranged circumferentially near the upper shoulder of the locking sleeve 14.

[0033] Figure 5 As shown, the lower end of the locking sleeve 14 is connected to the lower housing 16 by 4 shear pins 18.

[0034] Figure 6 As shown is a schematic structural diagram of a rotary device for branch well completion in an unlocked state. The shear pins 18 are cut off, the lower shoulder of the locking sleeve 14 contacts the lower housing 16, the protrusion 9 at the lower end of the central pipe 1 is located in the first trapezoidal groove 8, and the circular outer key 4 and the circular inner key 7 are separated. The central pipe 1 and its upper pipe string can rotate independently of the lower pipe string of the rotary device.

[0035] The rotary device for completing a branch wellbore is used during the completion process of a branch wellbore. The string structure from top to bottom is: drill pipe + running tool + main wellbore hanger + wall-mounted hanger + a rotary device for completing a branch wellbore + branch wellbore completion string (including wellbore isolation valve). During construction, the string is slowly lowered into the well. When the wall-mounted hanger reaches the connection between the main wellbore and the branch wellbore, the lowering is stopped. A pressure-holding ball is dropped into the string from the wellhead, and the pump at the wellhead is started to apply pressure. When the pressure-holding ball reaches the wellbore isolation valve, the pressure-holding ball seals the inside and outside of the string, and pressure builds up inside the string. The hydraulic pressure is transmitted through the pressure transmission hole 12 into the hydraulic chamber 17. When the pressure reaches a certain value, the shear pin 18 is cut, and the lock sleeve 14 moves downward until it stops moving when the lower step of the lock sleeve 14 contacts the lower housing 16. Then, the pump at the wellhead is stopped, and the string is lifted. When the lower protrusion 9 of the central pipe 1 moves from the second trapezoidal groove 10 to the first trapezoidal groove 8, the hook load at the wellhead will increase, and the lifting of the string is stopped. At this time, the rotary device for completing a branch wellbore is in the unlocked state. Figure 6 As shown, the string above the central pipe 1 can rotate independently of the string below the rotary device for completing a branch wellbore, facilitating the setting of the wall-mounted hanger and avoiding damage to the casing threads of the completion string in the branch wellbore.

Claims

1. A rotary device for completion of a branch wellbore, comprising a central pipe (1), an upper housing (3), a middle housing (11), a lower housing (16), a locking sleeve (14) and a shear pin (18), characterized in that: The upper housing (3), the middle housing (11), and the lower housing (16) are connected together in sequence, forming a cavity and a first trapezoidal groove (8) inside; the inner surface of the middle housing (11) has a second trapezoidal groove (10) along the circumference; the central tube (1) and the lock sleeve (14) are arranged inside the cavity; the lower end of the central tube (1) is evenly divided into a plurality of rectangular grooves along the axis, and the protrusions (9) at the lower end of the central tube (1) are respectively in limit fit with the first trapezoidal groove (8) and the second trapezoidal groove (10), and the upper end of the central tube (1) extends outside the cavity of the upper housing (3); the lock sleeve (14) is connected to the lower housing (16) by a shear pin (18), its upper end extends inside the central tube (1), and its lower end extends inside the lower housing (16); the lock sleeve (14) is circular tubular, and there is a step on the outer surface of the middle section along the axis. The upper end surface of the step forms a hydraulic cavity (17) with the inner step of the middle housing (11). Pressure transmission holes (12) communicating the inside and outside of the lock sleeve (14) are radially arranged on the lock sleeve (14) near the hydraulic cavity. The lower end surface of the step of the lock sleeve (14) forms an axial blocking fit with the inner step of the lower housing (16); a circular outer key (4) protrudes radially on the outer surface of the middle part of the central tube (1), and a circular inner key (7) is arranged radially on the inner surface of the middle part of the upper housing (3). The circular outer key (4) and the circular inner key (7) form an axial sliding and circumferential limit fit.

2. The rotary device for branch well completion according to claim 1, characterized in that: The pressure transmission holes (12) are multiple and are evenly distributed on the lock sleeve (14).

3. The rotary device for branch well completion according to claim 2, characterized in that: The protrusions (9) at the lower end of the central tube (1) are circumferentially distributed along the rectangular grooves at the lower end of the central tube (1), and the axial cross-sectional shape along the central tube (1) is trapezoidal.

4. The rotary device for branch well completion according to claim 3, characterized in that: The upper end of the central tube (1) has a thread; the circular outer key (4) of the central tube (1) and the circular inner key (7) of the upper housing (3) are both one or more.

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