Downhole apparatus

Abstract

A downhole apparatus comprises a housing, a seat mounted in the housing and configured to receive an object such that the object may engage and axially move the seat to operate the downhole apparatus, and a moveable barrier located on one axial side of the seat such that when an object is engaged with the seat a volume is defined between the object and the moveable barrier, wherein the moveable barrier permits said volume to be moved within the apparatus to allow the object to axially move the seat.

Claims

1. A downhole apparatus, comprising: a housing; a seat mounted in the housing and configured to receive an object such that the object may engage and axially move the seat to operate the downhole apparatus; and a moveable barrier located on one axial side of the seat such that when the object is engaged with the seat a volume is defined between the object and the moveable barrier, wherein the moveable barrier permits said volume to be moved within the downhole apparatus to allow the object to axially move the seat; the moveable barrier defining a sealed barrier so as to permit movement of the moveable barrier while preventing fluid flow through the housing, wherein the downhole apparatus is a tubing hanger plug.

2. The downhole apparatus according to claim 1, comprising a valve, wherein the valve is reconfigurable at least from a closed position to an open position upon axial movement of the seat.

3. The downhole apparatus according to claim 1, comprising a valve member, wherein movement of the seat causes corresponding movement of the valve member.

4. The downhole apparatus according to claim 3, wherein the valve member and the seat are integrally formed.

5. The downhole apparatus according to claim 3, wherein the valve member comprises a valve sleeve.

6. The downhole apparatus according to claim 3, wherein the valve member is comprised of multiple parts.

7. The downhole apparatus according to claim 3, wherein the housing defines at least one flow port in a wall thereof, wherein the valve member is configured to initially close said at least one flow port and be axially moved by the seat to cause said at least one flow port to open.

8. The downhole apparatus according to claim 7, wherein the at least one flow port is openable to provide pressure equalization across the downhole apparatus.

9. The downhole apparatus according to claim 1, wherein the seat comprises an object engaging surface.

10. The downhole apparatus according to claim 1, wherein the seat is moveable between a closed position, an open position and a plurality of intermediate positions between the closed and open positions.

11. The downhole apparatus according to claim 1, comprising a latching mechanism for latching the seat within the housing in at least one position.

12. The downhole apparatus according to claim 1, wherein the moveable barrier comprises a piston member axially moveable within the housing.

13. The downhole apparatus according to claim 1, wherein the moveable barrier is biased in one axial direction by a biasing mechanism, and movement of the moveable barrier in the other axial direction against the biasing member is limited by the structure of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a cross-sectional view of a downhole apparatus in a first configuration; and

(3) FIG. 2 is a cross-sectional view of the downhole apparatus of FIG. 1 in a second configuration.

(4) FIG. 3A is a cross sectional view of a second example of a downhole apparatus.

(5) FIG. 3B is a cross-sectional view along section D-D of FIG. 3A.

(6) FIG. 4 is a cross-sectional view of the downhole apparatus of FIG. 3A and FIG. 3B in a second configuration.

(7) FIG. 5 is a cross-sectional view of a third example of a downhole apparatus.

(8) FIG. 6 is a cross-sectional view of a the downhole apparatus of FIG. 5 in a second configuration.

(9) FIG. 7 is an illustration of an application of the downhole apparatus shown in FIGS. 3A, 3B and 4.

DETAILED DESCRIPTION OF THE DRAWINGS

(10) Aspects of the present disclosure relate to a downhole apparatus and method of use. In some examples the downhole apparatus may be provided in the form of a tubing hanger plug. The exemplary description below relates to such an example tubing hanger plug.

(11) Reference is first made to FIG. 1 in which a tubing hanger plug, generally identified by reference numeral 10 is shown. The tubing hanger plug 10 comprises a housing 12 which includes a number of fluid ports 14. A valve member in the form of a valve sleeve 16 is mounted within the housing 12 and in the initial configuration of FIG. 1 closes the fluid ports 14. O-ring seals 18 provide sealing between the valve sleeve 16 and housing 12.

(12) One axial end, which may be defined as an upper end of the valve sleeve 16 and may form an uphole surface according to the present disclosure, defines a seat 20 which functions to be engaged by a ball 22 which has been dropped from surface. Although a ball is described and illustrated, any equivalent object, such as a dart, may alternatively be used. The seat 20 includes bypass ports 23 which facilitate fluid to bypass the ball 22 when engaged with the seat 20.

(13) An opposite end of the valve sleeve 16 includes a latching structure in the form of a collet 24 which in the configuration shown in FIG. 1 is latched into a first annular recess 26 formed in the housing 12.

(14) The tubing hanger plug 10 also includes a barrier member in the form of a floating piston 28 which is located below the valve sleeve 16. The floating piston 28 is sealed with the housing 12 via O-ring seals 30, and includes a closed or capped end 32, thus providing isolation above and below said floating piston 28, as might be required in a tubing hanger plug 10. That is, the floating piston 28 prevents flow along or through the housing 12. The floating piston 28 therefore may function as a primary internal barrier to fluid flow into the apparatus (i.e. into the apparatus uphole of the floating piston 28) from an external location. In the example illustrated the floating piston 28 is biased in an upward direction by a spring 29.

(15) When the ball 22 is engaged with the seat 20, a trapped volume 34 is defined axially between the ball 22 and the floating piston 28.

(16) In use, the ball 22 will act on the seat 20, and thus valve sleeve 16 and, as shown in FIG. 2, will cause the valve sleeve 16 to shift axially and open the ports 14, thus providing pressure equalizations across the tubing hanger plug 10.

(17) Axial shifting of the ball 22 and valve seat 20 will cause the floating piston 28 to also move axially, thus permitting the trapped volume 34 to also move. In this respect, force applied via the ball will be transferred to the floating piston 28 via the trapped fluid. Accordingly, the floating piston 28 may function to prevent hydraulic lock within the tubing hanger plug 10. Such a trapped volume may otherwise prevent any movement of the seat 20 and associated valve sleeve 16.

(18) The housing 12 further comprises lower ports 36 which function to expose the floating piston 28 to downhole pressure, thus avoiding any potential for the floating piston 28 from being hydraulically locked within the housing 12.

(19) Although not shown, the housing 12 may comprise a sealing arrangement comprising one or more seals located on an outer surface thereof. The sealing arrangement may facilitate sealing of the tubing hanger plug 10 in a pipe, casing, tubular or the like.

(20) When the valve sleeve 16 is positioned in its fully open position, as shown in FIG. 2, the collet 24 of the valve sleeve 16 is latched into a section annular recess 38.

(21) Reference is now made to FIGS. 3A, 3B and 4, which illustrate a cross-sectional view of a second example of a downhole apparatus. FIGS. 3A, 3B and 4 share similarities with FIGS. 1 and 2, and as such like reference numerals have been used for like components, augmented by 100.

(22) As in the previous example, the apparatus, shown as tubing hanger plug 110, comprises a housing 112 having a number of fluid ports 114. A valve sleeve 116 is mounted within the housing 112, and in the initial configuration of FIG. 3A closes the fluid ports 114. O-ring seals 118 are provided between the valve sleeve 116 and the housing 112 to seal the fluid ports 114 closed.

(23) The valve sleeve 116 defines a seat 120, functional to be engaged by a ball 122 (shown in FIG. 4) which has been released from surface. In this example, the seat 120 is located at a midpoint along the valve sleeve 116, and is downhole of the upper axial end of the valve sleeve 116. According to the present disclosure, the seat 120 may be considered as having an intermediate location. The seat 120 includes bypass ports 123 which facilitate fluid bypassing the ball 122 (shown in FIG. 4) when engaged with the seat 120.

(24) In the example shown in FIGS. 3A, 3B and 4, the bypass 123 is located uphole of the seat 120, such that the ball 122 engages the seat downhole of the bypass 123, and therefore would not provide any restriction to flow through the bypass 123.

(25) As is most clearly shown in FIG. 3A and FIG. 4, the bypass 123 and the fluid ports 114 have a linear axis, which lies oblique relative to the axis of the hanger plug 110. The axes of the bypass 123 and the fluid ports 114 are parallel. As previously described, the fluid ports 114 being obliquely aligned with the axis of the hanger plug 110 may prevent erosion of a tubular, pipe, casing, or the like in which the hanger plug 110 is placed. Axial alignment of the bypass 123 and the fluid ports 114 may provide reduced fluid losses when there is fluid flow therethrough.

(26) In this example, in contrast to the example of FIGS. 1 and 2, the bypass 123 does permit fluid to bypass the ball 122 when engaged in the seat 120.

(27) An opposite, downhole, end of the valve sleeve 116 includes circumferentially extending teeth 124. In the configuration shown in FIG. 3A, the teeth are in close proximity with, and may abut, the housing 112. A ratchet component 138 is contained in a lower, downhole, section of the tubing hanger plug 110. The ratchet component 138 comprises a plurality of grooves, which may be engaged with the teeth 124 of the valve sleeve 116.

(28) As in the previous example, the tubing hanger 110 includes a barrier member in the form of a floating piston 128 located below the valve sleeve 116. The floating piston 128 is sealed with the housing 112 via O-ring seals 130, and includes a capped end 132, to provide isolation as in FIGS. 1 and 2. Spring 129 biases the floating piston in an upwards direction.

(29) As shown in FIG. 3B, shear pins 142 hold the sleeve 116 in the configuration shown in FIG. 3A. The shear pins 142 are in engagement with a corresponding indent 144 in the surface of the sleeve 116.

(30) As in FIGS. 1 and 2, the housing comprises lower ports 136, which function to expose the floating piston 128 to downhole pressure.

(31) In use, the ball 122 will act on the seat 120 to move the valve sleeve 116. Once the ball 122 seats in the valve seat 120, fluid pressure will act on the upper surface of the ball 122, causing shear pins 142 to shear (alternatively/additionally, impact of the ball 122 on the seat may provide sufficient force to shear the pins 142) which, as shown in FIG. 4, will cause the sleeve 116 to shift axially and open the ports 114, thus providing pressure equalization across the tubing hanger plug 110. When the sleeve 116 is in the fully open position, the axes of the sleeve 116 and the fluid ports 114 are aligned, as shown in FIG. 4.

(32) Axial shifting of the ball 122 and valve seat 120 causes the floating piston 128 to also move axially, permitting the trapped volume 134 to also move. Accordingly, the floating piston 128 may function to prevent hydraulic lock within the tubing hanger plug 110. The housing comprises a ridge 140 or axial shoulder which engages with a ridge 141 or shoulder on the floating piston to limit the movement of the floating piston 141, and therefore the sleeve 116, relative to the housing. The ridge 140 ensures that the spring 129 does not become fully compressed, and therefore may assist to preserve the longevity of the spring 129.

(33) Upon axial shifting, the teeth 124 of the sleeve 116 move into engagement with the ratchet component 138. The ratchet component 138 may function to retain the sleeve 116 in the position as shown in FIG. 4, and may permit the sleeve 116 to maintain a degree of partial movement, which may be related to the proximity of the spacing of the grooves in the ratchet component 138.

(34) In addition to retaining the apparatus in the fully open position as shown in FIG. 4, the ratchet component 138 may also permit the apparatus to be retained in a position where the fluid ports 114 and the bypass 123 are in partial alignment, i.e. where there is a degree of overlap between the fluid ports 114 and the bypass 123 and therefore a degree of fluid flow therethrough is possible, but the axes of the fluid ports 114 and bypass 123 are not aligned as shown in FIG. 4.

(35) The fluid ports 114 may have a substantially oval shape in radial cross-section. Such a cross-sectional shape may enable the ports to provide a gradual increase in a rate of fluid flow therethrough, as the fluid ports 114 and the bypass 123 move from being misaligned (e.g. when the sleeve 116 is in the closed position of FIG. 3A) to being aligned (e.g. when the sleeve 116 is in the open position of FIG. 4).

(36) Reference is now made to FIGS. 5 and 6, which show a third example of a downhole apparatus in the form of tubing hanger plug 210. FIGS. 5 and 6 share similarities with FIGS. 1 and 2, and as such like reference numerals have been used for like components, augmented by 200.

(37) In the example shown in FIGS. 5 and 6, the sleeve 216a, 216b, 216c, is separated into an upper sleeve 216a, an intermediate sleeve 216b and a lower sleeve 216c.

(38) The upper sleeve 216a comprises a lip 250. The lip 250 is in contact with an upper spring 252 which functions to bias the upper sleeve 216a towards a downward position. Upper sleeve 216a is held in an upwards position as a lower end 260 of the upper sleeve 216a is in abutment with an upper end 262 of the intermediate sleeve 216b. Upper sleeve 216a also comprises an upper sleeve port 254 which functions to facilitate movement of the upper sleeve 216a relative to the housing 212 by allowing fluid to escape from between the upper sleeve 216a and the housing 212, upon movement of the upper sleeve 216a (i.e., prevents hydraulic locking of sleeve 216a).

(39) The intermediate sleeve 216b comprises a seat 220, and is biased towards an upper position by spring 221, so as to close the fluid ports 214. Seal 255 prevents fluid flow between sleeve 216a, 216b, 216c and the housing 212 to the fluid ports 214. The inner surface of the intermediate sleeve 216b is in sliding engagement with the outer surface of the lower sleeve 216c. The spring 221 is held in an annulus 225 between the lower sleeve 216c and the housing 212. The lower sleeve 216c comprises a threaded portion 227 and is fixed relative to the housing 212 by threaded engagement. The lower sleeve 216c comprises a lower sleeve aperture 256 to allow fluid to enter and exit the annulus 225, preventing hydraulic locking.

(40) In use, ball 222 (FIG. 6) acts on the seat 220, and therefore the intermediate valve sleeve 216b to cause the intermediate valve sleeve 216b to shift axially relative to the housing 212 and open ports 214, thus providing pressure equalizations across the tubing hanger 210, as also shown in the previous examples.

(41) As the intermediate sleeve 216b shifts axially, upper spring 252 shifts the upper sleeve 216a downwardly until lip 250 of the upper sleeve 216a moves into abutment with the housing 212. As the intermediate sleeve 216b moves downwardly, the upper end 262 of the intermediate sleeve 216b moves past the seal 255. At the same time, the lower end 260 of the upper sleeve 216a, which is initially in abutment with the upper end 262 of the intermediate sleeve 216b, moves over the seal 255. As such, the upper sleeve 216a and intermediate sleeve 216b together ensure that the seal 255 is contained between the sleeve 216a, 216b and the housing 212, and thus protected from exposure to fluid flow/debris in the apparatus.

(42) The range of axial shifting of the intermediate sleeve 216b is greater than that of the upper sleeve 216a, and upon engagement of the ball 222 with the sleeve 220, the intermediate sleeve 216b moves, from a closed position, out of abutment with the upper sleeve 216a and towards an open position to expose fluid ports 214. Downwards axial shifting of the intermediate sleeve 216b is limited by engagement of the intermediate sleeve 216b with the lower sleeve 216c, as shown in FIG. 6.

(43) As in the previous examples, axial shifting of the sleeve 216a, 216b causes the floating piston 228 to move axially, permitting the trapped volume 234 to also move. Accordingly, the floating piston 228 may function to prevent hydraulic lock within the tubing hanger plug 210.

(44) FIG. 7 shows an application of a tubing hanger plug 310, which tubing hanger plug 310 may be provided in accordance with any of the examples provided above. FIG. 7 shares similarities with FIGS. 1 and 2, and as such like reference numerals have been used for like components, augmented by 300.

(45) As shown, the tubing hanger plug 310 is connected to a wellbore tool 370. The wellbore tool 370 comprises engagement members 372, which in this case are in the form of dogs. The tubing hanger plug 310 and wellbore tool 372 is positioned in, as shown in this example, a tubular component 374, which comprises an engagement profile 376. The tubular component 374 may form part of a completion, such as an upper completion, lower completion etc. In some examples the tubular component 374 may comprise a seal receptacle, such as a polished bore receptacle.

(46) In this example, the apparatus is able to be actuated so as to engage the engagement members 372 with the engagement profile 376. Actuation may be, for example, by movement of the sleeve (shown in FIGS. 1-6) of the tubing hanger plug 310.