WO1997005759A2

WO1997005759A2 - Improved downhole apparatus

Info

Publication number: WO1997005759A2
Application number: PCT/GB1995/002046
Authority: WO
Inventors: Clive French
Original assignee: Clive French
Priority date: 1995-08-05
Filing date: 1995-08-31
Publication date: 1997-02-20
Also published as: GB9516114D0; AU3391995A; WO1997005759A3

Abstract

A downhole apparatus comprises: a tubular body (20); an actuator member (24) mounted on the body and moveable relative thereto by application of fluid pressure force, the actuator member being moveable from a first configuration to a second configuration; a valve (54) for controlling flow of fluid from the bore of the tubular body; and a linkage (60, 72) between the actuator member (24) and the valve (54) to permit actuation of the valve when the actuation member is in the second configuration. In use, the actuator member is preferably initially used in the first configuration and, in this configuration, the member is moveable to, for example, actuate another tool. However, if the actuator member is moved to the second configuration the movement of the member may be utilised to operate the valve, which may, for example, provide for fluid communication with one or more packers. Accordingly, the invention is useful in completions: after a string has been fully tested the actuating member may be moved to the second configuration to allow setting of a packer on the string.

Description

IMPROVED DOWNHOLE APPARATUS

This invention relates to apparatus for use in downhole operations. In particular, but not exclusively, the apparatus is intended for use in completion testing and in operations which take place immediately following completion testing.

In the oil and gas exploration and extraction industries, deep bores are drilled to gain access to hydrocarbon-bearing strata. The section of bore which intersects this strata or "production zone" is typically provided with a steel "liner", while the section of bore extending to the surface is lined with steel "casing" . Oil and gas is extracted from the production zone through production tubing extending through the casing from the upper end of the liner. The production tubing is formed of a string of threaded sections or "subs" which are fed downwards from the surface, additional subs being added at the surface until the string is of the desired length. As the string is assembled and fed into the bore its pressure integrity, or "completion", is tested at regular intervals. Such testing is also carried out on the complete string. The testing is accomplished by pressurising the internal bore of the string. Of course this requires that the string bore is sealed at its lower end. However, it is desirable that the string fills with well fluid as it is lowered into the bore. The applicant has previously developed a tool to accommodate these conflicting requirements, as described in GB-A-2 272 774. The tool includes an apertured sleeve mounted on a tubular body which forms part of the string. A port is provided in the body and is normally aligned with the port in the sleeve to permit well fluid to flow, from the annulus, into the string. However, on pressurising the string bore, by pumping fluid down the bore from the surface, the resulting pressure force acts on a piston defined by the sleeve to move the sleeve and seal the body port. The completion of the string may then be tested. On the pressure being bled off, a spring returns the sleeve to the initial position and opens the ports.

A string may carry a number of fluid pressure actuated tools or fittings, including packers for locating or sealing a production string within a casing. Typically, packers are mounted on the exterior of the string and are inflated or otherwise set, when the packer is in the desired location, to engage the casing wall. However, during completion testing any packers mounted on the string may be prematurely set by the application of the elevated completion testing pressures. Clearly this is not desirable, and may create difficulties as the string is moved downwardly and further into the bore.

It is among the objects of aspects of the present invention to obviate or mitigate one or more of these disadvantages.

According to the present invention there is provided downhole apparatus comprising: a tubular body; an actuator member mounted on the body and moveable relative thereto by application of a fluid pressure force, the actuator member being moveable from a first configuration to a second configuration; a valve for controlling flow of fluid from the bore of the tubular body; and a linkage between the actuator member and the valve to permit actuation of the valve when the actuation member is in the second configuration.

According to another aspect of the present invention there is provided a method of selectively actuating a downhole valve for providing fluid communication between the interior of a tubular body and an annulus, the method comprising: providing an actuator member mounted on a tubular body and moveable relative thereto by application of a fluid pressure force internally of the body, the actuator member being initially provided in a first configuration; and pressurising the interior of the body to move the actuating member to a second configuration, in the second position the member actuating the valve.

In use, the actuator member is preferably initially used in the first configuration and, in this configuration, the me ber is moveable to, for example, actuate another tool. However, if the actuator member is moved to the second configuration the movement of the member may be utilised to operate the valve, which may, for example, provide for fluid communication with one or more packers. Accordingly, the invention will be particularly useful in completions: after a string has been fully tested the actuating member may be moved to the second configuration to allow setting of a packer on the string. Preferably, the actuating member is also a valve member and defines a port which is normally in communication with a port in the body, to permit passage of fluid between the annulus and the interior of the body, and is moveable to close the body port. Most preferably, the actuating member is moveable in response to a differential pressure across the wall of the tubular body, or an elevated pressure within the body, in a similar manner to the tool disclosed in GB-A-2 272 774. The apparatus may thus be utilised, in the first configuration, for completion testing in a similar manner to that described in GB-A-2 272 774, and may then be utilised in the second configuration for, for example, selective setting of packers or to open full flow ports in the string.

The apparatus may include two or more valves for selectively controlling fluid communication to a plurality of respective tools and the like. Further, the actuating member may have further configurations to permit selective operation of such further valves; a single apparatus may thus be utilised to control setting of a packer and then a full flow sleeve.

Preferably, a ratchet or J-slot link is provided between the actuating member and the body and extends around at least a part of the circumference thereof, to control longitudinal movement of the actuating member relative to the body. The link thus includes a profiled surface and a follower, a first portion of the profile defining the first configuration and constraining the actuating member to movement within a first range, and a second portion of the profile defining the second configuration and permitting the actuating member to move beyond the first range of movement to actuate the valve. Conveniently, the follower may be moved along the profile, from the first portion to the second portion, by pressure cycling. Most preferably, the profile is configured such that a predetermined number of cycles will move the follower, from an initial position, to the second portion of the profile. The actuating member is preferably biassed to move in one longitudinal direction relative to the body; the actuating member may be biassed towards the first and second positions, or may be biassed away from these positions, requiring the application of a pressure force to move the member to the first and second positions.

Conveniently, the valve is provided in a centraliser located above or below the actuating member.

Preferably also, the valve is initially closed and is opened on movement of the actuating member to the second configuration. Most preferably, the valve includes a valve member which is moveable to allow fluid communication between a port in the body wall and a port in communication with a tool or the like mounted on the body.

The apparatus may be provided in combination with one or more packers or with a flow sleeve. The flow sleeve may be opened, following completion testing and setting of the packers, to allow fluid to flow between the lower end of the string and the annulus. The flow sleeve may comprise a tubular body with a port in the body wall, and an apertured sleeve mounted on the body, the body port initially being closed by the sleeve. A pressure port provides fluid communication between the valve and a piston face defined by the sleeve, and on opening the valve the fluid in the body bore may apply a pressure force to the sleeve and move the sleeve to a second position and open the body port. The sleeve may be retained in an initial position by releasable means, such as shear pins, and may be retained in the second position by a latch or ratchet. Biassing means, such as a spring, may also be provided to assist in moving the sleeve to the second position. The end of the flow sleeve body is initially closed, preferably by a removable plug. Thus, when it is desired to fully open the lower end of the string, the plug may be removed using, for example, wireline or coiled tubing provided with an appropriate fishing tool.

These and other aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: -

Fig. 1 is a somewhat schematic view of downhole apparatus in accordance with a preferred embodiment of the present invention, including a completion testing tool, two centralisers, a packer, and a full flow sleeve mounted on the end of a string;

Fig. 2 is an enlarged sectional view of the completion testing tool and a centraliser of Fig. 1;

Fig. 2A is a scrap view on arrow A of Fig. 2; Fig. 3 is a representation of the ratchet profile of the completion testing tool of Fig. 2;

Fig. 4 is an end view of a centraliser of Fig. 1;

Fig. 5 is a sectional view on line 5-5 of Fig. 4, illustrating a valve arrangement;

Fig. 6 is a sectional view on line 6-6 of Fig. 5, illustrating the valve arrangement;

Fig. 7 is a sectional view of the valve arrangement of Fig. 5, showing the valve arrangement in the open position, and

Fig. 8 is a somewhat enlarged sectional view of the full flow sleeve of Fig. 1.

Reference is first made to Fig. 1 of the drawings which illustrates downhole apparatus in accordance with a preferred embodiment of the present invention. The apparatus includes a completion testing tool 10, two centralisers 12,13, a packer 14, and a full flow sleeve 16. In this example, the apparatus 10 is mounted on the lower end of a tubular production string 18. As will be described, the completion test tool 10 is utilised as the string is extended into a bore lined with casing. At intervals the pressure integrity or "completion" of the string is tested using the tool 10. Once the string 18 has been made up to its full length and has been fully tested, the tool 10 is configured to allow setting of the packer 14. Following setting of the packer 14, the tool 10 is reconfigured to allow opening of the sleeve 16.

Reference is new made to Fig. 2 of the drawings which illustrates, in somewhat schematic fashion, the completion test tool 10 and the upper centraliser 12. The tool comprises a tubular body 20 defining a bore 22 which forms a continuation of the string bore. Mounted on the body 20 is an actuating member in the form of a sleeve 24. Both the body 20 and the sleeve 24 define flow ports 26,28 which are normally aligned to allow fluid to flow from the annulus between the sleeve 24 and the bore casing into the bore 22. Appropriate O-rings or S-seals are provided above and below the ports. Movement of the sleeve 24 relative to the body 22 is controlled by a ratchet 29 including a profile 30 (see Fig. 3) defined on an inner face of the body 20 and a follower 32 extending from the sleeve 24. Both Figs. 2 and 3 illustrate the follower 32 in an initial position engaging a first stop 33. This initial position, with the ports 24,26 aligned, is maintained by a spring 34 which biases the sleeve 24 downwardly relative to the body 20.

As the string 18 is run-in, the aligned ports 26,28 allow well fluid to flow into the string bore. However, when it is desired to test the completion of the string, mud pumps at the surface are started and pump fluid into the bore. The pumped flow of fluid cannot be accommodated by the aligned ports 26,28 such that the fluid pressure within the bore rises. This pressure acts upon an annular piston 36 defined on an inner face of the sleeve 24 and in communication with the bore 22 via piston ports 38. Thus, the sleeve 24 is pushed upwardly relative to the body 20. This relative movement results in the ports 26,28 becoming mis-aligned such that the body ports 26 are blanked off by the sleeve 24. The string bore is now sealed, and by monitoring the fluid pressure in the bore at the surface, the completion of the string may be confirmed. The position of the follower 32 on the profile 30 at this point, engaging the second stop 42, is shown in Fig. 3. Bleeding off pressure from the bore allows the spring 34 to move the sleeve downwardly once more though, due to the offset of the profile peak 40 from the stop 42 the follower 32 does not return to the stop 33 and the sleeve 24 is forced to rotate on the body 20 as it returns to its initial longitudinal position, with the follower 32 engaging a stop 43 aligned with the first stop 33. Of course, this requires that ports 26,28 are provided around the circumference of one or both of the body 20 and sleeve 24 to ensure that there are ports 26,28 in alignment after rotation of the sleeve 24 on the body 20.

The profile illustrated in Fig. 3 provides for the completion of the string to be tested on up to three separate occasions, though of course the profile could be configured to provide a smaller or greater number of testing opportunities. Typically, two completion tests are carried out, with a "spare" test position being available if necessary. In other cases additional "spare" test positions may be provided. However, on pressurising the string bore for a fourth time, the follower moves from the stop 46, aligned with the stop 33 and 43, to an opposing stop 48 which permits a greater degree of relative longitudinal movement between the sleeve 24 and the body 20 than the stop 42, allowing the sleeve 24 to move to a second longitudinal position. As will be described, this reconfiguring of the sleeve 24 on the body 20 allows actuation of a valve provided in the centraliser 12, to allow setting of the packer 14. On bleeding pressure off from the bore, the follower 32 travels to a further stop 50 which allows for a greater degree of downward movement of the sleeve 24 on the body 20 than provided by the stops 33,43,46. In this further configuration the sleeve 24 is used to actuate a valve provided in the centraliser 13 to allow opening of the sleeve 16, as will be described.

Reference is now also made to Fig. 4 of the drawings which is an end view of the centraliser 12 and shows a pressure port 52 which provides selective fluid communication, via a valve arrangement 54, as shown in Fig. 2 and as illustrated schematically in Figs. 5, 6 and 7 of the drawings, with a port 56 in communication with the string bore.

The valve arrangement 54 includes a cylindrical body 58 and a plunger or rod 60 extending from one end of the body 58 both located within a longitudinally extending valve chamber 62 defined by the centraliser 12. The body 58 carries two spaced seals 64,65 which, with the valve closed, isolate the string bore communicating port 56 from the pressure port 52. The free end of the rod extends frcm the open lower end of the chamber 62. The body and rod 58,60 are initially restrained against movement by a shear out circlip 68 mounted on the end of the rod 60 extending from the chamber 62 and abutting the centraliser lower face.

The pressure port 52 is connected to a fluid line 70 (Fig. 1) which leads to the packer 14. To set the packer 14, the valve 54 is opened allowing pressurised fluid from the bore to flow in through the port 56, through the valve arrangement 54, and then from the pressure port 52 into the packer 14. The valve 54 is opened by an actuation dog 72 on the upper end of the sleeve 24 (see Figs. 2 and 2A) pushing the rod 60 upwardly. However, the dog 72 only contacts the end of the rod 60 as the sleeve 24 is lifted relative to the body 20 and the follower 32 contacts the profile stop 48 which, as noted above, permits a greater degree of upward movement of the sleeve 24 than the earlier stops 42. Thus, the sleeve 24 only moves sufficiently to contact the rod 60 on its fourth pressure cycle, and typically after two completion testing operations and a further pressure cycle.

On the packer being correctly set, a hydraulic piston or other moving part within the packer 14 reaches the end of its travel and contacts a transmitter switch, causing a transmitter on the packer 14 to transmit a signal, typically a "ping", which may be detected at the surface. This informs the operator that the packer has been set. Where a number of packers are provided, each may include a transmitter which transmits a different frequency signal, allowing the operator to determine which packers have been set.

The lower centraliser 13 is similar to the upper centraliser 12 described above and may be configured to allow fluid from the string bore to flow into and actuate the full flow sleeve 16, as will now be described with reference to Fig. 8 of the drawings. The sleeve 16 has a body 76 forming the lower end of the string and defining a through bore 78, though initially the lower end of the bore 78 is sealed by a removable plug 80. The body wall defines a number of ports 84 which are initially blanked off by a sleeve 86, movably mounted over the body 76. The sleeve defines a number of ports 88 which, as will be described, may be aligned with the body ports 84 to allow flow of fluid between the string bore and the annulus. Appropriate O-rings or S-seals are provided above and below the ports 88.

The sleeve 86 is biased towards the position in which the ports 84,88 are aligned by a spring 95 but is initially held on the body, such that the ports mis-aligned, by shear pins 90. To move the sleeve 86 and align the ports 84,88, pressure is applied through pressure port 82, which communicates with the pressure port 52 of the centraliser 13. The pressure force exerted by the fluid acts on an annular piston 94 defining the lower wall of a spring chamber in the sleeve 86, to shear the pins 90, and allowing the spring 95 to push the sleeve 86 downwardly relative to the body 76. A latch arrangement 96 is provided between the body 76 and the sleeve 86 to prevent retraction of the sleeve 86 once the ports 84,88 have been aligned, and a guide pin 97 ensures proper alignment of the sleeve 86 on the body 76.

The valve in the centraliser 13, which allows fluid to flow from the string bore into the port 92, is actuated by a dog 98 on the lower end of the sleeve 24 (see Fig. l) . The dog 98 contacts the centraliser valve rod 60 only when the follower 32 moves towards the stop 50 of the profile 30 (see Fig. 3) , which permits a greater degree of downward movement of the sleeve 24 than the earlier stops 33,43,46.

This additional movement of the sleeve 24 closes the ports 26,28 and the piston ports 38, to allow the string bore to be pressurised. Also, the position of the next stop 51 on the profile 30 prevents subsequent upward movement of the sleeve 24 to the extent necessary to re¬ align the bores 26,28, and thus effectively latches the sleeve 24 in the closed position.

The plug 80 may remain in place until it is necessary to provide unrestricted passage through the string bore. The plug 80 is supported against downward movement by a bore restriction 100, to prevent the plug 80 being pushed from the body 76 by completion testing pressures within the bore, and shear pins 101 prevent upward movement. The plug defines a test port 104. To remove the plug 80 from the bore 78 it is simply necessary to lower a suitable fishing tool on coiled tubing to engage the plug fishing neck 102 and then pull upwardly to shear the pins 101. The plug 80 may thus be withdrawn from the bore 78.

It will be noted from the above described embodiment that the apparatus provides a convenient arrangement for sequentially testing the completion of a string, setting a packer and then actuating a full flow sleeve, merely by cycling the pressure of fluid in the string bore. It will be clear to those of skill in the art that the apparatus may be utilised in combination with other tools and may also be used to actuate three or more tools in addition to the completion test tool 10.

Claims

1. Downhole apparatus comprising: a tubular body; an actuator member mounted on the body and moveable relative thereto by application of a fluid pressure force, the actuator member being moveable from a first configuration to a second configuration; a valve for controlling flow of fluid from the bore of the tubular body; and a linkage between the actuator member and the valve to permit actuation of the valve when the actuation member is in the second configuration.

2. The apparatus of claim 1, wherein the actuator member is moveable relative to the body while in the first configuration and is moveable relative to the body while in the second configuration.

3. The apparatus of claim 1 or 2, wherein the actuating member is also a valve member and defines a port which is normally in communication with a port in the body, to permit passage of fluid between the annulus and the interior of the body, and is moveable to close the body port.

4. The apparatus of claim 1, 2 or 3, wherein the actuating member is moveable in response to a differential pressure across the wail of the tubular body.

5. The apparatus of any of the preceding claims wherein the apparatus includes two or more valves for controlling fluid communication to a plurality of respective tools and the like.

6. The apparatus of any of the preceding claims wherein a ratchet or J-slot link is provided between the actuating member and the body and extends around at least a part of the circumference thereof, to control longitudinal and rotational movement of the actuating member relative to the body.

7. The apparatus of claim 6, wherein the link includes a profiled surface and a follower, a first portion of the profile defining the first configuration and constraining the actuating member to movement within a first range, and a second portion of the profile defining the second configuration and permitting the actuating member to move beyond the first range to actuate the valve.

8. The apparatus of claim 7, wherein the follower is moveable along the profile by pressure cycling.

9. The apparatus of claim 8, wherein the profile is configured such that a predetermined number of cycles will move the follower, from an initial position, to the second portion of the profile.

10. The apparatus of any of the preceding claims wherein the actuating member is biased in one longitudinal direction relative to the body and is moveable in the other direction by application of a fluid pressure force.

11. The apparatus of any of the preceding claims wherein the valve is provided in a centraliser located above or below the actuating member.

12. The apparatus of any of the preceding claims wherein the valve is initially closed and is opened on movement of the actuating member to the second configuration.

13. The apparatus of any of the preceding claims, wherein the valve includes a valve member which is moveable to allow fluid communication between a port in the body wall and a port in communication with a tool or the like mounted on the body.

14. The apparatus of any of the preceding claims in combination with one or more packers or with a flow sleeve.

15. The apparatus of any of claims 1 to 13 in combination with a flow sleeve, wherein the flow sleeve comprises a tubular body with a port in the body wall, and an apertured sleeve mounted on the body, the body port initially being closed by the sleeve, a pressure port providing fluid communication between the valve and a piston face defined by the sleeve, and on opening the valve the fluid in the body bore applying a pressure force to the sleeve and moving the sleeve to a second position and open the body port.

16. The combination of claim 15, wherein the sleeve is retained in an initial position by releasable means and is retained in the second position by a latch or ratchet.

17. The combination of claim 15 or 16, wherein biassing means is provided to assist in moving the sleeve to the second position.

18. The combination of claim 15, 16 or 17, wherein the end of the flow sleeve body is initially closed by a removable plug.

19. A method of selectively actuating a downhole valve for providing fluid communication between the interior of a tubular body and an annulus, the method comprising: providing an actuator member mounted on a tubular body and moveable relative thereto by application of a fluid pressure force internally of the body, the actuator member being initially provided in a first configuration; and pressurising the interior of the body to move the actuating member to a second configuration, in the second configuration the member actuating the valve.