Method And System For Remotely Signalling A Downhole Assembly Comprising One Or More Downhole Tool

Abstract

A method for remotely signalling a downhole assembly comprising one or more downhole tools includes operating a choke arrangement configured to control production fluid flow from a wellbore to produce a first pressure signature in the fluid flow, the first pressure signature defining a trigger signal for the one or more downhole tools of the downhole assembly. The first pressure signature comprises at least a first pressure signal and a second pressure signal in the production fluid flow in the downhole assembly. Operating the choke arrangement to produce a second pressure signature in the production fluid flow in the downhole assembly at a predetermined time period following the first pressure signature, the second pressure signature defining a command signal for initiating operation of a predetermined one or more of the downhole tools of the downhole assembly.

Claims

1. A method for remotely signalling a downhole assembly comprising one or more downhole tools, the method comprising: operating a choke arrangement configured to control production fluid flow from a wellbore to produce a first pressure signature in the fluid flow, the first pressure signature defining a trigger signal for the one or more downhole tools of the downhole assembly, wherein the first pressure signature comprises at least a first pressure signal and a second pressure signal in the production fluid flow in the downhole assembly; and operating the choke arrangement to produce a second pressure signature in the production fluid flow in the downhole assembly at a predetermined time period following the first pressure signature, the second pressure signature defining a command signal for initiating operation of a predetermined one or more of the downhole tools of the downhole assembly.

2. The method of claim 1, comprising the step of determining which of the one or more downhole tools is to receive the command signal before operating the choke arrangement to produce the first pressure signature.

3. The method of claim 2, wherein determining which of the one or more downhole tools is to receive the command signal comprises detecting and/or analysing a tracer element associated with one or more of the downhole tools and which is transportable with the production fluid flow.

4. The method of claim 1, wherein at least one of the first pressure signal and the second pressure signal comprises or takes the form of at least one of: a predetermined increase in fluid pressure of the production fluid flow; a predetermined decrease in fluid pressure of the production fluid flow; a static fluid pressure of the production fluid flow.

5. The method of claim 1, wherein the first pressure signature comprises n pressure signals, where n≥2.

6. The method of claim 1, wherein the or each downhole tool is operatively associated with a particular predetermined time period following the first pressure signature.

7. The method of claim 1, wherein the second pressure signature comprises a first pressure signal at a first predetermined time following the first pressure signature, the first pressure signal comprising at least one of: a predetermined increase in fluid pressure of the production fluid flow a predetermined decrease in fluid pressure of the production fluid flow; a static fluid pressure of the production fluid flow.

8. The method of claim 7, wherein the second pressure signature comprises a second pressure signal at a second predetermined time following the first pressure signature, the second pressure signal comprising at least one of: a predetermined increase in fluid pressure of the production fluid flow a predetermined decrease in fluid pressure of the production fluid flow; a static fluid pressure of the production fluid flow.

9. The method of claim 1, wherein the second pressure signature comprises n number of pressure signals, where n≥1.

10. The method of claim 1, comprising operating the choke arrangement to at least one of: increase the pressure of the production fluid flow; decrease the pressure of the production fluid flow; provide a static pressure of the production fluid flow.

11. The method of claim 1, comprising the step of detecting at least one of the first pressure signature and the second pressure signature using a downhole sensor arrangement forming part of, coupled to or operatively associated with the downhole assembly.

12. The method of claim 1, comprising operating the selected downhole tool or group of downhole tools in response to the detected command signal.

13. A downhole assembly comprising: one or more downhole tool for location in a wellbore; a sensor arrangement forming part of, coupled to or operatively associated with the one or more downhole tool, wherein the sensor arrangement is configured to detect a first pressure signature produced in the fluid flow in the downhole assembly by a choke arrangement, the first pressure signature defining a trigger signal for the downhole assembly, wherein the first pressure signature comprises at least a first pressure signal and a second pressure signal in the fluid flow in the downhole assembly, and wherein the sensor arrangement is configured to detect a second pressure signature produced in the fluid flow in the downhole assembly by the choke arrangement, the second pressure signature defining a command signal for initiating operation of a predetermined one or more downhole tool of the downhole assembly; and an actuation arrangement forming part of, coupled to or operatively associated with the one or more downhole tool, the actuation arrangement configured to initiate operation of the selected one or more downhole tool of the downhole assembly in response to the second pressure signature.

14. The assembly of claim 13, comprising a tracer element disposed on, coupled to, forming part of and/or operatively associated with the one or more downhole tools, the tracer element configured to be transported towards surface with the fluid flow from the wellbore, the tracer element indicating which of the one or more downhole tools is to receive the command signal.

15. The assembly of claim 14, wherein the tracer element is soluble and/or dispersable in contact with a selected fluid, for example water or hydrocarbons.

16. (canceled)

17. The assembly of claim 14, wherein the tracer element comprises or takes the form of a dye and/or a chemical tracer.

18. (canceled)

19. The assembly of claim 13, wherein the assembly comprises or take the form of a completion system.

20. The assembly of claim 13, wherein the one or more downhole tool comprises a downhole flow control device.

21. A system comprising: the downhole assembly according to claim 13; and a choke arrangement configured to control fluid flow from a wellbore, wherein the choke arrangement is configurable to produce the first pressure signature in the fluid flow, the first pressure signal defining the trigger signal for one or more downhole tool of the downhole assembly, and wherein the choke arrangement is configurable to produce the second pressure signal in the fluid flow at a predetermined time period following the first pressure signature, the second pressure signature defining the command signal for the selected one or more of the downhole tools.

22. The system of claim 21, wherein at least one of: the choke arrangement comprises or forms part of a surface choke arrangement; part of the choke arrangement is disposed downhole; and the choke arrangement comprises or takes the form of an adjustable choke.

23. (canceled)

24. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0095] These and other aspects will now be described, by way of example, with reference to the accompanying drawings, of which:

[0096] FIG. 1 shows a diagrammatic view of a system for remotely signalling a downhole assembly comprising one or more downhole tool;

[0097] FIG. 2 shows an enlarged view of first, downhole, part of the downhole assembly of the system shown in FIG. 1;

[0098] FIG. 3 shows an enlarged view of second, uphole, part of the downhole assembly of the system shown in FIG. 1; and

[0099] FIG. 4 shows a graph showing an example of the first pressure signature and the second pressure signature used to remotely signal one or more selected downhole tool of the downhole assembly shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE DRAWINGS

[0100] Referring first to FIG. 1 of the accompanying drawings, there is shown a system 10 for remotely signalling a downhole assembly 12 comprising a number of downhole tools 14A,14B,14C,14D,14E,14F.

[0101] As shown in FIG. 1, the illustrated system 10 includes a subsea wellbore 16 extending from a wellhead 18 disposed at the seabed S. A valve arrangement 20, which in the illustrated system 10 takes the form of a Christmas tree, is disposed on the wellhead 18 and communicates with surface via a marine riser 22.

[0102] While the illustrated system 10 takes the form of a subsea system 10, it will be understood that the system 10 may take any suitable form, whether subsea or onshore.

[0103] As also shown in FIG. 1, the valve arrangement 20 comprises a choke arrangement 24 configured to control production fluid flow from the wellbore 18. In the illustrated system 10, the choke arrangement 24 comprises an adjustable choke having a valve member movable relative to a valve seat so as to vary the area of a flow passage defined therebetween. The area of the flow passage is reduced by moving the valve member of the choke arrangement 24 towards the valve seat, the resultant reduction in the area of the flow passage causing an increase in pressure in the production fluid. The area of the flow passage is increased by moving the valve member of the choke arrangement 24 away from the valve seat, the resultant increase in the area of the flow passage causing a decrease in pressure in the production fluid.

[0104] As will be described further below, the choke arrangement 24 is operable to relay a trigger signal to the downhole assembly 12 and a command signal for initiating operation of a selected one or more downhole tool of the downhole assembly 12.

[0105] In the illustrated system 10 shown in FIG. 1, the downhole assembly 12 takes the form of a completion string, with a number of the downhole tools 14A,14B,14C disposed adjacent to, and operatively associated with, a first formation zone FZ1 and a number of the downhole tools 14D,14E,14F disposed adjacent to, and operatively associated with, a second formation zone FZ2.

[0106] The downhole assembly 12 further comprises barrier members 26, which in the illustrated system 10 comprise packers, for isolating portions of the annulus A between the assembly 12 and the wellbore 16 to facilitate zonal isolation of the formation zones FZ1,FZ2, and facilitate ingress of production fluid into the assembly 12 via the downhole tools 14A,14B,14C,14D,14E,14F.

[0107] Referring now also to FIGS. 2 and 3 of the accompanying drawings, which shows an enlarged view of part of the downhole assembly 12 shown in FIG. 1, it can be seen that the downhole tools 14A,14B,14C,14D,14E,14F take the form of flow control devices, each having a body 28A,28B,28C,28D,28E,28F having a lateral flow passage 30A,30B,30C,30D,30E,30F disposed therethrough for communicating production fluid into the downhole assembly 12 and a valve member 32A,32B,32C,32D,32E,32F configured to provide selective communication of the production fluid through the respective lateral flow passage 30A,30B,30C,30D,30E,30F.

[0108] In the illustrated downhole tools 14A,14B,14C,14D,14E,14F, the valve members 32A,32B,32C,32D,32E,32F take the form of sliding sleeves. However, it will be understood that the valve members may take any suitable form, such as a flapper.

[0109] The downhole tools 14A,14B,14C,14D,14E,14F are each configurable between a first, open, configuration in which production fluid ingress into the downhole assembly 12 is permitted and a second, closed, configuration in which production fluid ingress is prevented or at least restricted.

[0110] As shown in FIGS. 2 and 3, each of the downhole tools 14A,14B,14C,14D,14E,14F has an actuation arrangement, generally denoted 34A,34B,34C,34D,34E,34F. In the illustrated system 10, the actuation arrangements 34A,34B,34C,34D,34E,34F each take the form of a fluid powered actuation arrangement comprising an actuation piston 36A,36B,36C,36D,36D,36E,36F, each of the pistons 36A,36B,36C,36D,36D,36E,36F coupled to a respective valve member 32A,32B,32C,32D,32E,32F and operable to reconfigure their respective downhole tool 14A,14B,14C,14D,14E,14F from the first, open, configuration to the second, closed, configuration, and vice-versa.

[0111] As also shown in FIGS. 2 and 3, each of the downhole tools 14A,14B,14C,14D,14E,14F has a sensor arrangement, generally denoted 38A,38B,38C,38D,38E,38F. The sensor arrangements 38A,38B,38C,38D,38E,38F each comprise one or more pressure gauge 40A,40B,40C,40D,40E,40F operable to detect the pressure of the production fluid.

[0112] As shown in FIGS. 2 and 3, each of the downhole tools 14A,14B,14C,14D,14E,14F has a controller, generally denoted 42A,42B,42C,42D,42E,42F. The controllers 42A,42B,42C,42D,42E,42F are configured to receive one or more input signal from the sensor arrangements 38A,38B,38C,38D,38E,38F indicative of the pressure in the production fluid and output one or more command signal to the actuation arrangements 34A,34B,34C,34D,34E,34F to initiate operation of the valve members 32A,32B,34C,34D,34E,34F.

[0113] As described above, the choke arrangement 24 is operable to relay a trigger signal to the downhole assembly 12 in the form of a first pressure signature imparted into the production fluid flow and a command signal for initiating operation of a selected one or more downhole tool of the downhole assembly 12 in the form of a second pressure signature imparted into the production fluid flow.

[0114] Referring now also to FIG. 4 of the accompanying drawings, there is shown an example of the trigger signal and command signal used to operate downhole tools 14A,14B,14C of the downhole assembly 12.

[0115] As shown in FIG. 4, the trigger signal takes the form of a first pressure signature comprising three pressure pulses produced by adjusting the choke arrangement 24 as described above. In the illustrated system 10, the first pressure signature comprises a first pressure signal, a second pressure signal and a third pressure signal. The first pressure signal takes the form of a predetermined increase in fluid pressure of the production fluid flow maintained for a predetermined time period followed by a predetermined decrease in the fluid pressure of the production fluid flow. The second first pressure signal is identical to the first pressure signal, taking the form of a predetermined increase in fluid pressure of the production fluid flow maintained for a predetermined time period followed by a predetermined decrease in fluid pressure of the production fluid flow. The third pressure signal is identical to the first and second pressure signals, taking the form of a predetermined increase in fluid pressure of the production fluid flow maintained for a predetermined time period followed by a predetermined decrease in fluid pressure of the production fluid flow.

[0116] The sensor arrangements 38A,38B,38C,38D,38E,38F of all of the downhole tools 14A,14B,14C,14D,14E,14F of the downhole assembly 12 monitor—continuously or with sufficient sample rate to detect the trigger signal-the pressure of the production fluid flow, the controllers 42A,42B,42C,42D,42E,42F determining from the sensor data received from the sensor arrangements 38A,38B,38C,38D,38E,38F that the trigger signal has been produced.

[0117] The sensor arrangements 38A,38B,38C,38D,38E,38F of all of the downhole tools 14A,14B,14C,14D,14E,14F of the downhole assembly 12 continue to monitor—continuously or with sufficient sample rate—the pressure of the production fluid flow, controllers 42A,42B,42C,42D,42E,42F determining from the sensor data received from the sensor arrangements 38A,38B,38C,38D,38E,38F whether the command signal has been produced.

[0118] The command signal takes the form of a second pressure signature in the production fluid flow at a predetermined time period following the first pressure signature. As shown in FIG. 4, the second pressure signature comprises two pressure pulses at a time interval with corresponds to the downhole tools 14A,14C.

[0119] On detecting the second pressure signature, which will vary depending on which of the downhole tools 14A has been selected to operate, the controllers 42A,42B,42C,42D,42E,42F will act accordingly. In the illustrated system 10, the controllers 42A, 42C will send a command signal to their respective actuation arrangements 34A,34C to initiate operation of the downhole tools 14A,14C while the remaining controllers 34B,34D,34E,34F will either take no action or send a signal to their actuation arrangements 34B,34D34E34F to remain in their present state. The controllers 34B,34D,34E,34F may then return to a dormant state until a trigger signal is again detected.

[0120] In order to determine which of the downhole tools is to be operated, and as shown in FIG. 2, each of the downhole tools 14A,14B,14C,14D,14E,14F has a tracer element 44A,44B,44C,44D,44E,44F disposed thereon.

[0121] The tracer elements 44A,44B,44C,44D,44E,44F may take a number of different forms and in the illustrated system 10 the tracer elements 44A,44B,44C,44D,44E,44F take the form of a dye soluble in contact with water in the production fluid, and thus provide an indication of where water ingress is present.

[0122] By detecting and/or analysing the tracer elements 44A,44B,44C,44D,44E,44F at surface, the condition at a particular downhole tool 14A,14B,14C,14D,14E,14F may be determined, e.g. that a particular wellbore zone is subject to water ingress.

[0123] It will be recognised that the method, assembly and system described above are merely exemplary and that various modifications may be made without departing from the scope of the claimed invention as defined by the appended claims.

[0124] For example, while in the illustrated system 10, each of the downhole tools 14A,14B,14C,14D,14E,14F has a sensor arrangement 38A,38B,38C,38D,38E,38F, the downhole tools 14A,14B,14C operatively associated with the formation zone FZ1 may alternatively comprise a common sensor arrangement and the downhole tools 14D,14E,14F operatively associated with formation zone FZ2 may comprise a common sensor arrangement, such that all of the downhole tools operatively associated with a given formation zone may be operated together.

[0125] While in the illustrated system 10, each of the downhole tools 14A,14B,14C,14D,14E,14F has an actuation arrangement 34A,34B,34C,34D,34E,34F, the downhole tools 14A,14B,14C operatively associated with the formation zone FZ1 may alternatively comprise a common actuation arrangement and the downhole tools 14D,14E,14F operatively associated with formation zone FZ2 may comprise a common actuation arrangement, such that all of the downhole tools operatively associated with a given formation zone may be operated together.

[0126] While in the illustrated system 10, each of the downhole tools 14A,14B,14C,14D,14E,14F has a tracer element 44A,44B,44C,44D,44E,44F, the downhole tools 14A,14B,14C operatively associated with the formation zone FZ1 may alternatively comprise a common tracer element and the downhole tools 14D,14E,14F operatively associated with formation zone FZ2 may comprise a common tracer element.