Well Assembly Monitoring

Abstract

Herein disclosed is a well assembly comprising a sensor and a method of monitoring using the sensor. The well assembly may comprise a wellbore and the sensor, wherein the sensor is in a fixed location relative to the wellbore, and wherein the sensor is for monitoring the size and/or shape of the wellbore. The method may be a method of monitoring the size and/or shape of the wellbore. The method may comprise: providing the sensor in a fixed location relative to the wellbore, and monitoring the size and/or shape of the wellbore using the sensor. The well assembly may comprise a well foundation and the sensor, wherein the sensor is in a fixed location relative to the well foundation, and wherein the sensor is for monitoring the earth underneath the well foundation during installation of the well assembly. The method may be a method of monitoring the earth underneath the well foundation. The method may comprise providing the sensor in a fixed location relative to the well foundation, and monitoring the earth underneath the well foundation during installation of the well assembly.

Claims

1. A subsea well assembly, the subsea well assembly comprising: a wellbore; and a sensor, wherein the sensor is in a fixed location relative to the wellbore, and wherein the sensor is for monitoring the size and/or shape of the wellbore.

2. A subsea well assembly according to claim 1, wherein the sensor is for monitoring the size and/or shape of the wellbore during drilling of the wellbore.

3. A subsea well assembly according to claim 1 or 2, wherein the subsea well assembly comprises a well foundation, and wherein the sensor is fixed to the well foundation.

4. A subsea well assembly according to claim 3, wherein the well foundation is a suction anchor.

5. A subsea well assembly according to claim 3 or 4, wherein the sensor is for monitoring the size and/or shape of a borehole drilled through the foundation.

6. A subsea well assembly according to any preceding claim, wherein the sensor is for detecting structural defects that could affect the structural integrity of the subsea well assembly.

7. A method of monitoring the size and/or shape of a wellbore of a subsea well assembly, the method comprising: providing a sensor in a fixed location relative to the wellbore, and monitoring the size and/or shape of the wellbore using the sensor.

8. A method according to claim 7, wherein the method comprises monitoring the size and/or shape of the wellbore during drilling.

9. A method according to claim 7 or 8, wherein the subsea well assembly comprises a well foundation, and wherein the sensor is fixed to the well foundation.

10. A method according to claim 9, wherein the well foundation is a suction anchor.

11. A method according to claim 9 or 10, wherein the method comprises monitoring the size and/or shape of a borehole drilled through the foundation.

12. A method according to any of claims 7 to 11, wherein the method comprises detecting structural defects that could affect the structural integrity of the well assembly using the sensor.

13. A method according to any of claims 7 to 12, wherein the method comprises detecting a change in the size and/or shape of the wellbore, and taking remedial measures to avoid or minimise further change in the size and/or shape of the wellbore.

14. A subsea well assembly, the subsea well assembly comprising: a well foundation; and a sensor, wherein the sensor is in a fixed location relative to the well foundation, and wherein the sensor is for monitoring the subsea assembly during installation of the subsea well assembly and/or for monitoring earth underneath the well foundation during installation of the subsea well assembly.

15. A subsea well assembly according to claim 14, wherein the sensor is for monitoring the earth underneath the foundation during drilling.

16. A subsea well assembly according to claim 14 or 15, wherein the well foundation is a suction anchor.

17. A subsea well assembly according to claim 14, 15 or 16, wherein the sensor is for identifying a suitable location for the well foundation to be installed.

18. A subsea well assembly according to any of claims 14 to 17, wherein the sensor is for detecting structural defects that could affect the structural integrity of the well foundation.

19. A subsea well assembly according to any of claims 14 to 18, wherein the sensor is for monitoring cement during installation of the subsea assembly.

20. A method of monitoring a subsea well assembly and/or the earth underneath a well foundation of the subsea well assembly, the method comprising: providing a sensor in a fixed location relative to the well foundation, and monitoring the subsea well assembly during installation of the subsea well assembly and/or monitoring earth underneath the well foundation during installation of the subsea well assembly.

21. A method according to claim 20, wherein the method comprises monitoring the earth underneath the foundation during drilling using the sensor.

22. A method according to claim 20 or 21, wherein the well foundation is a suction anchor.

23. A method according to claim 20, 21 or 22, wherein the method comprises identifying a suitable location for the well foundation to be installed using the sensor.

24. A method according to any of claims 20 to 23, wherein the method comprises detecting structural defects that could affect the structural integrity of the well foundation using the sensor.

25. A method according to any of claims 20 to 24, wherein the method comprises monitoring cement during installation of the subsea assembly.

26. A method according to any of claims 7 to 13 and/or 20 to 25, wherein the subsea well assembly is a subsea well assembly according to any of claims 1 to 6 and/or 14 to 19.

Description

[0105] A preferred embodiment of the present invention will now be described by way of example only with reference to the accompanying drawing, in which:

[0106] FIG. 1 shows a well assembly comprising a sensor; and

[0107] FIGS. 2, 3, 4 and 5 show the installation of a well assembly comprising a sensor.

[0108] Considering first FIG. 1, the well assembly 1 comprises a sensor 2 that comprises a plurality of sensing devices 4. The sensing devices 4 are mounted to a well foundation 6 (which in this illustrated embodiment is a suction anchor). The sensing devices 4 are arranged to monitor the earth underneath the foundation 6, including the wellbore 7.

[0109] Whilst in this embodiment the sensing devices 4 are shown mounted at the bottom of the outer suction skirt 8 of the suction anchor 6 and at the bottom of the central tube 10 of the suction anchor 6, the sensing devices 4 may be located in any location that is fixed relative to the foundation 6 and/or the wellbore 7.

[0110] The sensing devices 4 are embedded in the seabed 12 and are arranged to monitor the earth underneath the well foundation 6, including the wellbore 7.

[0111] The sensing devices 4 are connected (in this case via wires though the connection may be by any means such as wireless connection) to a processor 14. The processor 14 may be on the foundation 6 as shown, or part of the sensor 2 or provided at a remote location (such as above the surface of the sea).

[0112] The sensor 2 may monitor the earth underneath the foundation 6 over time. The data sensed by the sensor 2 may be sent to the processor 14 where the data can be processed and used to determine if there are any defects in earth underneath the well foundation 6 that may affect the structural integrity of the well and foundation 6 etc. Data from the sensor 2 (processed or unprocessed) may be transferred to a remote location, such as a drilling unit.

[0113] The sensing devices 4 may provide information on the size and/or shape of the wellbore 7 over time. This may be used to detect defects forming such as washout 16. The sensing devices 4 may provide information during drilling of the wellbore 7. This may for example be by using a drill string 18 that drills the wellbore 7 through the well foundation 6.

[0114] The sensing devices 4 may be provided on the well foundation 6 prior to installation of the well foundation 6. Thus, the sensing devices 4 may be used to monitor the earth underneath the foundation 6 before it is fixed to the seabed 12 as illustrated for example with FIGS. 2, 3 and 4. Thus, the sensor 2 may be used to help identify a suitable location on the seabed 12 for the foundation 6 to be installed.

[0115] In the case that the foundation 6 is a suction anchor, it will be sucked into the seabed 12. The sensor 2 may be used to survey the earth underneath the surface of the seabed before the foundation is sucked into the seabed so as to allow a suitable location for the suction anchor 6 to be sucked into the seabed 12 to be identified. This may for example be a location that is free of significant hazards 20, such as boulders (which may impede installation of the foundation), shallow gas or gas hydrates etc (which may compromise later drilling operations).

[0116] As shown in FIG. 2, the sensor 2, and in particular sensing devices 4 attached to the bottom of the central tube 10, may be used to identify a hazard before the suction skirt 8 even reaches the seabed 12. The sensor 2 may be used to identify hazards that would be encountered by the central tube 10 as the foundation 6 is installed. If such a hazard 20 is identified, the foundation 6 may be installed in a different location such that the foundation does not encounter the hazard 20 as it is installed into the seabed as illustrated in FIG. 4.

[0117] As illustrated by FIG. 3, the assembly 1 may also comprise sensing devices 4 at the bottom of the suction anchor 6 itself. These sensing devices 4 may for example be attached to internal stiffeners within the suction anchor 6. These sensing devices 4 may be used to identify hazards 20 that the suction skirt 8 would encounter if the suction anchor 6 were fully sucked into the seabed. If such hazards 20 are identified, the foundation 6 may be installed in a different location such that the foundation does not encounter the hazard 20 as it is installed into the seabed as illustrated in FIG. 4.

[0118] As illustrated by FIG. 5, the sensor 2 may alternatively or additionally be used to monitor the earth underneath the foundation 6 after it has been fixed to the seabed 12. This may be during drilling, for example, when the risk of defects such as washout may be highest.

[0119] If defects are detected, or there is a change in the earth that suggests that a defect may occur, appropriate remedial measures may be taken. The remedial measures may prevent the defect developing further and/or causing any significant issue to the well components above the defect. The remedial measures may include casing, cementing and/or adjusting drilling parameters (such as drilling mud pumping rate) etc.

[0120] The sensor 2 may alternatively or additionally be used to monitor the well assembly 1 itself during installation. This may be during cementing, for example, when it would be beneficial to check that cement is provided to the desired locations.

[0121] Thus, the sensor 2 may be used to monitor the installation of the well assembly 1. This is so that it can be checked that installation has occurred as desired.