SUBSEA COMMUNICATIONS MULTIPLEXER
A system for communicating between a surface facility and a subsea production control system includes a communications device proximate the water surface. The water surface communications device has at least one communication interface. A communications device is functionally associated with a wellhead or subsea structure proximate the water bottom. The water bottom communications device has at least one communication interface. A communication channel extends between the surface communication device and the water bottom communication device. A multiplexer is functionally coupled to the communication interface on each of the surface and water bottom communication devices. At least two remote devices are functionally coupled to the water bottom multiplexer. The remote devices comprise at least one of a sensor and a control. At least two corresponding devices are coupled to the surface multiplexer. The corresponding devices include at least one of a signal acquisition device and a control signal generating device.
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BACKGROUND OF THE INVENTION1. Field of the Invention
The invention relates generally to the field of devices used to communicate signals between a wellbore or seafloor-based device having production control equipment at the bottom of a body of water and production facilities located at the water surface. More particularly, the invention relates to signal multiplexing devices that enable signals to and from a plurality of wellbore or seafloor-based devices to communicate to the production facilities using existing water bottom to water surface communication channels.
2. Background Art
U.S. Patent Application Publication No. 2004/0262008 A1 filed by Deans et al. and incorporated herein by reference describes a system for communicating signals from a production facility located at the surface of a body of water, such as a floating production, storage and offloading facility (“FPSO”) or a floating production platform, for example, to and from a wellbore drilled through subsurface formations below the bottom of the body of water or to and from sensors and equipment located on the seafloor. The wellbore includes various sensors and control devices connected to a communication linking device disposed in a “wellhead” system disposed near the water bottom. The seafloor equipment can include various sensors mounted on seabed production equipment disposed on the water bottom.
In some instances, it may be desirable to add sensors and/or control devices to an existing wellbore or seafloor equipment, or to be able to couple sensors and/or control devices from additional wellbores or seafloor equipment to an existing communication link. Such need could be addressed by adding an additional communication channel. Such need could also be addressed by providing additional interfacing devices between such additional sensors/controls and an existing communication channel. The latter option has been made less desirable by adoption of certain industry standard communication configuration and protocol. The configuration and protocol are described in, Intelligent Well Interface Standardisation (“IWIS”) Panel, published by OTM Consulting Ltd., 44 Quarry Street, Guildford, Surrey GU1 3XQ, United Kingdom. The adopted standards limit the number of device interfaces that may be used in association with a communication channel. Other communications standards include the subsea instrumentation interface standardization (“SIIS”) interface standard, also published by OTM Consulting Ltd. and the subsea fibre optic montoring group (“SeaFOM”) standard for fiber optic subsea equipment, also published by OTM Consulting Ltd.
It is desirable to provide additional control device and/or sensor communication capacity to an existing water bottom to water surface communication channel without increasing the number of device interfaces.
SUMMARY OF THE INVENTIONA system for communicating between a surface facility and a subsea production control system includes a communications device proximate the water surface. The water surface communications device has at least one communication interface. A communications device is functionally associated with a wellhead or other production control structure such as a production manifold proximate the water bottom. The water bottom communications device has at least one communication interface. A communication channel extends between the surface communication device and the water bottom communication device. A multiplexer is functionally coupled to the communication interface on each of the surface and water bottom communication devices. At least two remote devices are functionally coupled to the water bottom multiplexer. The remote devices are at least one of a sensor and a control. At least two corresponding devices are coupled to the surface multiplexer. The two corresponding devices include at least one of a signal acquisition device and a control signal generating device.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
Other, various types of sensors and/or control devices 30 may be placed at or near the water bottom (sea bed), either in the subsea wellhead equipment 24, at or within flow conduits arranged on the seabed, on a hydrocarbon-gathering manifold, a water-injection manifold, or elsewhere above or on the water bottom but below the sea surface. The sensors and/or control devices 30 (collectively “water bottom devices”) can include, as non-limiting examples, a corrosion monitor, a sand monitor, a subsea flow meter, a pump, a flow line measurement sensor, a seabed acoustic sensor, a deposition sensor, a seabed seismic sensor. The various subsea sensors and/or control devices 30 are also coupled to the subsea production control system 26. Such sensors and/or control devices can be coupled to the control system 26 using fiber optic monitoring and control lines. For purposes of defining the sensors can be interrogated or what control devices can be operated, the term “remote device” is used herein to mean any device that generates a signal either as indication of a change in status (such as a control device being switched on or off) or in response to detection of a physical parameter (a sensor), or any device that changes its operation in response to a control signal (i.e., a control device such as a valve being opened or closed or a pump being switched on or off).
The subsea production control system 26 provides control signals to the various subsea sensors and/or control devices and to the various downhole sensors and/or control devices. The subsea production control system 26 may also provide control signals to wellhead equipment 24 components, such as valves. The subsea production control system 26 may include a local processor (not shown) that can generate such control signals in response to parameters detected by one or more sensors (e.g., 14, 16, 18 and 30 in
In the present description a “subsea” device (such as a subsea sensor or a subsea control device) refers to a device located generally at or above the water bottom but below the sea surface. A “downhole” device refers to a device placed in the well 10 or in another well drilled through the subsurface. More generally, a “device” (such as a sensor or a control device) associated with a subsea well refers to either a subsea device or a downhole device.
In one example implementation, the subsea production control system 26 is able to receive measurement signals from one or more of the sensors associated with a subsea well for communication to a surface facility 32 over a communications link 34. The communications link 34 can be provided through a flexible power/signal and/or produced fluid conduit called an “umbilical” 35 extending from the subsea wellhead equipment 24 to the surface facility 32. Usually, hydraulic, electrical power and other control lines are also provided through the umbilical 35. The subsea production control system 26, as previously stated, may also accept control signals from equipment (
The communications link 34 can be implemented using electrical cable, fiber optic lines, or, other types of communications links such as acoustic telemetry through the water. The subsea production control system 26 typically has a communications interface that uses a proprietary communications protocol for communicating signals between the subsea production control system 26 and the equipment (
In the example arrangement shown in
One example of a multiplexer module 28 used with a subsea production control system 26 is shown schematically in
In a different example shown in
In the present example, multiplexed signals, originating from the multiplexer (42 in
A system according to the invention also relates to the control, supply and monitoring of the electrical power to each device interface card (44 in
The surface multiplexer 52 packages the communications message with a unique device identifier or address and sends it to the surface acquisition system 48 for communication to the subsea production control system (26 in FIG. I) over the communication channel 34. The message is then delivered to the multiplexer module (28 in
A multiplexing system according to the various aspects of the invention may provide the capability of adding multiple additional subsea and/or downhole devices to an existing subsea production monitoring and control system without the need to modify such system and without the need to add additional communication channels between the wellhead equipment and the surface facility.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims
1. A system for communicating between a surface facility and a subsea production control system, comprising:
- a communications device proximate the water surface, the water surface communications device having at least one communication interface;
- a communications device functionally associated with the subsea production control system proximate the water bottom, the water bottom communications device having at least one communication interface;
- a communication channel extending between the surface communication device and the water bottom communication device;
- a multiplexer functionally coupled to the communication interface of each of the water bottom and water surface communication devices;
- at least two remote devices functionally coupled to the water bottom multiplexer, the devices comprising at least one of a sensor and a control; and
- at least two corresponding devices coupled to the surface multiplexer, the at least two corresponding devices comprising at least one of a signal acquisition device and a control signal generating device.
2. The system of claim 1 wherein at least one remote device is disposed proximate the water bottom.
3. The system of claim 1 wherein at least one remote device is disposed within a wellbore.
4. The system of claim 1 wherein at least one remote device comprises a pressure sensor.
5. The system of claim 1 wherein at least one remote device comprises a temperature sensor.
6. The system of claim 1 wherein at least one remote device comprises a pump.
7. The system of claim 1 wherein at least one remote device comprises a valve.
8. The system of claim 1 wherein the communication channel comprises electrical cable.
9. The system of claim 1 wherein the communication channel comprises a fiber optic communication line.
10. The system of claim 1 wherein the subsea production control system comprises at least one of a, fibre optic monitoring line, a sand detection sensor, a flowrate sensor, a corrosion sensor, a deposition sensor, a micro-seismic sensor, a strain sensor, a vibration sensor, and a position sensor.
11. The system of claim 1 wherein the water bottom multiplexer is disposed within a housing with a subsea production control system.
12. The system of claim 1 wherein the water bottom multiplexer includes a communication interface coupled between the multiplexer and at least one of the remote devices.
13. The system of claim 1 wherein the water bottom communication device comprises only one communication interface.
14. The system of claim 1 wherein the water bottom communication device and the water surface communication device are configured to operate with a proprietary communication protocol.
15. The system of claim 1 further comprising at least one of a data acquisition system and a device control system in signal communication with the water surface communication device, at least one of a data acquisition system and a device control system configured to selectively switch on and switch off operation of at least one of the remote devices by generating a control signal therefore.
16. The system of claim 1 wherein the subsea multiplexer is configured to control the operating power of each individual multiplexed device or sensor.
17. The system of claim 1 further comprising a stand-alone communications device mounted proximate the seafloor and external to the subsea production control system.
Type: Application
Filed: Mar 6, 2007
Publication Date: Sep 11, 2008
Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION (Sugar Land, TX)
Inventor: Gregor Deans (Paris)
Application Number: 11/682,694
International Classification: E21B 7/00 (20060101);