The present invention relates to a system for remotely controlling a running tool to install equipment in a subsea well through a subsea structure. The present invention also relates to a method of remotely controlling a running tool to install equipment in a subsea well through a subsea structure.
An important activity in the offshore petroleum industry is operating a running tool for setting equipment on a wellhead or on a wellhead module such as a valve tree (also known as Christmas tree) of a subsea well. One example of a running tool operation is setting a tubing hanger with the help of a tubing hanger running tool being controlled from a floating vessel. The tubing hanger is a device that is typically attached to the topmost tubing joint in a wellhead and that supports a tubing conduit within a wellbore under the wellhead. Once set, the tubing hanger is part of a sealing system which ensures that the tubing conduit and annulus are hydraulically isolated.
When this type of operation is carried out, there is a need for the running tool to receive power, often in the form of hydraulic and/or electric power, and network connections for exchanging data and control signals with a control system on the floating vessel. A well-known approach for supplying power to and communication with a running tool is to provide an umbilical between the floating vessel and the running tool. Electric and/or hydraulic power units are provided on the floating vessel, and these power units transmit power to the running tool via the umbilical. Also, the umbilical allows an operator to control the running tool, e.g. through an optical fiber cable. This approach is known to have several drawbacks. Firstly, the offshore operations related to establishing the umbilical require drilling rig workers to enter the “red zone” of the drilling rig in order to perform tasks such as clamping the umbilical to the drill pip. The entrance into the red zone of a drilling rig entails safety risks. Also, these tasks take time to perform, which is expensive an offshore context. Secondly, the umbilical is challenging to use and operate. The outside of an umbilical typically ranges from 25 to 100 mm, and it is not unusual for the umbilical to include 10 to 20 separate hydraulic lines, in addition to electric cables for transmitting electric power and further network cables for communication. The umbilical line can require large amounts of space on the deck of the floating vessel which could be utilized for other equipment. Thirdly, the umbilical can be damaged due to large mechanical stresses caused by the floating vessel and the marine riser moving because of environmental loads, such as waves and sea currents. Fourthly, the use of an umbilical also poses risks of damage to the production tubing or downhole equipment.
It can be challenging to provide an alternative to controlling a running tool using the well-known umbilical cable approach.
A known alternative approach is disclosed in WO 2016/182449 A1, which generally aims to replace the umbilical by providing alternative means for achieving all the same functions as those achieved by the umbilical. For providing power to the running tool, this document discloses providing the hydraulic and/or electric power units in a localized manner and proximity to the running tool. Thus, the power unit(s) are also run-in hole and pulled out of hole together with the running tool. For providing communication between the floating vessel and the running tool, this document suggests using a “penetrator” approach, which includes providing a blow-out preventer with a transmitter placed between the inside and the outside of the blow-out preventer. Such a feedthrough can be provided through a choke, kill or booster port of a blow-out preventer, and is typically referred as a “penetrator”. The penetrator approach has several drawbacks. Firstly, as described in page 6, third paragraph, this approach requires that the penetrator can withstand a high differential pressure between the high pressure inside the blow-out preventer and the hydrostatic water pressure at which the blow-out preventer is subjected on its outside. Secondly, the penetrator cannot be moved once installed on the blow-out preventer. Thirdly, a penetrator is limited to providing a communication channel through the structure of the blow-out preventer. Thus, a running tool will only be contactable after having already passed the flex joint connecting the marine riser and the blow-out preventer, which may be restrictive in several operations. Fourthly, providing a penetrator on a blow-out preventer can be a safety risk.
Another known approach generally relates to using wired drill pipe for providing communication between the floating vessel and the tubing hanger running tool. Wired drill pipe may comprise modified tubulars that include data cables along the internal diameter and inductive coils in the connection between tubulars for achieving inter-tubular communication. In practice, is has been observed that this approach is not as advantageous as expected, because it requires a lot of space on the deck of the floating vessel. Also, this approach requires personal to enter the red zone in order to perform operations.
The invention will now be disclosed and has for its object to remedy or to reduce at least one of the drawbacks of the known prior art, or at least provide a useful alternative to the known prior art. The object is achieved through features, which are specified in the description below and in the claims that follow. The invention is defined by the independent patent claims, and the dependent claims define advantageous embodiments of the invention.
According to a first aspect of the invention, there is provided a system for remotely controlling a running tool to install equipment in a subsea well through a subsea structure. The system comprises:
The first and the second wireless communication interfaces are adapted for subsea communication with each other through the subsea structure when the control device is provided internally to the subsea structure and the communication module is provided externally to the subsea structure. Also, the memory of the control device is configured with:
Moreover, the control device is configured to carry out the following steps:
It has been realized that controlling a running tool within a subsea structure, which may include for example a marine riser or a blow-out preventer, can be accomplished by providing: a control device configured with the programs for controlling the running tool to install the equipment; and wirelessly communicating with the control device through a subsea communication channel crossing the subsea structure, the communication being based on state identifiers for representing the internal state of the running tool. This solution counters the approach of continuously providing live feedback from the running tool to topsides, which requires a network capable of transmitting very high quantities of data to the floating vessel. Also, this solution is advantageous in that it overcomes the drawbacks previously observed. For example, this solution does not require personal on the floating vessel to enter the “red zone”.
Each of the first and second wireless communication interfaces may comprise a magnetic induction antenna. Although the use of a magnetic induction antenna may achieve a lower data transmission rate than when using a network cable extending to the control device (via an umbilical) from the floating vessel, the use of state identifiers configured in the memory of the control device allows making use of the lower data transmission rate in an effective manner.
In one embodiment, the control device may be connected to the first wireless communication interface via a network cable.
The communication module may be installable on an external surface of the subsea structure.
The system may comprise a remotely operated vehicle adapted to carry the communication module underwater.
The system may comprise a remote-control device adapted to communicate with the control device via the communication module, the remote-control device comprising a processing unit and a memory configured with:
The remote-control device may be adapted to communicate wirelessly, underwater with the communication module.
The system may comprise at least one energy storage device for providing power to the running tool.
According to a second aspect of the invention, there is provided a method of remotely controlling a running tool to install equipment in a subsea well through a subsea structure, the method comprising the steps of:
The method further comprises the steps of:
The step of positioning the communication module of the system externally to the subsea structure may comprise a step of installing the communication module externally to the subsea structure.
In one embodiment, the step of providing a system as described in the first aspect of the invention comprises providing a system which comprises a remotely operated vehicle adapted to carry the communication module underwater. In that embodiment, the step of placing the communication module of the system externally to the subsea structure comprises the step of operating the remotely operated vehicle to place the communication module of the system externally to the subsea structure.
The step of arranging the equipment, the running tool and the control device of the system into an assembly may comprise the step of performing at least one test for confirming that the control device is adapted to control to the running tool.
The subsea structure may comprise a marine riser and/or a blow-out preventer. The equipment may be a tubing hanger and the running tool may be a tubing hanger running tool.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Turning now to
It can be observed that there is a subsea structure 400 provided between the semi-submersible platform and the well head 501. In this operation example, the subsea structure 400 includes a marine riser 401, which is partly illustrated under the semi-submersible platform. The remaining portion of the marine riser 401 has been hidden for the purpose of improving the visualization of the devices and components shown in
An assembly is being lowered from the semi-submersible platform, and this assembly includes the tubing hanger 300, which is the equipment that will be installed on the well head 501, a running tool 200 for setting the tubing hanger 300 on the well head 501, and a control device 110 for controlling the running tool 200. This assembly is being lowered within the marine riser 401, which, as already explained, is partly shown in
In some system 100 embodiments, there may also be included at least one energy storage device for providing power to the running tool 200. Such an energy storage device may include an electric and/or a hydraulic power unit. When such an energy storage device is included in the system 100, it is part of the assembly being lowered from the floating vessel, e.g. a semi-submersible platform. Also, the at least one energy storage device may be implemented as part of the control device 110.
The control device 110, which is being lowered in the assembly, is part of the system 100 embodiment shown in
Each of the control device 110 and the communication module 120 includes a wireless communication interface embodiment, and this allows implementing a wireless communication channel between the control device 110 when the latter is provided within the subsea structure 400 (e.g. within the marine riser 401 in the situation shown in
The two wireless communication interfaces are adapted for subsea communication with each other through the subsea structure 400 when the control device 110 is provided internally to the subsea structure 400 and the communication module 120 is provided externally to the subsea structure 400. In a preferred embodiment, each of the wireless communication interfaces 111,122 includes a magnetic induction antenna for communicating subsea and through at least one part of the subsea structure 400. In some embodiments, other wireless communication technologies can be used separately or in combination with the magnetic induction antenna.
In
The memory of the control device 110 has been configured with at least one state identifier for representing an internal state of the running tool 200. For example, a state identifier may relate to a condition that is observable in the equipment 300, such as stating that a part of the equipment is at a certain position (e.g. “flange 1 is oriented”). The memory of the control device 110 is also configured with at least one program, each program being associated with at least one operation for controlling the running tool 200. With these memory configurations, the control device 110 can be commanded to carry out programs and to use state identifiers to report on the state of the running tool 200.
The system 100 embodiment shown in
It is also observable in
In
In one method embodiment, a running tool 200 can be remotely controlled to install equipment 300 in a subsea well through a subsea structure 400. Such a method embodiment can include three stages: a pre-operation stage, which includes steps for achieving an assembly that can be run into a subsea structure 400; a positioning stage, which includes steps for achieving a communication channel between a control device 110 positioned within the subsea structure 400 and a communication module 120,121 positioned externally to the subsea structure 400; and an execution stage, which includes steps for commanding the control device 110 to operate the running tool 200, possibly for controlling the running tool 200 to install the equipment 300.
In the pre-operation stage, the method includes the steps of providing the equipment 300 to be set in the subsea well, the running tool 200 to install the equipment, and a system 100 embodiment, for example, as described above with reference to
The skilled person will know obvious embodiments for the pre-operation stage. For example, the skilled person may prefer to perform some or all the stage steps onshore and prior to departure to the semi-submersible platform. This can be advantageous in that it minimizes the complexity and duration of the offshore work. Also, the pre-operation stage may include the step of function testing the arranged assembly. For this purpose, a communication module 120,121 embodiment may be provided and used for establishing a communication channel with the control device 110 without being subsea nor having the subsea structure 400 standing between the communication module 120,121 and the control device 110.
In the positioning stage, the method includes the step of positioning the communication module 120,121 externally to the subsea structure 400. As described above with reference to
The positioning stage also includes the step of positioning the assembly (which is arranged during the pre-operation stage) internally to the subsea structure 400 so that the control device 110 and the communication module 120,121 may communicate subsea with each other through the subsea structure 400. This step may include moving the assembly within the subsea structure 400 until it establishes a communication channel with the communication module 120,121. In another embodiment, the step of positioning the assembly may include moving the assembly to a depth at which the establishment of the communication channel is expected to occur. This embodiment is possible given that the hoisting means provided on a floating vessel typically has a depth control that is sufficiently precise for establishing the communication channel.
Moreover, in a system 100 embodiment including a remotely operated vehicle 140 carrying the communication module 121, it is possible to make combinations of method steps involving movements of the assembly within the subsea structure 400 with matching movements of the remotely operated vehicle 140 (and, consequently, of the communication module 121) on the outside of the subsea structure 400. Thus, it is possible to have the remotely operated vehicle 140 move (or “fly”) parallelly to the movement of the assembly, while keeping the communication channel between the control device 110 and the communication module 121 in effect during the assembly movement.
In the execution stage, the method includes the steps of:
When the system includes a remote-control device 130 (for example, as shown in
The skilled person will know other stages that may be included in the method, such as a stage for pulling the running tool 200 and control device 110 out of the subsea structure 400. This may include a step of commanding the control device 110 to control an adaptation of the running tool 200 into a moving configuration, in which the running tool 200 has all its moving parts retracted.
Generally, the terms used in this description and claims are interpreted according to their ordinary meaning the technical field, unless explicitly defined otherwise. Notwithstanding, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. These terms are not interpreted to exclude the presence of other features, steps or integers. Furthermore, the indefinite article “a” or “an” is interpreted openly as introducing at least one instance of an entity, unless explicitly stated otherwise. An entity introduced by an indefinite article is not excluded from being interpreted as a plurality of the entity.
The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the invention in diverse forms thereof.
While the invention has been described in conjunction with the embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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20211390 | Nov 2021 | NO | national |
This application is the U.S. national stage application of International Application No. PCT/NO2022/050261, filed Nov. 15, 2022, which international application was published on May 25, 2023, as WO 2023/091022 A1 in the English language. The International Application claims priority to Norwegian Patent Application No. 20211390, filed Nov. 19, 2021. The international application and Norwegian application are both incorporated herein by reference, in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/NO2022/050261 | 11/15/2022 | WO |