Creating Rov interface Requirements
To facilitate subsea interventions such as drilling assistance, installation assistance, and inspection, maintenance, and repair (IMR) by ROVs, interfaces are introduced and produced for ROVs:
- Hydraulic work package and docking frame for the ROV itself;
- Hydraulic connector, valve override tool, and adapter for the ROV manipulator; and also for subsea equipment to facilitate
ROV application:
- X-mas trees fitted with a valve panel;
- Manifold valves fitted with a guidance system;
- Modules and tools equipped with a local control panel. This section describes the requirements for the typical interfaces and is based primarily on API 17H.
Contents
Stabilization Tool
The stabilization of ROVs can be achieved in the following ways:
- Working platform, formed by utilizing part of the subsea structure;
- Suction cups, consisting of an arm attached to the ROV and a suction cup on the end of the arm which may be used when the ROV carries out manipulator operations such as cleaning, inspection, and individual valve operation;
- Grasping, which can be widely used for all items of subsea hardware;
- Docking, used with a single- or twin-docking tool deployment unit (TDU) together where the loading of a subsea equipment interface is not desirable. The receptacle is incorporated into the structure of the subsea equipment, whether as a separate bolted or welded-in unit, or incorporated as part of the subsea equipment.
The interfaces should satisfy following requirements:
- Working platforms for ROVs should be flush and free from obstruction.
- The subsea structure should be a flat surface broadly adjacent to the task area for the use of a suction cup for stabilization purposes.
- Grasping intervention interfaces should be designed to withstand a minimum force of 2.2 kN (500 lbf) and a gripping force of 2.2 kN (500 lbf) applied from any direction.
Handles
Handles are the interface between tools such as torque tools or hot stabs and the ROV manipulators or ROV-mounted tool TDU The interface should satisfy following requirements:
- The stem of handles should be capable of resisting the maximum operational
forces regardless of whether they are linear forces or rotary forces.
- Any out-of-line forces generated by the operator in linear applications have to be taken into account by the compliancy between the handle and the attachment to the tool.
- The handle should be marked to display the direction of movement of the handles to reduce the probability of damage.
The interface can be operated by anROV-mounted toolTDUormanipulator
Low Torque
This interface provides for ROVoperation of ball and needle valves, clamps, etc. The interface on the subsea equipment comprises a paddle or T-bar enclosed in a tubular housing, as shown in the following figures, which may be incorporated into a panel by bolting or welding, be free standing, or be made as part of the subsea equipment.
High Torque
High-torque interfaces provide for the ROV operation of tree valves, clamps, satellite control module (SCM) lockdown, shackle release, etc.
The interface should satisfy the following requirements:
- If the interface receptacle is incorporated into a panel, the panel should be flush with the docking face.
- The interface should be manufactured from material with a minimum tensile strength of 450 MPa so that it can be operated at the specified torques.
- Protection from marine growth and corrosion are necessary in most environments, so the use of corrosion-resistant materials or appropriate coatings should be considered.
- Access is required in the area along the drive stem axis.
Hydraulic Connection Tool
The hot stab/hydraulic connection tool interface provides for ROV typical operation of valve actuation, seal and connection testing, chemical injection, planned or emergency release, and fluid collection. The connection allows pressurization between two isolated sections separated by seals. The interface should satisfy the following requirements:
- The female receptacle, permanently mounted to the subsea system, should be manufactured with corrosion-resistant materials making it suitable for long-term immersion in seawater. File:High-Torque Tool per API 17D (Courtesy of Fugro-imp ROV Ltd.).pngHigh-Torque Tool per API 17D (Courtesy of Fugro-imp ROV Ltd.)File:Male and Female Mating Halves of a Hot Stab Hydraulic Connection.pngMale and Female Mating Halves of a Hot Stab Hydraulic ConnectionFile:Hot Stab (Courtesy of Nemo Offshore Pty Ltd.).pngHot Stab (Courtesy of Nemo Offshore Pty Ltd.)File:Hot Stab (Courtesy of Tool Marine Technology Pty ltd.pngHot Stab (Courtesy of Tool Marine Technology Pty ltd.
- The hot stab receptacle should be designed so that it does not fill with debris while not in use.
- The hot stab should have a flexible joint in the handle or stab to ease connection and disconnection activities.
- The receptacle should be self-sealing and watertight when uncoupled.
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Linear Override Tool
The ROV interface is primarily/typically for the ROV operation of hydraulic gate valves open after fail-safe closure, where it may be incorporated as part of the valve actuator. The linear override tool (LOT) interface tool is used to transmit the axial force to the stem of hydraulically actuated gate valves. The interface on subsea equipment comprises a flange around a central stem, and it can be operated by the LOT handled by an ROV-mounted tool (e.g., ROV þ TDU/manipulator). The interface has to satisfy the following requirements:
- The interface flange should endure the load induced by the maximum push force based on that required to open gate valves at full differential pressure and should be manufactured from material with a minimum tensile strength of 450 MPa to operate at the above loads.
- Protection from marine growth and corrosion is necessary in most environments, so the use of corrosion-resistant materials or appropriate coatings should be considered. File:Linear Actuator Override Tool (Courtesy of Subsea 7 Inc.).pngLinear Actuator Override Tool (Courtesy of Subsea 7 Inc.)File:Linear Push Type A interface.pngLinear Push Type A interface
- It is important to check the stroke on the TDU to ensure sufficient clearance to fully make up the linear push device and to subsequently remove it.
- Access is required in the area along the drive stem axis.
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Component Change-Out Tool (CCO)
The ROV interface provides for ROV operation for the replacement of control pods, chokes, multiphase meters, etc. The ROV interface should satisfy the following requirements:
- The top face of the landing units should be positioned flush with or above the component lifting mandrel.
- Design loads for the landing units are particular to the component and should be evaluated on a case-by-case basis.
- The landing units may be structurally supported from either the structural framework or from the component base unit. The clearance required for weight transfer units should be taken into account the support arrangements. File:Component Change-Out Interface.pngComponent Change-Out Interface
Electrical and Hydraulic Jumper Handling Tool
This ROV interface provides for the ROV operation of installing the electrical flying lead, steel flying lead for transporting hydraulic fluid, and stab plate of the assembly of electric connectors or hydraulic couplings or both. A single-connection interface handling tool can be operated by either a manipulator or TDU, whereas a multiple quick connect (MQC) stab plate can be operated by a TDU or a combination of manipulator and tool elevator. An oil-filled hose conduit connection interface can be used for a single connection.
The MQC interface should satisfy the following requirements:
- The material specification, plate shape, and thickness should be able to resist the maximum operational forces.
- A release mechanism should be incorporated for the inboard locking assembly in the event of stab plate jamming.
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References
[1] American Petroleum Institute, Remotely Operated Vehicle (ROV) Interfaces on Subsea Production Systems, first ed., API-RP-17H, 2004.
[2] American Petroleum Institute, Remotely Operated Tool (ROT) Intervention System, first ed., API- RP-17M, 2004.
[3] Norwegian Technology Centre, Remotely Operated Vehicle Services, Rev 1, NORSOK standard U-102, (2003).
[4] Norwegian Technology Centre, Subsea Intervention Systems, Rev 2, NORSOK standard U-007, (1998).
[5] J.R. Gert, Challenges and Experience in ROV-based Deepwater Seabed Mapping, OTC 13158, Offshore Technology Conference, Houston, Texas, 2001.
[6] Deepwater Corrosion Services Inc, http://www.stoprust.com.
[7] Specialist ROV Tooling Services Ltd., http://www.specialistrov.co.uk.
[8] Subsea 7, http://www.subsea7.com.
[9] Saab Seaeye Limited, http://www.seaeye.com.
[10] C.I. Davis, E.B. Lallier, C.L. Ross, Protective Deployment of Subsea Equipment, OTC 15089, Offshore Technology Conference, Houston, Texas, 2009.
[11] Schilling Robotics, LLC. http://www.schilling.com.
[12] SMD Robotics Ltd. http://www.smd.co.uk.
[13] Sub-Atlantic. http://www.subatlantic.co.uk.
[14] Canyon Offshore Inc. http://www.helixesg.com
[15] Fugro-ImpROV Ltd. http://www.improvltd.co.uk
[16] Nemo Offshore Pty Ltd. http://nemo-offshore.com.au
[17] Tool Marine Technology Pty Ltd. http://www.tmtrov.com.au/index.asp
[18] Cameron International Corporation. http://www2.c-a-m.com/index.cfm
[19] Vector International. http://www.vectorint.com/
[20] Alker Solutions. http://www.akersolutions.com/Internet/default.htm
