Remote-Operated Tool (ROT)

  1. Subsea
  2. Production Engineering
  3. Production Facilities


ROT Configuration

A ROT is mainly used for module replacement/change-out and flowline tie-in, both of which require a handling force larger than that of an ROV. ROTs are usually deployed on liftwires or a combined liftwire/umbilical, and the lateral guidance is powered by an umbilical with dedicated thrusters, ROV assistance, or guidewires.
Sketch of Rot System

The ROT system should provide for safe locking of the replacement module during handling, deployment, normal operation, and emergency conditions such as power failure. There are three generations of ROT for tie-in tools:

  • A first-generation ROT is two separate tools that pull in and connect individually.
  • A second-generation ROT is a combined tool that pull ins and connects together.
  • A third-generation ROT is an ROV-mounted pull-in and connection tool.

The ROT system should provide for safe locking of the replacement module during handling, deployment, normal operation, and emergency conditions such as power failure. There are three generations of ROT for tie-in tools:

  • A first-generation ROT is two separate tools that pull in and connect individually.
  • A second-generation ROT is a combined tool that pull ins and connects together.
  • A third-generation ROT is an ROV-mounted pull-in and connection tool.

Pull-In and Connection Tool

In this section, basic information about a pull-in and connection tool is provided. The pull-in and connection system includes the following main equipment:

  • Connectors with seal assemblies. Connector type determines the required function of hydraulic supply, torque tools, integrated seal plate handling, and replacement tools;
  • Pull-in and connection tools;
  • Hubs, caps, and terminations;
  • Pull-in porches/alignment structures for interfacing with subsea structures.
    Collet Connector (Courtesy of cameron international)

The following are the main procedures required to make a connection:

  • Rough alignment between inboard and outboard hubs, approached by pull-in tool or guiding funnel;
  • Precise alignment after two hubs mate, completed by the connection tool;
  • Connection by connecting tools (e.g., jacking screw operation by torque tools, and seal pressure test by ROV).
    Clamp Connector (Courtesy of Vector International)
    Pull-In and Connection Tool(Courtesy of Alker Solutions)

Component Change-Out Tool

A component change-out (CCO) tool is used to recover and reinstall subsea modules such as:

  • Chokes;
  • Valves;
  • Multiphase meters;
  • Subsea control modules;
  • Chemical injection modules;
  • Pig launchers.

A CCO is often deployed by the guideline method or as a fly-to-place tool. It can be deployed to the seabed in an individual basket using the fly-toplace method, and the ROV with interface skid can dock onto the CCO and establish control of the CCO with, for example, the electrohydraulic stab plate connector. The ROV will then unlock the ROT from the basket, fly it to place, and dock onto the subsea structure.

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


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