This paper provides an introduction to a joint industry project (JIP) which plans to employ coiled tubing (CT) from the deck of a vessel to deploy and install anchor points for mobile offshore drilling units requiring deepwater moorings.

CT offers significant advantages for installation of anchor points. It is a rapid conveyance means to the seabed; in addition it can supply significant power for drilling and is a circulation means once there. It provides the means for deploying anchors to considerable depths in the seabed, as appropriate to provide the necessary retainment force.

The vessel can then immediately perform a proof load test on the mooring line to ensure the quality of the anchor point. Only if it meets the required capacity is the CT then disconnected and recovered back to the vessel to collect the next anchor assembly and mooring line. To unset the anchor point, the mooring line is pulled taut and a release tool is dropped down the mooring line, close to the seabed, to activate a release mechanism which allows the mooring line to come free.

The concept offers many advantages over conventional anchors, including:

Pin point accuracy with reference to the mooring pattern centre.

Rapid and accurate anchorage deployment to significant depths into the seafloor

Very high ratio of pull-out force to weight of anchor equipment

Reduced difficulties in transportation and handling and therefore increased safety for anchor handling personnel.

Significantly reduced CAPEX and OPEX.

Simple recovery of anchor and mooring line when released from rig.

You can access this article if you purchase or spend a download.