Today’s global mooring industry is facing a significant test with the need to balance the complexity of mooring operations and technology innovations against managing costs and increasing efficiencies in a difficult market environment.

Developments have included a transfer of many responsibilities from operators to rig owners in areas such as procurement and installation, while declining floating rig utilization rates have seen many owners faced with a growing number of idle units (as of May 2016, industry analyst Quest Offshore Resources counted 126 idle rigs globally).

Against such a backdrop, the mooring industry is facing both operational and cost challenges as well as a need for providers to stand out from the crowd in what is a highly competitive market.

With newer operations taking place alongside older infrastructure such as in the North Sea, mooring arrangements must be more precise and accurate than ever before.

Operations

On the operational side, regular challenges include the need to navigate around existing subsea infrastructure such as pipelines, wellheads and umbilicals. With newer operations taking place alongside older infrastructure such as in the North Sea, mooring arrangements must be more precise and accurate than ever before.

There is also the need to safely secure drilling units in challenging environments, with many rigs often operational in the majority of weather conditions. This requires flexibility in deployment to meet dynamic environments, not just in regard to weather conditions but also in relation to fatigue, wear and corrosion of equipment, all of which can fluctuate over time.

Linked to this, mooring integrity, inspection and monitoring, and the real-time tracking of mooring operations also have come to the fore. Recently, Oil & Gas UK issued updated guidelines on mooring integrity with the support of operators, contractors and vendors.

There is a demand in particular for the real-time monitoring of mooring systems both in their deployment and to track their condition.

There is a demand in particular for the real-time monitoring of mooring systems both in their deployment and to track their condition. A lack of monitoring and tracking can lead to mooring line replacement or failure and, if mooring is not tracked in real time, operational dangers such as damage to risers, production or drilling shutdowns, or even small hydrocarbon leaks.

In such cases, effective monitoring and data management— ideally without the need for costly maintenance or subsea sensors—is necessary to detect mooring line failure and ensure continued mooring systems integrity for the lifetime of the asset.

Cost

Balanced against these challenges is the pressure to ensure a continued focus on greater effi ciencies and reduced costs while still adhering to the highest standards of safety and asset integrity.

As mooring operations become more complex, the visibility of assets has become increasingly important to reduce costs and risk in operations, linking in to the importance of real-time monitoring.

In addition, every day a rig is in transport is a day lost to drilling. With support vessels such as anchor handling vessels costing up to $15,000 per day (well down from recent years but still a substantial cost), faster mobilization and reduced drilling costs are vital. In such cases, prelaid mooring systems are becoming more popular in the current downturn.

Finally, operators and rig owners need access to a complete mooring solution with fast deployment and transportation. From the latest in new anchors to buoyancy units, mooring chains or synthetic fi ber mooring rope, operators ideally need economies of scale and a single provider.

Australian mooring solution

So are mooring technologies and mooring providers meeting these challenges?

A good example of how these challenges are being addressed can be found in Global Maritime Deep Sea Mooring’s recent provision of mooring and rig positioning services to a leading Australian oil and gas operator. The contract represented the fi rst time all four sister companies of Global Maritime have been involved in an Australian operation.

The companies consist of Deep Sea Mooring, which offers offshore mooring services from prelay and rig move solutions through to marine engineering and mooring equipment rental; Global Maritime Vryhof, a leader in anchoring; Global Maritime MoorLink, which designs, produces and installs certifi ed swivel links, connections and wire clamps for use on any chain, wire or rope; and Global Maritime Consultancy & Engineering, a marine, offshore and engineering consultancy.

In this case, mooring services were provided for a semisubmersible drilling unit offshore Australia where there was a need to navigate around existing subsea infrastructure. Furthermore, the rig also would be in operation during cyclone season.

12-point system

Global Maritime designed, engineered and supplied a 12-point mooring system, with the initial installation consisting of 12 prelaid anchors that were set and tension- tested prior to the arrival of the semisubmersible drilling unit.

The total mooring solution, when the rig was operational, consisted of eight 1,750-m (5,742-ft) mooring lines—a combination of chain, synthetic fi ber rope, rig chain, subsurface buoys and the relevant jewelry for connections. Four storm-mooring lines at 1,930 m (6,332 ft) were also made available to ensure maximum stability during the cyclone season (only eight mooring lines were used outside cyclone season).

In addition, high-strength MoorLink swivels were used to relieve the twist and torque that builds up in the mooring line, and 20-ton mK5 StevShark anchors from Vryhof helped facilitate performance in challenging soils. In this case, the mud line consisted of very silty sand and the formation sandy clay/silty clay. All products were mobilized quickly and effi ciently with minimal additional costs.

Finally, Deep Sea Mooring’s Advanced Distance and Positioning System (ADAPS) and Device Tracking and Control Systems (DTAC) were used. ADAPS is a tool for monitoring real-time anchor positioning—a crucial factor when the distance between the anchor and any subsea infrastructure is critical. It also potentially eliminates the need for ROV work during prelay operations and rig moves, resulting in cost and time efficiencies.

Through the use of a reinforced transponder fitted to the anchor to monitor its position and seabed penetration during installation, the ADAPS helped attach the anchors prior to deployment of the semisubmersible drilling unit. The technology also ensured that the anchor landed in the required position and provided information on its pitch and roll along with the depth of penetration. The DTAC also provided desktop tracking and buoy position monitoring prior to the rig’s arrival. The end result was a successful mooring deployment.

Equipment traceability

One other mooring technology innovation is a newly patented radio-frequency identification marking system that can be found on all Deep Sea Mooring equipment. The system ensures complete traceability and identification of Deep Sea Mooring equipment and increased efficiencies. The data are used to track mooring equipment, leading to an accurate usage history of equipment, and ensure that any material inconsistencies or unexpected loading effects are addressed immediately.

In addition, less effort, time and cost are required to handle equipment, and there is also a reduction in operational time during prelay operations and rig moves. Deep Sea Mooring is already collecting data on the sequence in which the equipment is deployed to the seabed to further reduce paperwork and risk from human error.

The result is increased levels of visibility in mooring operations, a reduction in operational time and risk, and a positive impact on safety and efficiencies.

At a time of increased offshore complexity and the industry’s heavy focus on efficiency, mooring providers are being tested like never before and need to deliver value-adding solutions like those above to help operators address these challenges head on.

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