Mat Bateman takes a look at Dynamic Positioning (DP) and the challenges and solutions that are present in today’s marketplace

Dynamic Positioning (DP) has transformed offshore oil & gas operations and other applications, such as construction, supply, diving, and shuttle tanker operations. For instance, while jack-ups and moored drilling units were previously limited in their areas of operation, DP technologies – using computer controlled systems that maintain a vessel’s heading and position – have enabled operators to drill and produce at greater depths and in most conditions.

Previously, moorings were used, with applications limited in depth, engineering design for each location, and vulnerability in severe weather. A DP vessel, on the other hand, can simply terminate operations and depart.

Examples of DP operations that Global Maritime has undertaken over the last few months include a multiple analysis of DP mandatory documentation for Australian operator Woodside Petroleum; a DP assurance inspection for offshore services supplier Vroon Offshore; and a DP Failure Mode and Effect Analysis (FMEA) for a Helix Q7000 drilling rig in Singapore.

Not risk-free
However DP is not risk-free. Control systems and their ancillaries are only as good as their design, maintenance and operation with deficiencies leading to thrust failures, unwanted thrusts and damage to equipment, personnel and the environment. Class-approved DP Systems at equipment Class 2 or Class 3 (DP2/DP3) are designed so that any single failure will not cause a loss of position and there are mechanisms and tools that provide assurance that the DP System meets these requirements. Yet as DP technologies have progressed, so have the challenges. This article will look at particular challenges and measures to mitigate and manage these risks.

Challenges facing DP – laid up staff & a declining knowledge pool
While the long-term demand for DP is likely to remain strong, the last 18 months have seen an industry slow-down with staff levels reduced, skill sets dispersed and some staff permanently leaving the industry.

With DP training taking longer than many offshore specialisms, there is a potential shortage of skilled DP expertise available when demand – particularly for DP mariners – returns.

Whilst we can have good visibility and knowledge of vessels available, it’s less clear where the suitable manpower will come from to man the vessels. Unlike a standard merchant vessel, a modern DP vessel is designed to work in specialist niche areas and DP mariners will need appropriate skills to understand and relate to the vessel and its capabilities. Many specialist DP vessels have previously operated with returning crews familiar with the vessel. Thus, there is a concern that this ‘ship knowledge’ will be lost with such unfamiliarity increasing risk.

Just as staff has been laid up, so have DP vessels. In years gone by, a laid up vessel could be simply stacked in a cold state with riding squads periodically passing by and running equipment. Today’s modern fleet, however, operates using primarily programmable electronic devices, such as DP computers, and much of the thrust development is from sophisticated power electronics devices.

Just like a computer or tablet that is turned off and left in an uncontrolled environment for an extended period, there is a danger that the communications and computers won’t start immediately or work. Industry groups have recognised this issue and guidance is being prepared by the MTS (Marine Technology Society).

Vessel owners and operators need to grasp these re-activation challenges and allow time to bring vessels back online with appropriate testing to ensure performance and robustness.

The dangers of bad assurance
In re-activating vessels, it’s also likely that many stakeholders will be involved from an assurance perspective. Despite the wealth of knowledge available on the subject from Class, the IMCA (International Marine Contractors Association) and MTS, standards of assurance vary greatly not only between organisations but within them.

Bad Assurance has two outcomes: The vessel is allowed to work when it shouldn’t, giving rise to risk; and the vessel is not allowed to work when it should.

Addressing these challenges
So how can these challenges be addressed? In short, mechanisms must be put in place to minimise risk.

Firstly, understand and plan how DP competent mariners can be sourced with the correct skill set for the niche the vessel is working in. Once sourced, allow staff new to a particular vessel the time to become familiar with the ship and test systems to ensure performance and robustness. Training will often be required.

Secondly, plan enough time to re-activate systems and test equipment, allow for the possibility of equipment failing, and assess the criticality of spares that may be vulnerable – batteries, for example.

Finally, develop an assurance plan to ensure that performance can be verified prior to deployment. The plan should be detailed and specific and developed in-house or externally.

Also bear in mind that regulations may require additional testing if a Class notation or mandatory body certification has lapsed. Ensure all stakeholders are agreed on the assurance plan ahead of time to enable buy-in.

New challenges, new solutions
Despite the market slowdown, the long-term outlook for DP is positive. According to a 2015 report by Markets and Markets, the global DP systems market is expected to reach $1.48 billion by 2020 with, despite the decline in oil prices, the market having ‘enormous potential for new technological advancements and expected to grow.’

Planning ahead and understanding the challenges to be faced will be critical in ensuring DP missions can be completed safely, efficiently and first time.

Mat Bateman works at Global Maritime. Global Maritime specialises in marine warranty, dynamic positioning and engineering services in the offshore and marine sectors. Founded in 1979, headquartered in Stavanger and majority-owned by HitecVision, Global Maritime’s services span the entire offshore project lifecycle from engineering & design, construction and third party verification through to marine warranty surveying, dynamic positioning, installation, risk management and decommissioning.
http://ce.globalmaritime.com