Working on top of the world: Part 2

Pipeline design

The industry’s response to many design issues relating to offshore platform or vessels, in terms of the Arctic’s environmental conditions, is well advanced. In ice-affected areas of moderate water depth, ice scour from ridges and icebergs (also known as stamukhi in some Arctic areas) impact the design of seabed infrastructure, such as wellheads, Christmas trees, flowlines, umbilicals and pipelines.

The design of a pipeline’s shore approach is much more problematic in areas with sea ice. The reasons can include near-shore environmental sensitivity, coastal regression, permafrost and the requirement for deep burial to prevent damage from ice gorging in the shallow water areas.

Most of the land surrounding the Arctic Ocean is underlain by permafrost. Permafrost is a significant issue for pipeline design; operational issues such as heat input from a buried pipeline carrying a warm fluid can cause subsidence of ice-rich permafrost, resulting in excessive stresses in the pipe wall.

In the shallow ice-infested waters in the Arctic region, subsea equipment and pipelines areas are subjected to gouging ice keel features from ice ridges, stamukhi and icebergs. While in many cases the solution may be to apply a greater burial depth, this may be extremely costly or difficult to construct due to complications with permafrost, trenching equipment or a confined operational envelope.

Operational challenges for subsea pipelines include issues such as monitoring and leak detection, and pipeline repair. Flow assurance for long tie-back distances is also a design step requiring special attention in the Arctic.

Human factors

Human performance could be seen as one of the most important risk factors when taking decades of experience of transporting oil and gas around the world and applying it to transportation in a cold climate. It is logical to expect that most maritime operations are more difficult to execute correctly in low temperatures and in icy conditions. In such conditions, experienced crew are required in order to maintain the same safety level as expected in typical worldwide operations. When dealing with extreme cold climates such as the Arctic, special considerations for safety, environmental protection and operation are required, for example:

• Crew condition and training to react and function efficiently in low temperature environments.
• Suitability of the vessel design.
• Requirements to maintain vessel operability in ice and in low temperatures.
• Cargo handling routines and safety functions.
• Emergency response including fire fighting arrangements, evacuation (for example life boats), and emergency towing arrangements.

Extreme low temperatures, limited daylight during winter periods as well as noise and vibrations from navigating in ice, can lead to reduced rest quality when the crew is off duty. Crews on ships and platforms are likely to be isolated. The resulting exhaustion may lead to increased likelihood of accidents and with greater consequences. Research into the challenges and effects on risks posed by the conditions, fatigue and related factors, is needed. Many studies have concentrated on the effect of wind chill and the various national regulations on working practices in low temperatures. Cold exposure can have detrimental physiological and psychological effects on humans (collectively termed cold stress).

Emergency response

It is the area of escape, evacuation and rescue (EER) that arguably presents oil and gas companies with the greatest challenges for Arctic developments, requiring innovative thinking to solve. In more mature regions, the overall risks from EER are now expected to be low and tolerable. Because of this history, and with a well-established supply chain providing standard EER equipment, many offshore developments in cold regions such as the Arctic continue to use traditional EER systems.

However, studies for many development projects have concluded that EER systems developed for temperate areas may not be suitable for the Arctic. The risk for personnel needing to leave an installation in an emergency could be significantly higher. With few Arctic developments having been completed to date, it may be some time before a consensus can be reached as to the optimum evacuation and rescue solution.Environmental response

Providing a means of responding to an oil spill in icy, inaccessible areas such as the Arctic presents a major issue, politically as well as environmentally. As the Arctic oil and gas industry covers several nations’ waters, with some areas under dispute, co-operation and decision support systems for environmental response and management in the Arctic are of particular significance. With the perceived near-pristine condition of the Arctic, and the role of the media in environmental breaches the industry’s Arctic developments are even more under the spotlight.

Research is needed to examine risk acceptance levels, decision support and management systems; in this area it will be important that regulations and standards can be harmonised as far as possible, and that potential environmental releases are managed to a level at least as high as those in other regions.

The opportunities in the Arctic, whilst extensive, are not without significant challenges. Given this extremely fragile and unique environment, companies involved in Arctic exploration have a responsibility to also preserve it for future generations. This can only be achieved by adopting the most rigorous of risk management processes, which push the boundaries of current methodologies, as well as geographical frontiers.

Written by John Yates, Marsh, UK, and edited by Hannah Priestley-Eaton

To read the full version of the article, please download a copy of April issue of World Pipelines

Read the article online at: https://www.worldpipelines.com/business-news/22082014/working-on-top-of-the-world-part-2/