Technip: Lessons from Harsh Subsea Projs Applicable for Arctic Development

Subsea harsh environment projects carried out by Technip over the past decade, from Terra Nova and White Rose on the Grand Banks of Newfoundland to Snohvit in Northern Norway, provide valuable experience that can applied toward the development of projects for oil and gas development in the Arctic region, Technip reported last month at the Arctic Technology Conference in Houston.

The company considers these projects to be true stepping stones towards oil and gas development in the Arctic region. "The lessons learned from operations in harsh environments in relatively remote locations can be used to better prepare for any future operations undertaken in the Arctic," said Sam Allen, president of Technip Canada.

It is not necessarily the individual challenges offered by the various environmental elements that make working in such areas so demanding, but the combination of wave, current, wind, fog, ice, soils and short season make the subarctic and arctic a very unique area of the world to undertake offshore operations.

Generally, environmental data for frontier regions is lacking when compared to the mature oil and gas regions. "When the industry talks of exploration and production in the Arctic, the impression often given is that the Arctic is one homogenous region. In fact, the region is anything but homogenous and should not be treated as such." Instead, Technip has divided the Arctic into six regions, each with its own set of challenges.


Terra Nova, Lessons Learned

The Terra Nova project, conducted from 1997 through 2001, was the first-sub-arctic subsea mega project, the first to use large scale open glory hole construction for iceberg protection and the first to deploy a disconnectable riser system in a harsh environment. Terra Nova also was the first full field subsea development on the Grand Banks and the first floating production, storage and offloading vessel (FPSO) to be deployed in North America.

Technip said the flexible riser system for Terra Nova is one of the most challenging riser systems ever to be designed, including 15 flexible risers and four dynamic umbilicals in pliant wave configuration converging on an 18 meter diameter spider buoy for 95 meter water depth. The system is designed for a maximum wave height of 30.5 meters in connected mode. Technip successfully used knowledge learned from Terra Nova on the White Rose project.

Technip learned from its Glory Hole construction experience on the Grand Banks to use caution when selecting new technology for Arctic application. "Even the application of existing technology in new ways in these harsh environments should be treated with a high degree of caution. If you find a technology that works in Sub-Arctic and Arctic regions, stick with it. The sub-Arctic and Arctic are not places for experimentation."

Remote location is a key factor to be considered in the development of projects in both the sub-Arctic and the Arctic. Though Newfoundland now has a relatively well developed supply chain network, it is not nearly as extensive as the North Sea area network and in any case, the local area network often has to rely on the international network for its supply.

"As a result, the base cost of project execution is relatively high due to the higher cost of material procurement and the cost of getting expensive construction equipment to the project location. The reaction time of the supply chain is longer, and the cost of unplanned intervention is very high; for example, an additional construction is 15 days away and would cost millions of dollars to mobilize."

Technip encountered the challenge of distances between manufacturing locations and the project worksite on the Snohvit project, where Technip's workscope included the installation of more than 450 kilometers of product using one of Technip's reel-lay vessels, the Apache. The distance between Technip's Norwegian spoolbase and in Orkanger and the project worksite made multiple interim trips of the Apache to the spool base impractical. The solution was the development of a pipe transportation system allowing delivery of large volumes of rigid and flexible pipe to remote regions.

Locating workers on the project management and engineering team (PM&E) as close as possible to the work site is critical, allowing for better integration of the local supply chain and enabling a safer, more cost effective project by eliminating travel. For Technip to get one project engineer from its office in Paris to the offshore worksite at Sakhalin Island, it would take seven days, Allen said. As the industry pushes northward, it is envisaged that support hubs will develop adjacent to the frontier regions.

With increased water depth, a significant amount of the future field developments will be made through the use of subsea completions and longer tiebacks. Due to the environmental sensitivity of the area, there will be zero tolerance for spills and system and execution integrity will be critical. There will be a requirement for enhanced design considerations, even more rigorous project management and engineering, diverless operations and larger (more complete) lifts, Allen noted.

Construction vessels will require large decks, bigger cranes and faster transit speeds, and will need to be capable of operating in temperatures below -20 degrees Celcius for extended periods of time, and will require new tonnage.

Operating and maintenance of the installed system, especially during the long winter months will be a design driver and the use of autonomous vehicles for operating and maintenance will increasingly be a consideration. "There will be new, yet unforeseen, system design and construction challenges and offshore planning will become increasingly sophisticated. Development of the region will not be for the faint hearted and only the very top contractors will be able to respond to the challenges," Allen said.


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