The Arctic is an area of extraordinary beauty and complexity. It is a place where the extremes meet. It does not condone thoughtlessness. There has been no one in the history of its development who could achieve success “with a swoop”; only those who carefully planned their actions and weighed every step managed to succeed.
If someone a hundred years ago had mentioned in passing the recovery of oil or gas in the Arctic shelf, he or she would have been regarded as a day dreamer detached from reality at best. And even now the task is very complicated which is primarily attributable to the Arctic’s harsh climate and the variety of its conditions.
The Arctic is very cruel, but at the same time very vulnerable. Any trace left by a tractor, which disappears in a week in the Amazonian region, becomes a scar in the Arctic for many years to come. Not only does any inaccurate work cause harm to nature, but the destruction of nature, as a boomerang, comes back in the form of worse engineering conditions and rises in construction costs: the Arctic hits the careless and the greedy in the pocket. So to be successful in the Arctic, you need to study and comprehend it, to develop working practices that will preserve it, and then the Arctic will give you its riches.
The Arctic is very varied. It has rock islands and lengthy beaches barely lifting clear of the water surface. Glaciers and quick sand. Permafrost and breakable frost. Storm sea and ice islands.
The Arctic has both coasts with very high tides, as in the White Sea, and places where they are very hard to notice, for instance, near the northern islands. The bottom of the Arctic shelf can also be diverse – rocky and muddy, almost semi-liquid. Ice conditions are also sundry: it is possible to lay pipes from ice sheets in some places; in others there is a rather long period of time when the sea is iceless.
It is therefore simply impossible to say that there are some standard and general solutions for the Arctic. Each sea, even on different coasts, requires its own solutions, approaches and methods. There is only one common thing: any construction will ask for long-term and laborious engineering surveying. And the quality of work – from pipe production to pipe laying – should be exceptional.
Even though we often speak about the riches of the entire Arctic region, it needs to be understood that many Arctic regions are economically unapproachable as of now. These are treasures that can be reached only within decades. In view of this, the southern part of the Barents Sea and the central and southern parts of the Kara Sea are of the most practical interest. And the history of construction of the first Russian marine pipelines began there.
The Kara Sea derived its name from the eponymous river that runs into the Baydaratskaya Bay. However it is just one of the many versions. In the west the Kara Sea is enclosed by the Novaya Zemlya archipelago, and in the east – by the Severnaya Zemlya islands. The sea is mainly shallow, and there are not many places where the depth exceeds 100 meters. The southern part is uniform shallow waters. In the days of great glacierization when the sea level was substantially lower than it is now (by several dozens of meters), the greater part of the Kara Sea’s bottom was land.
And even now the Kara Sea’s bottom has ancient permafrost that poses a serious problem for the laying of bottom pipelines since it is necessary to account for its impact both upon a pipeline and products pumped through it. In essence, it is a refrigerator that is not advisable to defreeze. In other words, in such places as the Baydaratskaya Bay, it is necessary to account for the factors at the sea bottom which usually exist only on permafrost land.
For most of the year the sea is covered with glaciers. And, as a result of hummocking, there emerge huge ice chunks which, being transported by flows, plough near-shore deposits. Coasts are rich in frozen soil; quick sand, which is activated by an intertidal process, is also not uncommon. Many massive objects left on beaches slowly but steadily disappear in sand right in front of your eyes. However there is yet another option: they can emerge because of washouts and changes of the coastal deposits’ profile.
In deeper places the sea bottom is represented by complex sandy and muddy soil with a very insignificant carrying capacity. Nevertheless, the deeper you drill into the sea bed, the more solid the soil. At first sight we can witness a very remarkable situation: it is much easier to erect a gigantic platform than to lay a pipeline.
Engineering surveying in the coastal area of the Kara Sea began back at the end of the 70s – the beginning of the 80s of the 20th century where the USSR was the first to think about the development of marine fields of the Arctic and Far Eastern seas. So there is no talk about the suddenness of this process. It was primarily connected with the prospects of developing fields on the Yamal Peninsula. It was then that people considered laying a pipeline through the Baydaratskaya Bay from the Yamal Peninsula to the mainland in order to avoid constructing a lengthy and complicated bypass.
Geological engineers had to answer the following questions asked by constructors: how do coastal and bottom deposits behave? What needs to be done with a pipeline – should it be sunken into the bay bed or can it be left on the surface? What will happen to bottom soil when it is frozen? Design engineers had to know the answers to such questions beforehand.
There were also many questions asked about the pipeline laying technology in similar water areas. There were initially some ideas about laying a pipeline on the ice surface, the so-called land-fast ice, and then submerge the pipeline to the bottom, gradually sawing the ice. It may look like a fantasy, but it is the elaboration of different options and the study of international experience (for instance, in the American and Canadian sectors of the Arctic) that helped choose the best solutions.
Everything is ultimately conditioned upon specific environmental conditions. That very same pipe can be laid on the surface of the sea bottom in certain fairly deep areas; it is expedient to work a pipeline deeper in shallow areas to isolate it from any possible impact of the ice. It goes without saying that it should be worked deeper to a required degree in places where it is on land in order to exclude any possibility of washing-out.
It is not easy on land either
There are many difficulties in the Arctic sea, but the Arctic land is no less complicated. Unfortunately, the Arctic soils are very complex, and the geography of the region can drive any engineer crazy. For one, it is an endless chaos of lakes, rivers and moors in summer. Permafrost is very close to the surface in some places, while in others it simply slumps into the depth.
In the most complicated places it is therefore more practical to lay a pipeline on piled foundations that are sunken into stable permafrost rock. However it is costly. In places where there are more stable and, what is more important, more homogenous engineering and geological conditions, it is possible to lay pipes both directly on soil with lateral padding and to bury them which is even more desirable for a number of reasons which include the decrease of seasonal temperature jumps and the decrease of any possibility of damage cause to a pipe, be it willful or unintentional.
The work in the north raises requirements to pipes themselves. If a pipe that lies on the sea bottom is affected by frost since the sea water cannot be cooler than -2°C, then gas pipelines placed on piers will be affected by very low temperatures. In view of this, engineers develop new ways of pipe winterization in order to decrease heat losses in winter. The development of new materials for very complex conditions is also under way.
Russian companies are currently working at full speed on the development of Yamal fields, from which the branches of new pipelines will go south. Far marine fields and their development are tasks for the future even in the most favorable market situation. It means that there is yet time to get prepared and to do it all in the best possible way.