Wednesday, July 28, 2010

the arctic and shell

royaldutchshellplc | Back in the early mid-1980’s Shell Oil began to take a serious look at the hydrocarbon production potential of the Chukchi Sea. They formed an operating division and staffed it with management, albeit with no staff, except secretarial support for the managers. (These guys were referred to ‘managers without portfolio’).

Shell’s exploration and production research division began to investigate the regions of the Chukchi Sea where potential lease sales were likely to occur. Of interest were the basic oceanographic parameters; water depths, under topography, sea floor surface geology, ice pack characteristics, etc. The basic surveys revealed some interesting results. The sea flow was basically covered fairly deeply with soft sediment (marine mud) but the topography was highly unusual. Acoustic mapping revealed an ocean bottom that was scarred by all sorts of crisscrossing trenches from a meter or so in depth, to almost 20 meters in depth.

At first these surface trenches were thought to be remnant features from the last ice age. But they appeared to relatively young. Arguments about their age and origin could not be settled with then available data. So, Shell obtained the cooperation of the US Coast Guard and ‘borrowed’ one of their icebreakers for a summer to do some detailed ocean bottom surveys and surface mapping. In addition a pattern of acoustic buoys were left upon the ocean bottom.

The next year the icebreaker with its compliment of Shell ‘boffins’ remapped the ocean bottom surface and set about looking for the acoustic buoys. They found some, many were never found. Those that were found had been displaced. And the topography of the ocean bottom had change completely. The old ocean bottom topography was gone, replaced by a new topography that had been sculpted by the dragging of the previous winter’s pressure ridges across the ocean bottom by surface winds and ocean currents. Some of the new trenches were almost 20 meters deep.

This news came as a very rude surprise to Shell’s leaders. Shell’s head office management turned to its talent pool at its research labs for an answer. Surely there must be an answer. Shell management wanted an engineering solution to the problem posed to development of oil and gas reserves by the Arctic ice.

After some degree of consideration it was recognized that the ice sheet itself posed problems, but those problems could probably be handled with creative design features to platforms or man-made islands. The pressure ridges however, were a whole different problem. Their size and extent made them a force of nature that could not be defeated. In shallow waters it might be possible to build rock and gravel production ‘islands’ that could be repaired after each winter’s battering by the ice. However, in deeper waters construction of these islands this was not a feasible solution. Man-made platforms of some sort would be required.

Short of the use of small nuclear weapons to ‘vaporize’ the problem posed by pressure ridges there was no ‘rational or practical’ engineering solution.