The U.S. Beaufort Sea may hold the largest undiscovered oil deposits which could account for up to 25% of the world's undiscovered hydrocarbons based on the article of "Science." Therefore, there are strong interests for oil and gas industry to explore these enormous reserves of oil and natural gas in order to meet the long term increasing energy demands.
In Beaufort Sea, an averaging water depth is about 800m which is normally called deep waters. An exploratory well typically takes about five to six months for continuously drilling in shallow waters. Beaufort Sea has an average two-month open water window, thus an exploratory well will take two to three years to complete if only seasonal drilling is considered. In deep waters, it is much more complicated and challenging and will take a few times longer than drilling in shallow waters. Seasonal drilling for deep waters is practically and economically prohibited. Year-round drilling capability is a truly required feature. To have year-round drilling ability, hull and mooring has been designed to withstand ice actions of first-year ice, ridge and up to multi-year ridges depending on disconnection criteria. In Beaufort Sea, it is practically impossible to design the floater to stay in-place for 30-year service life for any ice actions. Thus, dis-connectable ability is another desired feature when a sizable iceberg or unmanageable ice feature is approaching.
As of today, there are a few dis-connectable concepts had been proposed, such as disconnectable FPSO, non-ship-shaped circular FPSO, arctic Spar and semi-ridge floater. These concepts are either designed for benign ice conditions or intended just for seasonal drilling and production. So far, no floating drilling and production facility has been installed with year-round operation capability in Beaufort Sea. It strongly calls for development of alternative dis-connectable arctic floating platform concept to explore mega reserves in deep waters of cold regions. This paper presents HOE persisting efforts for developing innovative arctic floating platform concept having above mentioned features in past six years. A preliminary disconnection procedure of HOE arctic floater for drilling and production is outlined as an example.