US: Heavy oil could lengthen North Slope's production life

THE GIANT oilfields of Alaska are showing their age. Production from reservoirs on the North Slope, which began in 1977 and peaked at 2m barrels a day (b/d) in the late 1980s, had dropped to about 450,000 b/d by year-end 2004. To help offset this decline, North Slope producers are attempting to exploit the heavy-oil deposits that overlay the fields' main producing zones. What makes the North Slope's heavy oil so attractive? It is abundant: the West Sak, Schrader Bluff and Ugnu heavy-oil formations could contain as much as 36bn barrels of original oil in place – as much as Alaska's two biggest fields, Prudhoe Bay and Kuparuk, combined. It is also close to the existing infrastructure. Once ext