New oil development technology, developed over 30 years on Alaska's
North Slope, will allow companies to tap underground producing reservoirs
with a much smaller "footprint" on the surface.
When Prudhoe Bay was developed in the 1970's, about 2 % of the surface
area over the field, or 5,000 acres, was covered by gravel for roads and
drilling and production facility sites. If Prudhoe Bay were developed
today, using lessons learned since the 1960's, gravel would cover less
than 2,000 acres, a 60 % reduction.
Advances in directional, or extended-reach, drilling now allow producing
companies to reach a reservoir three miles from the surface location.
Soon "extended reach" wells out to four miles will be possible on the
North Slope. When Prudhoe Bay was first developed, wells could reach out
only one and a half miles.
In the 1970's, production wells on drill pads in Prudhoe Bay were spaced
100 feet or more apart. New directional drilling techniques and drill
equipment allow wells to be spaced 25 to 15 feet apart, and in some cases
10 feet apart. A drill pad that would have been 65 acres in 1977 can be
less than nine acres today. The same number of wells that required a 65-acre
pad in the 1970's can be drilled on less than a nine-acre pad today.
Drilling Mud Disposal
New technology allows producing companies to do away with reserve pits
for drilling fluid ("mud") and cuttings. Mud and cuttings are now injected
the below-ground through disposal wells.
Ice Roads and Drilling Pads
Instead of building a gravel pad for exploration drilling, companies are
now building temporary pads of ice, which disappear after the exploration
well has been drilled. Temporary ice roads have long been used to support
winter exploration drilling on the North Slope.