U.K. North Sea operators see plenty of life left in mature play

The U.K. oil and gas industry is convinced it has a bright future despite current abandonment programs in some of its older offshore fields.

The U.K. Offshore Operators Association (Ukooa) has published a report, "Towards 2020," that predicts oil production will continue at its current rate for 10 years, and significant production levels will continue for another 20 years.

Here are Ukooa's main conclusions:

U.K. oil production is headed for a peak of 2.9 million b/d in 1996-97, after which it will decline slowly to about 1 million b/d by 2020.
U.K. gas production potential is rising and will plateau at 10-11 bcfd during 1998-2004, after which it will decline to about 4 bcfd by 2020.
Total capital and operating outlays will remain at 8-10 billion ($12-15 billion)/year for the next 10 years, with half the spending destined to maintain existing infrastructure.

Bryan Taylor, Ukooa's director of technical affairs, said there have been 187 oil discoveries to date off the U.K., as well as 133 gas and 41 gas/condensate discoveries.

The discoveries hold combined reserves estimated at 27 billion bbl of oil and 83 tcf of gas, of which 13 billion bbl of oil and 35 tcf had been produced by the end of 1995.

What's left to find

Mathematical modeling has shown 130 discoveries remain to be made off the U.K., while 240 new development projects are possible from discovered and undiscovered reservoirs.

Ukooa reckons U.K.'s undiscovered resources amount to 2.4 billion bbl of oil, 13.7 tcf of gas, and 600 million bbl of condensate.

Taylor said, "Improved expectations from producing fields account for two thirds of the 5 billion bbl of oil equivalent added to reserves since our similar study in 1989."

"Since the last study we have better 3D seismic and better long reach drilling, and we have made tremendous efforts to reduce operating costs so fields can remain in production for longer than expected.

"The future will be dominated by smaller developments, with the emphasis on subsea and floating production systems. New field developments now have average reserves of 40 million bbl of oil equivalent, compared with 60 million bbl in 1989."

Taylor said operators reported few discoveries of less than 10 million bbl in the previous study, whereas this time many new reservoirs of only 2-3 million bbl of oil equivalent were listed.

"This shows operators are confident they can capture these small bubbles of oil and gas and develop them while the current infrastructure is in place," he said.

Subsea and floater systems account for about 75% of development projects being planned.