GHX-2: jump-starting Prudhoe Bay.

AuthorTyson, Ray
PositionNorthern Slope gas-handling modules

The new gas-handling (GHX-2) modules on the North Slope will extend the life of the northern oilfields.

With crude production largely on the wane during the first half of 1993, the early arrival of this year's sealift on the North Slope brought welcomed relief to producers. On board were a dozen modules aimed at giving Alaska's largest oilfield at Prudhoe Bay a much-needed shot in the arm.

In fact, project coordinator Arco Alaska expected to have the so-called GHX-2 gas-handling modules installed and operating by the end of September, weeks ahead of schedule. GHX-2 will give Prudhoe Bay output a temporary boost of 100,000 barrels a day, half of which will come this year and half in late 1994, after the remaining modules are delivered to the North Slope next summer.

Actually, the $1.2-billion GHX project is designed to keep Prudhoe Bay production, in natural decline since 1988, from plummeting while extending the life of North America's most prolific oil reservoir. Through GHX-1 (completed in 1990) and GHX-2, Arco estimates an additional 800 million barrels of oil can be recovered over the field's lifetime.

As the Prudhoe Bay field grows older, more natural gas rises to the surface with the oil -- a natural phenomenon that inhibits oil production because of the difficulty in dealing with large volumes of gas. GHX-2 will increase daily gas-handling from 5.2 billion cubic feet a day to 7.5 billion cubic feet a day, most of which will be reinjected into the field's gas cap. The gas also serves to maintain reservoir pressure.

"The natural evolution of producing a reservoir is decline over time. We're trying to arrest that decline, and the best we probably can do is to create a momentary leveling off of that before we continue the decline," explains Charlton Breon, a member of Arco's GHX-2 design team.

Prudhoe Bay production has fallen from an annual average peak of 1.6 million barrels a day to just over 1 million barrels a day but still represents roughly three-quarters of North Slope output. Without the GHX project, field production would be plummeting at the rate of 6 percent to 8 percent a year.

Nevertheless, total Alaska North Slope (ANS) production -- representing 85 percent of state revenues and 25 percent of the U.S. domestic oil supply -- was well below forecasts going into the third quarter of this year. In July, for example, ANS yields dropped to 1.447 million barrels a day, the lowest monthly average in 13 years. And for the first...

To continue reading

Request your trial

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT