Prudhoe Bay oil production passes 12 billion barrels.

• Author: Baker, Frank E.
• Position: SPECIAL SECTION: Oil & Gas - Reprint

When valves were opened to allow the first Prudhoe Bay crude oil to flow into the 800 mile-long trans-Alaska oil pipeline on the morning of June 20, 1977, everyone, including industry experts, didn't expect that North America's largest oil field would yield more than 9.6 billion barrels. Today, 35 years after startup, more than 12 billion barrels have been produced. This is about 53 percent of the estimated 22.6 billion barrels in place--and it's believed up to 2 billion more barrels are recoverable.

In cumulative production, the Prudhoe Bay field is now ranked No. 1 in the United States and 20th in the world.

In technical terms, the 12 billion barrel figure includes only the Prudhoe Bay Ivishak production from the Initial Participating Area (IPA), and includes all liquids such as black oil, separator liquids and natural gas liquids.

"The 12 billion barrels figure that we reached in October 2012 is consistent with the figures used initially to describe the original Prudhoe discovery and development," says Scott Digert, BP Alaska's reservoir management team lead. "It does not include the West End satellites (Aurora, Borealis, Orion and Polaris), nor does it include the GPB fields that come in through the Lisburne Production Center (LPC) such as Lisburne, Greater Point McIntyre Area, (GPMA) and Niakuk."

Boosting Production

Digert says that during the last three decades Prudhoe Bay has been a proving ground for oil field technology that has helped BP Alaska and other companies go beyond what was ever thought possible in maximizing production from the super-giant field.

"Advances in enhanced oil boosted our overall oil recovery by about 3 billion barrels," says Digert. "Large-scale gas cycling, water flooding around the periphery of the field, miscible gas injection (MI) and a technique called water-alternating gas (WAG) were effectively used. Improved reservoir analysis and delineation; advanced drilling techniques, such as horizontal and multi-lateral drilling; and advanced well completion methods, also made significant contributions."

To date, more than 1,000 wells and sidetracks have been drilled in the IPA, and with seven drilling rigs currently operating, BP Alaska plans to sustain its active drilling and sidetrack program in upcoming years.

"We're now aggressively going after light oil in known...