Conoco wants to expand West Sak

ConocoPhillips has applied to the Alaska Oil and Gas Conservation Commission, or AOGCC, for a vertical expansion by nearly 200 feet of the West Sak viscous oil pool in the Kuparuk River unit on the North Slope. The company says that the proposed expansion would bring the pool specification into alignment with equivalent geology in other North Slope viscous oil developments. The company also says that it wants to make a minor modification to the areal extent of the oil pool.

AOGCC has tentatively schedule a public hearing at 9 a.m. on April 1 to review the application.

The proposed vertical expansion will enable the development of a further West Sak sand interval in the Kuparuk area, ConocoPhillips told AOGCC. The company anticipates the possibility of recovering 85 million barrels of the estimated 850 million barrels of oil in place in this sand interval, the company said.

Viscous oil, thick oil that is difficult to tease from underground reservoir rock, is found in relatively shallow sands referred to as either the West Sak or Schrader Bluff formation above several of the central North Slope oil fields. Production of the viscous oil requires long, high-tech horizontal wells, and the use of sophisticated enhanced oil recovery techniques.

ConocoPhillips has also asked AOGCC to allow the expansion of a project that uses an enhanced oil recovery technique called viscosity reducing water alternating gas, or VRWAG, in the West Sak oil pool. The company says that the use of this technique can increase oil recovery beyond what is possible using waterflood, the base technique used to push oil into production wells.

In February ConocoPhillips said that it had applied for permits for a new viscous oil development in northeast West Sak, to the north of the core West Sak area where Kuparuk River unit viscous oil production currently takes place.

—Alan Bailey