Dewline unit expanded; another well required

The State of Alaska has expanded the Dewline unit and required operator UltraStar Exploration to add another well to its plans for the acreage north of Prudhoe Bay.

Under the new unit terms, UltraStar must now drill the N. Dewline No. 1 well by May 31, 2013, and the N. Dewline No. 2 well by May 31, 2014, or risk losing the unit.

The Division of Oil and Gas made its ruling on March 15.

The expansion adds ADL 390608, an offshore lease acquired in an October 2004 lease sale, to the unit. The expansion brings the size of the four-lease unit to some 4,533 acres.

UltraStar drilled the Dewline No. 1 well at the unit in April 2009 and managing member Jim Weeks previously told Petroleum News that it plans to drill a follow up next year.

Weeks described the N. Dewline No. 1 as a 14,000- to 15,000-foot directional well to an offshore target from an onshore pad, with a 6,000-foot displacement. The new expansion lease is slightly more than 6,000 feet from the shoreline in the Dewline unit.

The main target for the well is in the Ivishak sandstone, but the well could also be used to explore potential targets in the Sag River formation and the Kuparuk formation. Although exploration drilling in the region north of Prudhoe Bay dates back to the 1960s, commercial production eludes the area, despite its proximity to significant infrastructure.

—Eric Lidji