Marathon: 50 years in Alaska - Glacier Rig purpose-built for Marathon’s peninsula drilling

Kristen Nelson

Petroleum News Editor-in-Chief

Marathon’s purpose-built mobile drilling rig arrived in Alaska in early 2000. “It basically sits on a huge drip plan to protect the environment from spills,” John Barnes, Marathon’s Alaska business unit manager, said Aug. 13.

Glacier Drilling No. 1 is a truck-mounted rig owned by a Marathon subsidiary and operated for Marathon by Inlet Drilling, the company’s Alaska business unit manager, Barnes said.

Barnes described the rig in more detail in a March 2001 talk to the Alaska Support Industry Alliance.

He said a separate substructure, built specifically for the rig, is also mobile, as are two pit and pump trailers, including a totally self-contained mud system.

The rig spud its first well April 7, 2000, and by early 2001 had “drilled to nearly 12,000 feet; it’s also drilled a 2,600-foot horizontal at nearly 9,000 feet,” he said.

Barnes said the rig has “basically met or beat every drilling curve that we’ve compared it to in the Cook Inlet — and we’re looking at the bigger rigs that have been used historically.” The rig was designed for work close to neighborhoods, the situation Marathon faces at its Cannery Loop field. Barnes said it was designed with a small footprint, total containment of fluids and hospital-quiet mufflers.”

It’s not usual for an operator in North America to own a rig, Barnes said, but the company anticipated a multi-year drilling program, knew there would be a need for the rig in the Cook Inlet area and wanted to be sure a rig would be available when Marathon needed it. A rig that was the right size for its projects and lower costs were also considerations.

“If you can lower your cost on your wells that you can drill for a fixed capital budget, you can drill more wells,” Barnes told the Alliance.

Marathon said that by August 2004, the Glacier drilling rig had drilled more than 30 wells and more than 250,000 feet of hole.