Repsol plans extensive North Slope exploration

The Spanish oil and gas company plans to run five rigs this winter to drill as many as 15 wells and sidetracks from five ice pads to onshore and offshore central North Slope targets.

The five proposed drilling locations would run down the fairway between the Colville River unit to the west and the Oooguruk and Kuparuk River units to the east.

Repsol is planning a vertical well and as many as two sidetracks at each location.

Although it has held offshore leases for years, Repsol picked up 494,211 state acres this past March in a deal with 70 & 148 LLC, the North Slope subsidiary of Denver-based Armstrong Oil and Gas, and GMT Exploration Co. LLC, also based out of Denver.

Repsol acquired a 70 percent interest in 157 leases for $768 million. The vast majority of that money will be directed toward exploration, according to Petroleum News sources.

Repsol is already preparing for that drilling program.

The company conducted fieldwork this summer to define the route and location of the ice roads and pads it plans to build this winter and to identify water sources for that construction. The company will begin monitoring soil temperatures along the route this month, September, using thermistor strings, and pre-pack the roads in November and December.

Once temperatures permit in December and January, Repsol plans to build 30 miles of onshore ice roads and 30 miles of offshore ice roads.

In total, the company will build seven ice pads, two near Drill Sites 3S and 2P in the Kuparuk River unit for staging, and five -- four onshore and one offshore -- for its 15-well drilling campaign. Repsol plans to drill "at least" one vertical well and, "time permitting," up to two sidetracks from each pad.

The four onshore drilling pads will be about 500 feet by 500 feet, but could be expanded to 600 feet by 600 feet "if needed." The offshore drilling pad will be larger, with additional design elements to accommodate the harsh conditions of Arctic coastal waters.

The company expects to begin demobilization and cleanup in April or May.