Anadarko to drill two NPR-A wells south of Moose’s Tooth this winter; Brooks Range foothills drilling possible in 2002-2003

Company says 2001-2002 drilling may be south of Kuparuk if permitting or weather delays make crossing Colville River a problem

Kay Cashman

PNA Publisher

Anadarko Petroleum Corp. officials in Alaska told PNA in late August that the oil company has filed permits for two exploration wells in the National Petroleum Reserve-Alaska for drilling in the 2001-2002 drilling season. (See map on opposite page.)

The NPR-A well locations are:

Altamura No. 1, section 30, township 9N, range 2E, Umiat Meridian

Altamura No. 2, section 19, township 9N, range 2E, Umiat Meridian

The Texas-based independent said the wells will be drilled on lease AA081736, which is 100 percent owned by Anadarko.

Altamura No. 2 is 3 miles south of the Rendezvous 2 well that Phillips Alaska Inc. drilled and suspended last season: “We obviously believe the trend goes down into this area. We’re seeing something they didn’t see,” Anadarko said.

Contingency wells at Whiskey Gulch

Anadarko has Nabors Rig 14E,” the last of this type of rig still in a Herc-able configuration on the North Slope,” under a two-year contract. “We’ve been paying for it since June, so we want to make sure we can drill,” Anadarko said.

The Whiskey Gulch oil prospect, south of Kuparuk and due east of Meltwater, is close to infrastructure. The company said it could run an “ice road south from Kuparuk or east from Meltwater … or from Tarn.”

Whiskey Gulch, currently 100 percent owned by Anadarko, is an old prospect, which has been drilled “in and around” by ARCO. Anadarko is in the process of reviewing 3-D seismic that was shot over the area this last winter.

Foothills drilling in 2002-2003

The company elected not to drill in the foothills this year because of logistics challenges and water availability problems (see sidebar to this story).

Anadarko and its partner AEC Oil & Gas (USA) Inc., the U.S. subsidiary of Alberta Energy Co. Ltd., were high bidders on 36 of 43 bid tracts covering about 207,000 acres in the first North Slope Foothills areawide oil and gas lease sale on May 9.

Anadarko entered into a 3 million acre exploration deal with Arctic Slope Regional Corp. in the foothills in1998. AEC and BP Exploration (Alaska) Inc. later acquired a one-third interest in the exploration venture.

Anadarko is the operator on the foothills properties.

Dolly Varden first

Other Anadarko prospects, including Pingo, south of Badami, are still being evaluated and will be deferred, the company said, “for a year or two.” The company’s coastal plain prospects are oil and possibly gas, while the foothills targets are gas.

Anadarko has identified eight well sites in its Dolly Varden prospect southwest of the trans-Alaska oil pipeline’s Pump Station 2. The sites are “anywhere from 15 to 25 miles from the Haul Road,” the company said. The exploration team would depart the Haul Road somewhere near Happy Valley.

Half the well sites are on Arctic Slope Regional Corp. land and half are on state leases.”

There are several old exploration wells in the area that Anadarko said “kind of bracket the prospect,” which “runs linear in an east-west connection.”

The old wells include ARCO’s 1960s Susie Unit 1, which is 10 or 15 miles to the north, and Amoco’s 1974 Aufeis unit well, which is approximately five miles south of two of the proposed drill sites.

Anadarko shot a lot of seismic throughout the proposed drilling area this past winter: “We did a lot of 2-D seismic. … Most of the 2-D was west of the Haul Road. We didn’t complete all of the 2-D seismic that was planned.

Anadarko had PGS Onshore shoot 3-D seismic over its K-Square prospect near Kavik (due south of Point Thomson) in the foothills and over its Pingo prospect south of Badami.

“Phillips had a Western Geco crew in the area last winter and they did some 3-D near Whiskey Gulch for us. We’ll probably be doing more 2-D and 3-D this winter,” Anadarko said.

The company said this past winter it had geophysical crews “working from the ANWR border on the east to NPR-A border on the west. … almost down to Anaktuvuk Pass. We’re looking at that whole area … it is still a little early to drill in the foothills. We want a little more data. We didn’t get quite as much data as planned this year.”

Editor’s note: During the past two winter drilling seasons, six wells and a sidetrack were drilled in the NPR-A by Phillips with Anadarko as a 22 percent partner. Five wells and the sidetrack, which targeted the Alpine producing horizon, all encountered oil or gas and condensate. These wells are Spark No. 1 and Spark No. 1A, Moose’s Tooth C, Lookout No. 1, Rendezvous A and Rendezvous No. 2. A sixth well, targeting a different interval, was a dry hole.

Limited water supplies, hilly terrain challenge explorers in foothills

Petroleum News Alaska Staff

But logistical challenges forced the company to reconsider its initial exploration targets.

In addition to being far from existing infrastructure, the foothills are also farther from the substantial sources of water needed to build the ice roads and pads necessary for exploration.

“Ice roads and pads require a lot of water, and you also need a healthy supply of water for drilling muds. In the foothills finding good sources of water is a challenge,” Anadarko said. “The lakes are fewer and farther between.”

And then there’s the problem of driving on ice roads in the winter. On the coastal plain of the North Slope, the roads are flat. In the foothills, they are often hilly. Ice and hills can make for dangerous driving conditions.

“You can’t climb a steep grade when it’s made of ice…. If you get much above a 6 or 8 percent slope, you have problems moving a drilling rig,” Anadarko said.

Anadarko is in the process of looking for routes to its well sites that “would avoid some of the hurdles.”

How did the pre-1980 explorers navigate in the foothills?

“Everything was done off of gravel pads and gravel airstrips,” Anadarko said. “They Herc’d rigs in. It was a two season project. You’d go in one season to construct roads and pads; then come back the next year.”