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Anadarko files plans for Dolly Varden, Arctic Char prospects in Foothills Company looking at using old Aufeis drill site and gravel airstrip for staging of rig, allowing earlier start to drilling at gas exploration projects Kristen Nelson PNA Editor-in-Chief
The hunt for natural gas in the Foothills is moving from seismic to the drill bit this winter. Anadarko Petroleum Corp. has filed applications for 2002-2007 winter gas exploration projects in the Foothills at its Dolly Varden and Arctic Char prospects some 60-70 miles south of Deadhorse and 10-20 miles west of the Dalton Highway.
The company is looking at five drilling locations — all of which could be drilled at some point in the five-year program.
Anadarko said this is a gas exploration program and told the state it does not expect to find oil.
Anadarko has told the state it does not believe these sites are in the coastal zone and has asked for an exemption from Alaska Coastal Management Program consistency review.
Anadarko noted that Dolly Varden and Arctic Char are more than 60 miles inland from the North Slope Borough coastal zone, 10-20 miles from the coastal zone corridor of the Sagavanirktok River and more than 20 miles from the coastal zone corridor of the Itkillik River.
Anadarko’s Whiskey Gulch prospect in section 30 township 8 north range 9 east, Umiat Meridian, and 22-T9N-R9E, UM, did not require ACMP review.
A single well is expected to be drilled this winter season at one of the two prospects. Staging allows earlier drilling Anadarko has developed five different exploration scenarios for the prospects, based on different modes of support, transportation of the drill rig, available infrastructure and staging considerations.
In each instance, the drill rig (Nabors 14E) begins in Deadhorse, but “in subsequent years,” Anadarko said, “the drill rig may be moved back to Deadhorse, staged in the field at the old Aufeis drill site (or possibly the Itkillik or East Kuparuk airstrip) or even staged along the Dalton Highway.”
If the drill rig is staged at Aufeis, drilling could begin in the early winter. The rig could also be moved to the Dalton Highway for off-season storage.
Anadarko is also looking at adding logistics support from Hercules aircraft to move rig components and supplies, as well as the alternative of moving the rig back to Deadhorse or the Dalton Highway, with no staging at Aufeis at all.
The Aufeis site — an abandoned well site with a gravel airstrip — is in section 25 of township 2 south, range 10 east, Umiat Meridian.
Anadarko listed one potential Arctic Char drilling prospect and four potential Dolly Varden prospects.
Arctic Char No. 1 is on state oil and gas lease ADL 389763 in T2S-R10E, UM, as is one of the proposed Dolly Varden sites (No. 2). The second proposed Dolly Varden site, No. 4, is on ADL 389764 in T2S-R11E, UM.
Dolly Varden No. 5 and No. 7 are on Arctic Slope Regional Corp. selected lands in T2S-R11E, UM, and T2S-R12E, UM. Anadarko said the ASRC sites would not be drilled until those lands have been conveyed.
All potential drill sites are in the Toolik River watershed. All scenarios require ice roads Access to each site will be by ice road, airstrip and Rolligon under all scenarios, Anadarko said. If the rig is staged at Aufeis a tundra move of the rig would be required in late summer or early fall. The company said portions of the rig might be flown to the site if a Herc-sized airstrip is put in place.
If the rig is staged at Aufeis, subsequent activities would involve ice roads, tundra travel and small aircraft support.
Ice roads will be built to the Dalton Highway during the drilling season and logistical support will use the Dalton Highway corridor and ice road, rather than relying on tundra travel and aircraft.
There are two alternate routes for the ice road off the Dalton Highway: a northern route originating approximately nine miles north of Pump Station No. 1 and running generally southwest for 42 miles to the project — as many as 54 miles of ice road to Aufeis; and a southern route originating either near the Sagwon airstrip along the Dalton Highway or at a point approximately eight miles north of Happy Valley, running generally west for 13 miles to Dolly Varden site No. 7 and eventually reaching Aufeis at mile 36.
Anadarko estimates that the maximum annual total for ice roads would be 65 miles on the northern route and 40 miles on the southern route.
Each route requires crossing the Toolik River to reach all of the drill sites. Anadarko said the Toolik is the largest river in the area; crossings of approximately 25 permanent small streams would also be required. Fifty days to build ice roads The ice roads will be 35 feet wide and six inches thick and the pads 600 feet by 600 feet. Each operating crew can construct approximately 0.75 mile of ice road per day and Anadarko told the state it proposes to use two crews and build up to 54 miles in about 50 days. Each mile of road requires about 1 million gallons of fresh water and each ice pad requires about 4 million gallons of water.
Anadarko said the distance to haul water will be long as some 80 percent of the available water is from one deep lake near the origin of the southern route by the Dalton Highway. Staging prep in September For the 2002-03 winter season, Anadarko said that if it uses the Aufeis staging area it would begin to prepare the site and mobilize on Sept. 1. Nabors rig 14E would be moved to the site by Rolligon beginning Sept. 21. A camp will accommodate up to 60.
Ice crews and water trucks would be mobilized to Aufeis by Rolligon beginning Nov. 1 to build the ice pad and airstrip and to build an ice road from Aufeis to the pad if needed.
If a strip is needed for a Hercules aircraft, that work would begin Nov. 16.
The rig would be moved to the drill site beginning Nov. 20.
Ice road construction would begin Dec. 6, the well would be spud Dec. 18 — the beginning of a 60-day drilling program. Well testing would begin Feb. 16 and rig down and moving of the rig to Aufeis or the Dalton Highway would begin March 18, with remedial work at the pad scheduled for April 12 and the operation completed, inspected and closed May 1.
Anadarko said it plans to plug and abandon the well, but it might be temporarily suspended if well evaluations cannot be completed prior to closure of tundra travel. Vertical seismic profiles may be acquired using up to three vibroseis trucks.
Two wells possible in subsequent years
The 2002-03 season is 242 days of work, but subsequent seasons would be 181 days if the rig is stored at Aufeis. One well is planned for 2002-03. Anadarko said that if the rig is stored at Aufeis, it may be possible to drill and test two wells in subsequent seasons.
If the rig is stored at the Dalton Highway or in Deadhorse a single well is likely in subsequent years.
Anadarko plans to submit applications for the Snow Goose project later this summer, as well as for wells for a gas hydrates research project. New technology Anadarko has also told the state it is looking at new drilling pad technology, a “patent pending” drilling design concept called a “tundra table,” an onshore drilling platform that doesn’t require gravel and would replace ice pads for winter exploration.
The platform, 500 feet by 500 feet, looks like an offshore platform and sits 12 feet off the ice. Pilings go into the ground and the platform fits onto the pilings, which are temperature regulated.
And this new drilling pad would be Rolligon based — no ice roads required, Anadarko said.
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