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Undulating horizontals planned for Nanuq Conoco pegs recovery at 33 million to 98 million barrels from combined Nanuq, Kuparuk reservoirs at Alpine satellite field Kristen Nelson Petroleum News Editor-in-Chief
ConocoPhillips Alaska expects to begin production from both the Nanuq and Fiord Alpine satellites in November 2006, company officials told the Alaska Oil and Gas Conservation Commission at an Oct. 4 hearing for Nanuq pool rules.
As at Alpine, all wells at Nanuq will be horizontal, said Jordan Wiess, development manager for the Nanuq and Fiord satellites, and the pool rules requested, he said, are similar to those for Alpine and Tarn.
The Nanuq satellite, which will produce from both the Nanuq and Kuparuk reservoirs, has some 84 million to 169 million barrels of oil in place at Nanuq and some 21 million to 36 million barrels in the deeper Nanuq-Kuparuk formation, petroleum engineer Jim Bennett said in describing the reservoirs. Sixteen undulating horizontal wells are planned to the Nanuq reservoir, seven producers and nine injectors, with an average horizontal length of 6,000 feet; three horizontal wells, two producers and one injector, are planned to the Kuparuk reservoir, also averaging 6,000 feet of horizontal length.
ConocoPhillips has a 78 percent working interest at the Colville River unit and is the operator; Anadarko Petroleum holds the remaining 22 percent interest. Arctic Slope Regional Corp. and the State of Alaska are both royalty owners. Miscible WAG Both reservoirs will be produced with miscible waterflood alternating gas, Wiess said.
Primary recovery is estimated at 7-12 percent for Nanuq and 12-17 percent for Kuparuk. Waterflood recovery is estimated at 10-15 percent at Nanuq and 25-37 percent at Kuparuk. Enhanced recovery, miscible water alternating gas, is estimated at 9-14 percent at Nanuq and 17-25 percent at Kuparuk.
The total recovery is estimated at 26-41 percent for Nanuq, 22 million to 69 million barrels, and 54-79 percent at Kuparuk, 11 million to 28 million barrels, for an estimated combined ultimate recovery range of 33 million to 98 million barrels, Bennett said.
The combined peak production rate for CD-4 is estimated at 10,000 to 15,000 barrels per day.
Wiess said gravel is in place for both the Nanuq road and pad, CD-4, and vertical support members and piles are in place on the pad for facility installation this winter.
The Nanuq oil pool correlates to Tarn and Meltwater at Kuparuk, while the deeper Nanuq-Kuparuk interval correlates to the Kuparuk C sands, geologist Steve Moothart told the commission. The Nanuq oil pool was identified in the Nanuk No. 2 well between 7,043 and 7,223 feet measured depth; the Nanuq-Kuparuk oil pool corresponds to the interval from the Nanuk No. 2 well between the depths of 7,956 and 7,972 feet. ConocoPhillips presented detailed geologic data in a closed-door session. Asked by commission Chairman John Norman to characterize the confidential data, Moothart said it included more in-depth interpretations of the depositional setting based on proprietary seismic data. Undulating horizontals A five-day production test was run on the vertical Nanuk No. 2 exploration well, Bennett said. Oil production from both the Nanuq and Kuparuk averaged 1,750 bpd of oil, 1,000 bpd of water and 1.2 million cubic feet per day of natural gas. The Nanuq oil had an API gravity of 39; Kuparuk had a gravity of 40.
Bennett said the 6,000-foot horizontal sections planned for the wells would undulate in the Nanuq. Drilling engineer Brian Noel said the undulating horizontal wells would make up to six passes through the Nanuq reservoir. Slotted liners will be used in both the Nanuq and Kuparuk, and Noel said the first well in the Nanuq will be tested to evaluate the completion.
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