ConocoPhillips Alaska will begin producing oil from an Alpine satellite field, Nanuq, in the fourth quarter of 2006.
The company told the Alaska Oil and Gas Conservation Commission in a pool rules application that the field will produce from both the Nanuq and Kuparuk formations; the commission has scheduled a hearing for Oct. 4.
Chris Alonzo, ConocoPhillips Alaska’s western North Slope development supervisor, said in the company’s Aug. 11 application that construction of infrastructure to support Nanuq production, which will be from new Drill Site CD4, started last winter. First production from the Nanuq facilities is expected in the fourth quarter of 2006, Alonzo said.
The shallower of the two oil pools, Nanuq, is in the Torok formation, and directly overlies a deeper Kuparuk River formation pool. ConocoPhillips said it will implement a miscible water alternating gas project for enhanced recovery in both oil pools when production begins.
The company said it will be applying to the State of Alaska and Arctic Slope Regional Corp. for the formation of Nanuq and Nanuq-Kuparuk participating areas later this year.
Development drilling is scheduled to begin at CD4 in October and is expected to end in November 2007.
Nanuq sandstone principal reservoir
The principal reservoir at Nanuq is the Nanuq sandstone, “an Albian submarine fan system,” with secondary production from the Nanuq-Kuparuk sandstone, ConocoPhillips told the commission.
Four discovery and appraisal wells (Nanuq No. 1, No. 2, No. 3 and No. 5) have been drilled at the field and two of the wells, Nanuq No. 3 and No. 5, will be used in the development. In addition to production tests from these wells, a horizontal well, the CD1-229, was completed from the Alpine CD1 pad and production tested for several weeks in 2001, the company said. Two merged 3-D seismic data sets, shot in 1996 and 2003, cover the area.
The Nanuq reservoir is a stratigraphic trap; there are no major faults. Original oil and original gas cap gas in place in the development area are estimated at 84 million to 169 million barrels of oil and zero to 40 billion cubic feet of natural gas.
The Nanuq-Kuparuk reservoir is also a stratigraphic trap, with one mapped fault at the northern edge of the reservoir which ConocoPhillips said is not expected to affect recovery. Original oil in place in the development area is estimated at 21 million to 36 million barrels.
Production tests of the Nanuq interval ranged from gravities of 39 degrees API to 42 degrees API; the Kuparuk interval tested at 40 degrees API. ConocoPhillips said geochemical analysis indicates oils from the Kuparuk and Nanuq reservoirs are closely related.
Horizontal development
Nineteen horizontal wells are planned for Nanuq CD4 development, 16 to the Nanuq reservoir (nine producers and seven injectors) and three wells to the Kuparuk reservoir (two producers and one injector). ConocoPhillips said well design at Nanuq will be similar to Alpine, where development drilling began in 1999 and where 97 horizontal wells had been completed as of June 1.
The Nanuq oil pool will be drilled with undulating horizontal wells of up to 7,000 feet; horizontal wells in the Kuparuk oil pool would be horizontal wells with lengths of 4,500 to 6,000 feet.
The Nanuq CD4 pad is some four miles south of the main Alpine facilities. A 3.8-mile gravel road will connect a 9.3-acre gravel pad at Nanuq with the main Alpine facilities. There will be produced oil, water injection, miscible injectant and gas lift pipelines from the Alpine production facility to Nanuq; powerlines will be suspended below the pipeline.
Nanuq is part of the Colville River unit and working interest ownership of the Nanuq leases is the same as leases at Alpine: 78 percent ConocoPhillips Alaska and 22 percent Anadarko Petroleum.
