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Work at ARCO Alaska’s Alpine field now 80 percent complete Horizontal directional drilling under Colville complete, pipelines installed; site work ready for sealift; development drilling under way
Compiled by PNA Staff
Work at ARCO Alaska Inc.’s North Slope Alpine field is nearly 80 percent complete, the company said in late June.
At the peak of the North Slope construction season, more than 950 craft people were on the slope — in addition to the Alpine team. In all, ARCO said, more than 1,400 people worked on the Alpine project this winter in Nikiski, Anchorage, Fairbanks and on the North Slope.
Horizontal directional drilling under the Colville River was completed this winter. The Alpine pipelines were also completed, linking the field to Kuparuk. Seven hundred and fifty thousand cubic yards of gravel were mined, hauled and placed by Nuiqsut Constructors, a joint venture formed by Kuukpik Corp. and SKW Eskimos, a subsidiary of Arctic Slope Regional Corp. Nuiqsut Constructors did all of the civil work for Alpine, including opening the mine, hauling gravel and constructing the storage and production pads and the airstrip.
Site preparation was completed for sealift modules and transport and installation of 25 truckable modules at Alpine and Kuparuk.
Crews also completed the start-up of the 300-man Alpine camp and installed its critical support systems.
Development drilling under way Doyon rig 19 started a five-year development-drilling program at Alpine this winter. A crew of 65 includes equipment operators, mud plant personnel, mechanics, electricians, etc.
A 92-well program of both horizontal and vertical wells has been sanctioned, but final approval will be sought this summer for an expanded, all-horizontal development plan. About 20 wells will be on-line by field start up in mid-2000. Initial production is estimated at 40,000 barrels per day, ramping up to 80,000 barrels per day in 2001. The new drilling plan calls for wells with 3,000-foot horizontal sections 1,500 feet apart, up to 50 percent longer than the 2,000-foot horizontal sections previously approved and twice as close as the previous 3,000 feet apart, ARCO said. The new plan calls for more than 60 miles of reservoir penetrations.
The plan up for approval this summer also adds enhanced oil recovery at Alpine start up. The EOR will use miscible injectant generated in the field. The reservoir core area will be developed using water/alternating gas injection; the peripheral of the field will use water flood.
Logistics crucial Rig modules and camp were transported to Alpine on the Beaufort Sea ice road. Drilling supplies were transported over a tundra ice road.
With the ice roads now melted, Alpine is accessible only by plane.
More than 78 million pounds of field supplies and drilling freight were moved in 1,674 truck loads — enough materials and supplies, ARCO said, to keep Alpine operations moving until the ice road is built next winter. About half of those loads were drilling supplies.
Originally scheduled to take 75 days, moving the supplies only took 45 days because supplies were staged at E-pad in Kuparuk and were ready to move when the ice road was completed in February. Colville River crossing The horizontal directional drilling crossing of the Alpine pipelines under the Colville River was, ARCO said, the first permafrost application of HDD — a technique used widely in other areas of the world, but not previously used in the Arctic. The Alpine HDD river crossing includes two 8-inch pipelines, one 14-inch pipeline with 20-inch casing and one 12-inch pipeline with 18-inch casing. The lines include the crude oil pipeline a seawater pipeline, a sacrificial anode and a utility pipeline carrying fiber optics and diesel.New technique in pipelines One 8-inch pipe was placed under the river last year, and ARCO said the HDD team of HDI, Houston Contracting, M-I Swaco DSR and ARCO Alaska completed the work this year four weeks ahead of schedule.
The Alpine pipeline includes seven vertical loops — eliminating the need for valves and reducing spill potential. ARCO called the new system “a win-win on all fronts: lower capital, lower operating expense, no periodic testing and smaller volumes in the event of a spill.”
The vertical loops are elevated 20-25 feet and as oil flows through the pipeline, pressure pushes it through the vertical rise. In addition to reducing total potential spill volumes and the potential for a spill compared with conventional valve systems, ARCO said, the vertical loops also provide high ground clearance crossings of the pipeline system for caribou and subsistence hunting.
Editor’s Note: Information above on Alpine is taken from the June issue of ARCO Alaska’s Spark.
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