While much of rural Alaska copes with the high cost of diesel fuel, the city of Barrow is powered by three nearby natural gas fields: South Barrow, East Barrow and Walakpa.
That gas has drastically changed life in the North Slope Borough’s largest city.
“I remember when we first got it my father ordered a brand new stove. The stoves we had were meant for diesel. He bought a gas range and a new heating stove. It was wonderful I didn’t have to cut wood anymore or get sacks of coal from next door at the store,” state Rep. Ben Nageak told Petroleum News in March 2014. “We kept warm 24 hours a day. It’s a long ways from when I grew up. The heat would go out and we would be cold.”
Through July 2014, the three fields had produced nearly 60 billion cubic feet of natural gas cumulatively, according to figures from the Alaska Oil and Gas Conservation Commission. The fields were producing at a summer rate of 2.8 million cubic feet per day in July 2014 and a winter rate of 5.4 million cubic feet per day in January 2014.
South Barrow
The U.S. Navy discovered South Barrow with the 2,505-foot South Barrow No. 2 well in 1948, during its initial wave of National Petroleum Reserve-Alaska exploration.
Production began the following year. But development drilling continued for decades, with 13 wells drilled through 1987 and one subsequently deepened, according to the AOGCC. Production peaked at some 3.5 million cubic feet per day in November 1981.
Cumulatively, the field produced some 23.7 billion cubic feet of gas through July 2014, according to the AOGCC. Originally, the field was expected to produce some 32 bcf.
South Barrow is used to meet demand during peak winter months and suspended in summer. The field produced some 172 thousand cubic feet per day in January 2014.
East Barrow
The U.S. Geological Survey discovered the East Barrow field with the South Barrow No. 12 well in 1974, during the second wave of NPR-A exploration. Production began in December 1981, but drilling continued through 1990, with eight wells altogether.
East Barrow production initially peaked at some 2.75 mmcf per day in early 1984.
The field produced nearly 380 thousand cubic feet per day in January 2014 and nearly 200 thousand cubic feet per day in July 2014. Cumulatively, the field had produced nearly 9 bcf through July 2014, surpassing the original estimate of 6.2 bcf of gas in place.
The city of Barrow attributes the productivity of East Barrow beyond original field estimates to methane hydrates, which are thought to exist at the field. Methane hydrates are molecules of natural gas trapped inside cages of ice. The gas can be released through pressure changes. Drops in pressure occur naturally during the aging process of a field.
Walakpa
The reservoirs for South Barrow and East Barrow are in a stratigraphic setting similar to the Alpine field some 135 miles to the east. The third field supplying Barrow, Walakpa, is in the Pebble Shale unit, a major North Slope petroleum source rock.
Today, Walakpa produces the majority of the gas delivered to Barrow.
Working under a Navy contract, Husky Oil discovered Walakpa with the 3,666-foot Walakpa No. 1 well in the 1980s. Production began in the early 1990s. The field has peaked above 5 million cubic feet per day numerous times, including in early 2013.
Cumulatively, the Walakpa field had produced some 26.3 bcf through July 2014, according to the AOGCC. The field is thought to hold some 250 bcf. The field produced nearly 5 mmcf per day in January 2014 and nearly 2.9 mmcf per day in July 2014.
Rejuvenation campaign
Realizing it needed to improve the deliverability of its three fields to meet a forecasted growth in demand, the city of Barrow launched a rejuvenation campaign in recent years.
A pair of voter-approved bond sales allowed the city to launch a $92 million program in 2011. The city drilled the Savik 1 and 2 wells at East Barrow and the Walakpa 11, 12, and 13 wells at Walakpa - the first horizontal drilling campaign at the fields. The city also plugged and abandoned eight depleted wells and upgraded infrastructure.
By improving deliverability, the program gave Barrow the ability to meet its energy needs even during extenuating circumstances such as cold snaps or maintenance; previously, the city had to rely on diesel fuel to meet its energy needs during those times.
