NSB moves ahead with Barrow gas wells

Original plan included DOE money for gas hydrate test; borough’s plan for new wells, plugging and abandonment, deferred to 2011-12

Kristen Nelson

Petroleum News

Barrow has been using natural gas from nearby fields on Alaska’s North Slope since production from the South Barrow gas field began in 1949. Now, the North Slope Borough, operator of the gas fields, is preparing to drill the first new wells there in almost two decades. The fields were discovered when the U.S. Navy was searching for oil in what was then Naval Petroleum Reserve 4, later renamed the National Petroleum Reserve-Alaska and moved from naval jurisdiction to that of the Department of the Interior.

The East Barrow field began production in the 1980s and the Walakpa field began production in 1993. The last gas drilling program at the Barrow gas fields was in the early 1990s.

Barrow, the northernmost city in the United States, is on the western edge of the North Slope. It is the governmental center for the North Slope Borough and the most populous of the borough’s eight communities.

“New wells are needed to supply existing and future peak demands,” said a permitting plan of operations for the project prepared for the borough by Petrotechnical Resources of Alaska.

The plan said that based on current estimates of consumption rates and reserves the borough’s “overall gas reserves are considered adequate. However, as the community has grown over the years, increased peak demand for natural gas required that new wells be drilled,” and a number of wells in the fields are now depleted.

As many as six new wells will be drilled in the East Barrow and Walakpa fields; up to eight depleted wells will be plugged and abandoned at the South and East Barrow fields. Two of the depleted wells are being evaluated for use as a disposal well for liquid wastes from the project; the second candidate well would be a backup.

The original plan was to do this work in conjunction with gas hydrate research drilling supported by the U.S. Department of Energy, but when the department dropped out due to lack of funds, the gas hydrate portion of the project was dropped.

And, the borough told the Alaska Department of Natural Resources’ Division of Mining, Land and Water, in a May 14 letter, while the work was originally scheduled to begin this year, the withdrawal of federal money and mitigations required by the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service resulted in deferral of drilling until 2011-12.

Discovered in late 1940s

The fields are shallow.

The discovery well for the South Barrow gas pool, the S. Barrow No. 2, was drilled by the U.S. Navy and is a vertical well with a depth of 2,505 feet.

Husky Oil drilled the Walakpa No. 1 discovery well in 1980. The vertical well had a depth of 3,666 feet. A stratigraphic table of the Walakpa development area shows the Walakpa sand at depths of between 2,020 and 2,550 feet.

Production from Walakpa began in the early 1990s after production wells were drilled at the field.

The Alaska Division of Oil and Gas Annual Report 2009, with forecasts updated through May 2010, estimates 5 billion cubic feet of reserves at East Barrow, 4 bcf at South Barrow and 25 bcf at Walakpa.

The South Barrow gas pool is the closest to Barrow, just to the east of town; the East Barrow pool is southeast of the South Barrow pool, while the Walakpa field is south of Barrow.

The permitting plan of operations said the borough consulted with the Bureau of Land Management and determined that no BLM lands were affected by any of the proposed work. The borough has rights to the East Barrow and Walakpa gas fields under the Barrow Gas Transfer Act of 1984 and the fields are not subject to leasing evaluated by the Northwest NPRA Leasing Environmental Impact Statement.

2011-12 schedule

Staging for the project will begin at facilities near West Dock at Prudhoe Bay July 1, 2011, with barging to Barrow from West Dock, Nikiski and Seattle beginning July 12, or as early as ice conditions allow. The borough said field work would begin based on the U.S. Fish and Wildlife Service 2011 summer nesting survey. If eider nesting is successful, field work would begin Sept. 1, after eider nesting is complete. If eider nesting is not successful, field work could begin with arrival of the first barge.

Rig up is expected to begin at the East Barrow field Sept. 8, 2011, and conclude by Nov. 6.

An ice road will be required to the Walakpa gas field and construction will begin as weather permits.

Rig up at Walakpa is expected to begin Dec. 28, 2011, or as weather permits, and conclude April 15, 2012, or as weather permits.

Equipment and wastes to be hauled from Barrow will be in secure storage until barging is completed in the 2012 barge season. Barging from Barrow is expected to begin July 12, 2012, and end Sept. 1, 2012, as ice conditions and whaling allow.

Small footprint rig

The permit plan of operations says the rig will be a light, truckable, rig such as Kuukpik No. 5, which is currently stacked in Kenai in Southcentral Alaska, and would be barged to the North Slope from Nikiski.

No gravel placement on tundra is proposed for roads or pads. Small well houses on pilings will be installed upon successful completion of new wells along with gathering lines and electrical transmission lines on vertical support members.

Two new wells on an existing gravel pad are planned at the East Barrow pool; four depleted wells will be plugged and abandoned. One of the depleted wells will require an ice or snow trail with a small ice work surface; others are on gravel.

Four depleted wells at the South Barrow gas pool will be plugged and abandoned. Two are on an existing road system and two will require temporary ice trails and small ice work surfaces at the wells.

A 27-mile ice-snow road will be required for the work at the Walakpa field, along with two ice staging pads and two production well ice drill pads.

Up to four production wells will be drilled and completed at two locations at Walakpa and approximately 350 feet of new VSM-mounted pipeline segments will be required to connect the new wells to gathering lines.

Rig crews will be housed in self-contained rig camps at the well site while working at East Barrow and Walakpa. While commercial housing in Barrow may be provided, the permit plan of operations said “a rig camp on site is preferred to provide greater efficiency and safety.”

Ice road construction crews will work from self-contained camps convenient to road construction and drilling pad locations.