Work is under way at Umiat.
In preparation for a drilling campaign scheduled for January, Linc Energy Inc. recently began building a snow road to the North Slope oil field, the company said Nov. 12.
The 100-mile snow road will begin at the Dalton Highway, near Pump Station 2, and continue to Umiat, located on the boundary of the National Petroleum Reserve-Alaska.
Linc is currently pre-packing the road and expects the development to take 30 days.
With the road complete, Linc expects to begin mobilization in mid-December. The mobilization effort involves moving a camp, drilling rig and equipment to the field.
During the mobilization, Linc plans to build in-field ice roads and ice pads.
Between January and April, Linc plans to drill at least four wells at Umiat, starting with Umiat DS No. 1, a Class II disposal well the company plans to spud around Jan. 18.
Four-well program
Using the Kuukpik No. 5 rig, Linc would move uphill, to the northwest, to drill Umiat No. 16, a vertical well into the Lower Grandstand. The program calls for collecting four 60-foot core samples from the formation and flow testing the well after completion.
From there, Linc plans to skid the rig approximately 10 feet to drill Umiat No. 16H, a horizontal well into the same interval. The side-by-side test is “important for assessing the performance of the horizontal production well in contrast to the vertical producer.”
While government expeditions drilled 12 wells at Umiat between 1946 and 1979, the current program would be the first to test horizontal drilling techniques at the field.
After drilling the side-by-side wells, Linc plans to move the rig to the east to drill Umiat No. 23, targeting natural gas in the deeper horizons below the Lower Grandstand.
The natural gas would be used for reservoir maintenance, according to Linc. Specifically, the company plans to inject cold gas into the Upper and Lower Grandstand to maintain reservoir pressure for production, a solution also proposed by previous lessees at Umiat.
Because at least part of its oil horizons are embedded in shallow permafrost, the Umiat field creates challenges for secondary recovery and pressure maintenance operations, Renaissance Umiat LLC explained in a January 2010 article in Oil & Gas Journal.
Aiming to figure out why early Umiat wells failed to produce as expected, a 1960 U.S. Bureau of Mines study found that warm drilling mud might have thawed the permafrost, allowing water into the reservoir sands. When this water inevitably froze, it plugged the formation. To combat this problem, Renaissance and others had proposed cold gas injections as a way to maintain reservoir temperature and therefore improve permeability.
After targeting and potentially producing natural gas from the well Linc plans to plug Umiat No. 23 back to the oil sands in the Lower Grandstand for an additional flow test.
In addition to those four wells, Linc is permitting two alternate locations — Umiat No. 18 and Umiat No. 19 — and said “one or both” could be drilled this winter, “if time allows.”
Previously, Linc outlined a five-well program for Umiat this winter, including a disposal well, two shallow vertical wells, one deep vertical well and one deep horizontal well.
Earlier this fall, Linc staked seven potential well locations with the U.S. Bureau of Land Management, the six previously mentioned wells and an Umiat No. 23H horizontal well.
This summer, Linc outlined an “aggressive timeline” to bring Umiat online within five to seven years. The company estimates peak production could be 50,000 barrels per day.
—Eric Lidji
