ConocoPhillips Alaska Inc. is targeting two prospects with its Putu exploration program.
The proposed directional Putu No. 2 well and vertical Putu No. 2A sidetrack will penetrate and evaluate two separate prospects, the local subsidiary of the global independent exploration and production company revealed in recent permitting filings.
The Putu No. 2 well will “evaluate the reservoir and hydrocarbon potential of the western prospect, provide control for picking core point for the Putu No. 2A well, if needed, and increase the accuracy of the velocity model for depth prediction,” the company wrote in an amended plan of development submitted to the state Division of Oil and Gas on Nov. 20. The company intends to drill the Putu No. 2A sidetrack to evaluate “the eastern prospect,” although information gained from the first well could prove sufficient.
The descriptions “western” and “eastern,” and the fact that the well is directional while the sidetrack is vertical, suggest a simple geography difference between the two prospects. Depths will reveal whether the wells are also targeting different formations.
The Putu program is an effort to expand development of the Colville River unit to the south, into a region that has intrigued ConocoPhillips and others for more than a decade.
A well and sidetracks drilled in the area in 2008 by Brooks Range Petroleum Corp. encountered hydrocarbons in several horizons, including in the Nanushuk formation.
ConocoPhillips originally intended the drill the Putu well last winter but said that it delayed the project to accommodate the concerns of local communities. The state required the company to drill at least one well this year to keep from losing the acreage.
After months of regulatory deliberations, the Department of Natural Resources approved an expansion of the unit in August 2017 to include the Putu acreage to the south. The approval required ConocoPhillips to drill one well in 2018 and one by 2020. The two-well program planned for this winter, if completed, would satisfy both commitments.
The Alaska Division of Oil and Gas is taking comment on the plan through Dec. 22.
AccommodationsGiven the proximity of the program to Nuiqsut, ConocoPhillips is incorporating some unusual features into what would otherwise be a fairly typical exploration program.
The company plans to drill the well and the sidetrack this coming winter from an ice pad to be constructed on an island between the main and Nechelik Channel in the Colville River Delta, some 2.8 miles west of Nuiqsut. The 640,000-square-foot ice pad (800 feet by 800 feet) is planned for on ADL 390674 and will include a temporary camp capable of housing approximately 65 people. The company plans to access the site by ice road.
ConocoPhillips plans to power its drilling operations using six Tier 4 diesel generators located on a 40,000-square-foot ice pad (200 feet by 200 feet) located one mile north of the drilling site and connected back to the rig using a 13.8-kilovolt transmission line encased in a 25-foot wide and 25-inch thick block of ice. The offsite generator and associated transmission line will also power the work camp, which will have a back-up diesel generator in case of power outages, equipment malfunction or other emergencies.
The ice-encapsulated power line will be distinct and separate from the ice road used to accommodate truck traffic to the drilling pad. The power line will be housed in a special ice-encapsulated casing where it crosses beneath the existing Alpine Resupply Ice Road.
The atypical system is intended to alleviate the impacts of the drilling program on nearby Nuiqsut, according to ConocoPhillips. The company said it is also developing a special “lighting plan” for the project to reduce the amount of lighting visible from the village.
The exploration program is planned for surface land owned by the Kuukpik Corp. The two parties have entered a surface use agreement, according to ConocoPhillips. The relevant subsurface land is jointly owned by the state and Arctic Slope Regional Corp.
ConocoPhillips expects drilling operations to run from mid-January to mid-March 2018, with testing in the first half of April and demobilization by the end of the month. The company warned that the unpredictability of tundra openings could alter the schedule.