Written by Tim Bradner
Australian independent 88 Energy has made an apparent oil discovery with its Merlin-1 exploration well in the southeast National Petroleum Reserve-Alaska, or NPR-A, and more test results are expected in the next few days, the company said March 31.
An independent geologist said the find could be significant because it would show that an oil-bearing regional geologic formation, where discoveries have previously been made, is larger than thought.
Based on geologic modeling and seismic data, 88 Energy estimates a potential oil resource of 650 million barrels at Merlin-1.
The NPR-A is a 23-million-acre federal reserve west of Prudhoe Bay and other large producing fields on the North Slope.
88 Energy found oil at multiple intervals in Merlin-1 but a significant oil column was detected in a target zone in the Nanushuk, a geologic formation extending across the eastern NPR-A where other companies have made discoveries.
Two of those discoveries are now in development planning, ConocoPhillips’ “Willow” discovery north of the Merlin well and Pikka, a find on state lands east of the NPR-A that is being developed by New Guinea-based Oil Search, are both in the Nanushuk and are targeted for production expected by 2026.
ConocoPhillips and Oil Search say their discoveries are now estimated to hold several hundred million barrels of recoverable oil. ConocoPhillips has also made a discovery at “West Willow,” a few miles west of Willow, and an apparent find at “Harpoon,” a few miles to the southwest.
88 Energy said wireline testing is now underway at Merlin 1 to assess the mobility of the oil, or its ability to flow through rocks. But Richard Garrard, an independent Alaska exploration geologist, said data released by 88 Energy indicates the presence of light oil. “That is an encouraging sign,” Garrard said.
88 Energy also said the target zone, an oil column, in the Nanushuk, appears thicker than that encountered at Willow by ConocoPhilllips. However, Garrard said not enough is known about this, such as whether there could be shales occurring with the oil-bearing sands. The current wireline tests will also confirm the porosity and permeability of the rock.
“Whist there is still work to do to determine a discovery, the results to date are encouraging,” 88 Energy’s managing director said in the company’s statement.
The company is also planning another test at a second, nearby prospect, Harrier 1, with the primary target also in the Nanushuk formation, as well as another geologic formation that has been productive in other exploration in the western North Slope. 88 Energy said its geologic modeling shows a potential for 450 million barrels of recoverable resources at Harrier.
In a related development, 88 Energy has also satisfied conditions to complete its acquisition of the Umiat field, a historic oil discovery made in 1945 by the US Navy that is adjacent to leases held where the Merlin well was drilled.
Eleven appraisal wells were drilled by the Navy and a private company, but Umiat was never commercially developed. 88 Energy cemented and plugged old wells to satisfy US Bureau of Land Management terms when it acquired two federal leases at Umiat covering 17,633 acres.