Early data from the North Slope’s two winter exploration wells are encouraging, operators say.
88 Energy, whose subsidiary Emerald House drilled the Merlin 1 well in the National Petroleum Reserve-Alaska, said March 29 that “interpretation of logging while drilling data indicates multiple potentially hydrocarbon bearing zones” were encountered in the Nanushuk formation.
The company said March 31 that wireline logging is underway with preliminary results expected April 3-4.
Pantheon Resources, whose affiliate Great Bear Pantheon drilled the Talitha A well on state land this winter, said that it encountered five zones in the central North Slope well, “all of which are hydrocarbon bearing and warrant testing.”
Prior to drilling the company said Talitha A’s target was “the shallowest Shelf Margin Deltaic horizon as the primary objective” and would also “drill through a number of secondary objectives including: (i) the ‘Slope Fan System’, (ii) the ‘Basin Floor Fan’, and (iii) the ‘Kuparuk’ horizons.”
“Since the pressure exceeded our predrill estimates we are proceeding cautiously with all well bore and testing operations and will report results to shareholders once available,” Pantheon said.
Pantheon is currently testing “the deepest” of the horizons encountered in Talitha A, the Kuparuk, where it ran into “higher than expected reservoir pressure which is very good news.”
The company said that this “along with the exceptionally light oil we have collected as samples during circulating gives us optimism.”
Pantheon, however, said it cannot draw any definitive conclusions until testing operations have been completed in the Talitha unit well.
Prior to drilling Pantheon estimated the Talitha well would target approximately 1 billion barrels of recoverable oil across the multiple stacked (primary and secondary) objectives. An independent expert’s report was completed on the updip section of the Shelf Margin Deltaic, the primary target, and confirmed a prospective resource of 302 million barrels of recoverable oil, the company said.
About 500 feet thicker88 Energy said the Nanushuk formation was “encountered at ~600’ low to prognosis and is interpreted to be ~500’ thicker than that encountered in the wells drilled into the Willow oil field” analogue wells to the north of the company’s Peregrine project acreage.
“Encouragingly, the gamma log indicates the presence of more sand packages than those in the analogue wells and … the sand packages in Merlin 1 are generally cleaner in nature. … Oil shows were recorded over multiple intervals in the Nanushuk while drilling, including the primary targets,” 88 Energy reported.
Fluorescence “ranged from relatively weak to moderate ‘dry’ … with slow to moderate sometimes fast streaming cut when exposed to solvent. Mud gas peaks were also recorded and, although generally not of the same scale of the increase in total gas above background as that seen in the analogue wells, one of the prospective horizons in Merlin 1 did have substantially elevated total gas, similar to that in the analogue wells,” the company said.
Heavier gas components, “including C5, were observed over multiple intervals,” 88 Energy said. “Resistivity was elevated over these intervals and is encouraging, particularly in the context that the Nanushuk is considered a low resistivity play type.”
Fluorescence, the company said, was also “observed in the drilling mud (‘pops’) accompanied by a petroliferous odor over three of the target intervals. Significantly, one of these intervals is interpreted to be part of a potentially separate, sand package that is also present in the Harrier prospect,” which is also part of the Peregrine project.
Merlin 1 is targeting 645 million barrels of gross mean prospective resource. A second well, Harrier-1, expected to be drilled in winter 2022, is targeting gross mean prospective resource of 417 million barrels.
Umiat acquisition updateIn its March 31 update, 88 Energy announced that its acquisition conditions have all been satisfied for the Umiat oil field.
“The final condition related to the acquisition of the … oil field is now complete with cement work associated with plugging and abandoning of two historical wells at the field now executed,” the company said, noting “remedial site work will be finalized in the near-term.”
Umiat is an historic oil discovery made in 1945 in shallow Brookian (Nanushuk) sandstones, located immediately adjacent to the southern boundary of the Peregrine project.
The field is covered by two leases totaling 17,633 acres that are in a unit formed in September 2019 with an initial 10 year term.
“The current conditions of the unit stipulate a well commitment (exploration or appraisal) by Aug. 31, 2022,” 88 Energy said.
Eleven appraisal wells were drilled in the Umiat field by 1953, several of which were tested, the company reported: “Umiat 5 flowed 268 barrels per day on a 3-month test and Umiat 8 had a peak flow rate of 5.9 million cubic feet per day of natural gas during a 4-day test.”
Little work was done until 2013-14 when Linc Energy drilled two wells, Umiat 18 and Umiat 23H. Umiat 23H was tested with a maximum flow rate of 800 barrels per day and sustained flow of 200 barrels per day, 88 Energy said.