Project Leonis


Operator | 100% WI ~26k acres (10 leases)

  • Maiden internal Prospective Resource estimate completed at Project Leonis.
  • Total estimated net mean Prospective Resource of 381 million barrels (MMbbls) of oil1,2 recoverable from the Upper Schrader Bluff Formation (USB).
  • Unrisked net 3U (high) of 671 MMbbls, 2U (best) of 338 MMbbls and 1U (low) of 167 MMbbls1,2.
  • Permitting and planning has commenced for the newly named Tiri-1 exploration well designed to test the Tiri prospect in the USB Formation.
  • The Tiri prospect has exceptional estimated porosity, averaging almost 30% over the 175 feet of interpreted pay.
  • Concurrent farm-out process ongoing to secure a funding partner ahead of drilling.

In November 2022, 88 Energy was the highest bidder on 10 leases covering approximately 25,600 contiguous acres immediately south of Prudhoe Bay on the North Slope of Alaska with formal award in April 2023.

The acreage, referred to as Project Leonis, is covered by the existing Storms 3D seismic data suite and contains the historical exploration well Hemi Springs Unit #3 (drilled by ARCO in 1985).

Project Leonis is superbly located adjacent to TAPS and the Dalton Highway, enhancing future potential development commercialisation.

Preliminary interpretation of modern Storms 3D seismic identified that the Upper Schrader Bluff (USB) reservoir penetrated by Hemi Springs Unit 3 is isolated from other wells in the vicinity.

The USB reservoir is a producing unit to the North (including the West Sak and Polaris fields, amongst others).

Hemi Springs 3 reported “oil over shakers” at multiple depths; it was later abandoned when deeper primary targets were not correspondent with oil shows.

88E’s active preliminary data examination has calculated over 200 ft of net pay in the USB reservoir using modern log analysis techniques.


88 Energy has engaged Fairweather to assist in commencing the planning and permitting for the Tiri-1 exploration well. The well will be designed to drill, log and test the USB zone in a single season, and will utilise the existing gravel pad at the location of the Hemi Springs Unit-3 well to reduce costs.


IMMEDIATELY SOUTH OF PRUDOE BAY (Proven petroleum province)

  • Including UPPER SCHRADER BLUFF (USB) Reservoir.


  • Hemi Springs Unit 3 well drilled in 1985
  • Hailstorm-1 well drilled in 2006
  • In 2022, acquired modern Storms 3D Seismic shot in 2005
  • Reprocessed the Storms 3D in 2023.


  • USB reservoir is a producing unit to the North (West Sak and Polaris Fields).


  • Deeper targets were the focus in 1985.

88E Preliminary data review calculated > 200ft of logged net pay in the USB reservoir

  • Importantly this was using Modern log analysis techniques not available in 1985.

Figure: Time slice of Edge Detection attribute run on the Storms 3D seismic. Edge detection attribute clearly shows NW-SE normal faulting as well as a NE-SW feature which separates the reservoir at Hemi Springs Unit 3 from that of nearby Hailstorm-1.

The assessed maiden Prospective Resource estimate associated with 88 Energy’s Project Leonis acreage (100% working interest) is summarised below.

Project Leonis: Alaska North SlopeUnrisked Gross Prospective Oli Resources (MMbbls) 5,6
Prospect (Probabilistic Method)Low (1U)Best (2U)High (3U)MeanCOS4
Tiri Prospect (Upper Schrader Bluff)20040680645832%
Project Leonis: Alaska North SlopeUnrisked Net Entitlement to 88E Prospective Oil Resources (MMbbls) 3,5,6
Prospect (Probabilistic Method)Low (1U)Best (2U)High (3U)MeanCOS4
Tiri Prospect (Upper Schrader Bluff)16733867138132%

The data used to compile the prospective resource report includes reprocessed 3D seismic data as well as thorough petrophysical analysis of publicly available wells and historical geological records. The data was compiled and interpreted by 88 Energy.

  1. Cautionary Statement: The estimated quantities of petroleum that may be potentially recovered by the application of a future development project relate to undiscovered accumulations. These estimates have both an associated risk of discovery and a risk of development. Further exploration, appraisal and evaluation are required to determine the existence of a significant quantity of potentially recoverable hydrocarbons.

  2. Net Unrisked Prospective Oil Resources (MMbbls). Refer to ASX announcement dated 4 June 2024 for further details.
  3. 88 Energy net resources have been calculated using a 100% working interest and a 16.6667% royalty.
  4. COS represents the geological chance of success as assessed by 88 Energy, taking into account and risking of such factors as source, timing/migration, estimated reservoir and quality, mapped closures and seal effectiveness.
  5. Prospects are subject to a phase risk (oil vs gas). Chance of oil has been assessed as 100%. Phase risk has not been applied to the unrisked numbers.
  6. The Prospective Resources have not been adjusted for the chance of development. Quantifying the chance of development (COD) requires consideration of both economic and other contingencies, such as legal, regulatory, market access, political, social license, internal and external approvals and commitment to project finance and development timing. As many of these factors are not yet known, 88 Energy has qualitatively assessed the chance of development as “probable” upon geological success given the strategic location of the acreage position adjacent to TAPS and key infrastructure.

"Award of the new acreage demonstrates 88 Energy's commitment to continued exploration on the North Slope and presents as an attractive exploration proposition. The acreage benefits from a historical well, which indicated oil shows and calculated pay in the USB zone of interest, and an existing 3D data suite".

Ashley Gilbert, Managing Director

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