A CPR carried out for Eco Atlantic by Gustavson Associates LLC has increased the gross prospective resources (P50) in its Orinduik Block, offshore Guyana, from 2,913mmboe to 3,981mmboe. The new figure was assessed after taking into account ExxonMobil’s Hammerhead Tertiary discovery, together with the processing and interpretation of 2,550km2 3D seismic acquired in 2017.
The bulk of the increase is due to the addition of five new leads, of which four, Jethro, Jethro Ext, Joe and HH are all targeting the Tertiary.
Jethro will be the first well to be drilled as part of a two well campaign in the block led by operator Tullow Oil and is due to spud in Q2 2019 (The well was included in our ‘Exploration Watch:2019 exploration wells’ report) Eco had previously estimated Jethro to hold P50 resources of 250mmboe and this has been revised by Gustavson to 214.5mmboe. With the success at nearby Hammerhead, the Tertiary leads all carry relatively high chances of success (COS) in the CPR. Jethro, Jethro Ext and Joe all carry a geological COS of 43.2%, with the key risk being a lack of seal. As the HH lead is considered to be the extension of Hammerhead from the neighbouring Stabroek block into Orinduik, it has a very high COS of 81%, although the volume is assessed to be a modest 11mmbbls.
Upper Cretaceous leads Kumaka and Rappu are the largest targets in the portfolio at 667.5mmbbls and 535.6mmbbls respectively. Both are estimated to carry a higher risk than seen in the Tertiary leads, but still reasonably high for a frontier basin. Kumaka relies on a stratigraphic pinch out and has a COS of 22.4%, while Rappu has a COS of 25.5%.
The JV has not yet announced its choice for the second well in the drilling programme. We suggest that the most likely candidate at this stage is the 148.3mmbbl Tertiary prospect Joe, however this would probably be dependent on the outcome of the Jethro well.
Summary of exploration wells in ‘Exploration Watch’ report:
|2nd Orinduik prospect|