The Jethro discovery on Guyana’s Orinduik Block is back in focus as a potential standalone offshore development, with operator Eco Atlantic reassessing its commercial viability following ExxonMobil’s sanctioning of the Hammerhead heavy oil project in the neighbouring Stabroek Block.
Jethro-1 was first drilled in August 2019, encountering 55 metres of net oil pay in lower tertiary sandstone reservoirs. At the time, Tullow Oil, then the block’s operator, estimated the discovery held more than 100 million barrels of recoverable oil and described it as having commercial and fiscal terms that supported standalone development. Tullow Chief Executive Paul McDade said the results exceeded expectations and expressed confidence in the prospect’s commercial value.
The Orinduik Block lies approximately 170 kilometres offshore in the Guyana-Suriname Basin and covers 1,800 square kilometres. Eco Atlantic is currently the sole block holder following the exit of former partners Tullow and TotalEnergies.
Interest in Jethro was renewed in August 2022 when Eco brought in a third-party consultant with heavy oil expertise to assess drilling and production scenarios. The company noted that the discovery’s reservoir characteristics, including a pressure of 8,500 PSI, a reservoir temperature of 94 degrees Celsius and an estimated flowing wellhead temperature of 90 degrees, were favorable for a floating production facility.
The development case gained further momentum in October 2025, when Eco Chief Executive Gil Holzman said ExxonMobil’s Hammerhead sanction had demonstrated that heavy oil offshore Guyana could be made economical. He said the development prompted Eco to take a fresh look at Jethro and potentially recall a non-commercialisation notice previously issued on the discovery. Holzman also indicated the company was exploring farm-out and licence options while seeking revaluation rights for the prospect.
As of 2026, that October 2025 update remains the latest public signal that Jethro is still being considered as a possible standalone development.
SOURCE: OilNOW, “Orinduik’s Jethro back in focus as standalone development candidate,” April 12, 2026
