DUBLIN, Ireland (CMC) —The Irish-based exploration company, Tullow Oil, Monday said that it had discovered “high-quality” oil bearing sandstone reservoirs after drilling the Jethro-1 exploration well in the Orinduik Block offshore Guyana in the Caribbean.

“This substantial and high value oil discovery in Guyana is an outcome of the significant technical and commercial focus which has underpinned the reset of our exploration portfolio,” said Paul McDade, the chief executive officer of Tullow Oil.

“It is an excellent start to our drilling campaign in the highly prolific Guyana oil province. We look forward to drilling both the Joe and Carapa prospects in our 2019 drilling campaign and the material follow-up exploration potential in both the Orinduik and Kanuku licences,” he added.

The Guyana Government had earlier Monday announced the discovery of oil in commercial quantities.

“This is a major development for the Co-operative Republic of Guyana (CRG) as it adds to the further de-risking of the deep and ultra-deep zone. Furthermore, it offers significant potential for the diversification of the CRG’s hydrocarbon production base,” said the director, Department of Energy in Guyana, Dr Mark Bynoe.

The Jethro-1 well was drilled by the Stena Forth drillship to a total depth of 4,400 metres in approximately 1,350 metres of water.

Bynoe said the Jethro-1 well is the first discovery on the Orinduik Block and comprises high-quality oil-bearing sandstone reservoirs of Lower Tertiary age.

He explained the well encountered 55m of net oil pay, which supports a recoverable oil resource estimate that exceeds Tullow’s pre-drill forecast.

“The Department of Energy (DE) is encouraged by the prolific rate of discovery in the CRG and will continue to work assiduously and conscientiously to extract optimum value from these resources for all the peoples of our country.”

In a statement, Tullow Oil, the well encountered 55 metres of net oil pay, which it said supports a recoverable oil resource estimate that exceeds its pre-drill forecast.

The company said it would now evaluate the data from the Jethro discovery and determine appropriate appraisal activity.

Tullow said the discovery “significantly de-risks” other Tertiary age prospects on the Orinduik licence, including the shallower Upper Tertiary Joe prospect, which will commence drilling later this month following the conclusion of operations at the Jethro-1 well.

The Carapa-1 well will be drilled later this year on the adjacent Kanuku licence.

Tullow Guyana BV operates the Orinduik block with a 60 per cent stake. Total E&P Guyana BV holds 25 per cent stake while the remaining 15 per cent is being held by Eco (Atlantic) Guyana Inc.