JAMAICA’s long-running offshore oil exploration effort has entered what operators describe as its most decisive stage yet, with United Oil & Gas plc beginning piston coring operations on the Walton-Morant licence.

The UK-listed explorer announced on Monday that it has completed seabed heat-flow measurements and has now launched stage three of its Surface Geochemical Exploration programme — a phase designed to physically test whether hydrocarbons are present beneath Jamaica’s offshore basins. Up to 42 sediment cores will be taken, primarily within the Walton Basin near the Colibri, Streamertail and Oriole prospects, with additional locations identified in the Morant Basin.

Testing whether Jamaica has an active petroleum system

Unlike seismic surveys, which interpret underground structures using reflected sound waves, piston coring retrieves actual seabed sediment samples. These are analysed for thermogenic hydrocarbons — hydrocarbons generated by heat and pressure deep underground. If detected, they would provide direct evidence that Jamaica’s offshore acreage hosts an active petroleum system.

“The completion of heat-flow measurements and commencement of piston coring marks a major step forward in our Jamaica exploration programme,” said chief executive Brian Larkin.

“Piston coring is the defining phase of this programme, providing the opportunity to physically confirm the presence of thermogenic hydrocarbons offshore Jamaica.”

Samples will be shipped to Houston, Texas, for laboratory analysis once collection is complete. Operations are expected to last about one week, weather permitting.

Why this matters for Jamaica

Jamaica has pursued offshore oil exploration intermittently for decades, but commercial production has never materialised. The Walton Basin has long been considered geologically promising, though it remains largely underexplored compared with other Caribbean jurisdictions.

Confirmation of thermogenic hydrocarbons would not mean oil production is imminent, nor would it confirm commercially recoverable volumes. However, it would significantly reduce geological uncertainty and strengthen the technical case for future drilling.

That matters not only to United, but to Jamaica’s broader energy outlook.

Fuel and lubricant imports totalled US$1,371.8 million in the first nine months of 2025, accounting for roughly one quarter of all goods imported during the period, according to the Statistical Institute of Jamaica. With the country recording a visible trade deficit of US$4,375.8 million over the same period, any confirmation of an active offshore petroleum system would carry long-term implications not just for geology, but for Jamaica’s persistent external imbalance.

Jamaica remains heavily dependent on imported fuel for electricity generation. While renewables are expanding, fossil fuels still account for the majority of the energy mix. A viable offshore petroleum discovery, if ever realised, would reshape the country’s import bill and potentially alter its fiscal and energy landscape.

Any eventual offshore development would depend on securing industry partners and substantial capital investment, given the high cost of deep-water drilling.

At this stage, however, the work remains firmly within the realm of technical validation.

De-risking before deeper commitments

United said earlier seabed mapping and seismic integration helped identify features of interest and optimise the 42 coring locations. In frontier basins like Jamaica’s, companies typically seek to “de-risk” acreage through geochemical confirmation before committing to the substantial costs of offshore drilling. Deep-water wells can cost tens of millions of US dollars, making early stage validation critical.

For Jamaica, the upcoming laboratory results will be closely watched. Positive indications could attract further industry interest or farm-in partners. Inconclusive findings would prolong uncertainty. Either way, the piston coring campaign marks one of the most technically consequential offshore surveys undertaken in Jamaican waters in recent years.

For now, the next milestone rests not offshore — but in the laboratory results.

LARKIN…the completion of heat-flow measurements and commencement of piston coring marks a major step forward in our Jamaica exploration programme.