Tullow wraps up Jamaica’s first 3D seismic survey
UK-based Tullow Oil has completed a 2,250 sq km 3D seismic acquisition survey over the Walton-Morant licence offshore Jamaica, which includes the high-graded Colibri target.
Tullow holds an 80% interest in the license and the remaining 20% is held by United Oil & Gas, a London-listed oil and gas exploration and development company.
United informed on Monday that the 3D seismic survey, the first in Jamaica, was completed under-budget and a week ahead of schedule by the Polarcus Adira vessel, which started the survey in April.
The survey is centered on de-risking a number of highly prospective Cretaceous and Tertiary aged clastic and carbonate reservoir targets that have previously been mapped by Tullow on reprocessed and reinterpreted 2D seismic data.
These include the Colibri target, which has been estimated to hold gross unrisked mean-case prospective resources of over 200MMstb. The technical case for Colibri is further strengthened by the recent identification of an active thermogenically derived offshore oil seep to the south of the structure.
United said it expects to receive a fast-tracked version of the data by mid-July 2018 with the final processed data-sets due to be available later in the year. Subject to the results, an exploration well could be drilled in 2020-2021, with success significantly de-risking numerous follow-up structures that have already been identified across the license.
Key to de-risking Colibri
United CEO, Brian Larkin, said, “With prospective resources of over 200mmbbl estimated for the Colibri target alone and with multiple copycat structures already identified, Walton-Morant has clear potential to be transformative for United.
“The completed 3D seismic survey is key to de-risking Colibri and other structures to the point where they are drill ready. We are highly encouraged that the survey has been completed ahead of schedule and we now look forward to receiving the fast-tracked data set in 2Q 2018.”
According to United, the large 32,065 sq km Walton-Morant license, offshore Jamaica, is exposed to a number of different plays across three geological basins including the Walton and Morant Basins. To date, only 11 wells have been drilled across the whole of Jamaica’s onshore and offshore, and despite challenges with well placement due to a lack of seismic control, 10 of these encountered hydrocarbon shows. Oil-prone source rocks have been identified in the Eocene and in the Cretaceous, with migrant oil identified in onshore wells and outcrop samples. This provides good evidence of the presence of regional source rocks, said United.
Recent work, including extensive onshore fieldwork, has confirmed the presence of all the elements required for a working petroleum system, and has also identified a thermogenically derived offshore oil seep close to Colibri, the main prospect of interest, providing further confidence that there is the potential to find significant commercial volumes within the Licence. Colibri has been high graded on the basis of its position in relation to migration routes out of an identified Eocene kitchen.
Tullow entered the Walton-Morant license in November 2014. In addition to securing a portfolio of legacy 2D seismic data, Tullow also acquired a further 3,650 km of 2D seismic in 2016 and 2017. Interpretation of the data set has identified attractive Cretaceous and Tertiary aged clastic and carbonate reservoir targets. The 3D seismic survey is designed to further de-risk these targets, specifically the high-graded Colibri lead.
— PCJ (@PCJEnergyja) May 4, 2018