Drilling operations on a frontier probe off the northern coast of Latin America have been extended by operator Shell.

Partner Northern Petroleum said current drilling operations on the Guyane Maritime permit offshore French Guiana are being extended. The GM-ES-3 (Priodontes-1) exploration well is the second of a 4-well drilling campaign that started last year to follow up an initial oil discovery made with the GM-ES-1 wildcat on the Zaedyus prospect in 2011.

The GM-ES-2 well had exploration objectives in the major Cingulata fan system within which the original oil discovery was made in two ages of formation. GM-ES-3 has been planned to deliver exploration information in the subsidiary Priodontes fan system to the northwest of the original Zaedyus discovery.

Well GM-ES-3 intersected a 50 m (164 ft) gross section of oil-stained sands in the lower part of the Bradypus fan, which was not a target formation at this location although it is also within the main Cingulata fan system. A 325 m (1,066 ft) gross interval of sandstones was encountered in the targeted Priodontes fan, but this was logged with no significant hydrocarbon shows.

Shell and its partners Total, Tullow Oil, and Northpet Investments Ltd. decided that the well is a suitable location to drill deeper in a plan to penetrate the full post Atlantic rift sequence. The duration of this additional drilling will depend upon results from the formations encountered. The well is now planned to reach a final depth of 6,438 m (21,122 ft), subject to operational factors.

Derek Musgrove, Managing Director of Northern, said: “Following the oil discoveries of GM-ES-1 in 2011, the task before us was to explore the licence to ascertain its wider potential. Whilst the sand package in the primary target proved not to have significant hydrocarbons at this location, the oil staining encountered in the Bradypus fan is encouraging of the broader active hydrocarbon systems and potential. Northern supports this fuller exploration approach to this well. It is likely to provide partners with further geological data imperative to gaining further understanding of the complex geology in this area.”

Partner Tullow added that although the Priodontes well has not so far encountered significant hydrocarbons, it believes this is due to a trap-specific issue and has no follow-on consequences for prospectivity elsewhere in the block.