ExxonMobil Exploration and Production Romania Limited, the Romanian unit of the US’ oil giant, and OMV Petrom, the largest oil&gas company in Romania, have started drilling the Pelican South-1 exploration well on a new prospect in the Neptun Block, the companies said in a statement.

“The Ocean Endeavour rig is drilling the Pelican South-1 wildcat well about 155 kilometers offshore in the Romanian sector of the Black Sea.”

The well will test a new geological structure on the Neptun Block. Earlier in October, the Ocean Endeavour rig completed drilling the Domino-2 well and data from the well are being evaluated, the statement reads.

“Exploration for oil and gas in frontier areas is complex and very detailed, often taking years to complete. A thorough understanding of the geology is essential prior to making the significant investments required to develop such a discovery,” said John Knapp, managing director of ExxonMobil’s affiliate in Romania.

In February 2012, ExxonMobil and Petrom announced a discovery of a natural gas field estimated at 42-84 billion cubic meters following the drilling of a first well in the block.

“The Black Sea region plays a central role in our strategy and we allocate significant financial and technical resources to the offshore projects. We are encouraged by the good results so far, in shallow and deep waters. However much of the activity in the Black Sea deepwater area is of a frontier, pioneering nature, involving high investment risks and therefore requiring a stable investment framework,” said Gabriel Selischi, member of OMV Petrom Executive Board responsible for Exploration and Production.

ExxonMobil Exploration and Production Romania and OMV Petrom each hold 50 percent of the deepwater sector of the Neptun Block.