Wintershall Norge AS drilled the Maria Appraisal Well #6407/1-5 S l in the Norwegian Sea, and encountered a 128-ft (39-m) thick oil column in the Garn formation. The oil-water contact in the well was the same as in the discovery well, and pressure data indicate communication between north and south. The discovery is delineated to the north. A successful formation test has been carried out.

The well is about 12 miles (20 km) east of the Kristin field, and about 5 miles (8 km) northeast of the Maria discovery Wintershall made in 2010. The purpose of the appraisal well was to delineate the Maria discovery and prove hydrocarbons in the northern extent of the structure.

The well was drilled by the mid-water semisubmersible facility Borgland Dolphin to a total depth of 13,560 ft (4,133 m) below the sea surface and terminated in the Tilje formation in the Lower Jurassic. The water depth at the location is 974 ft (297 m).

"Our preliminary calculations do not only confirm our original resource estimates, but support the upper end of our discovery volumes," said Bernd Schrimpf, managing director of Wintershall.

"The extensive data we have acquired with the appraisal well will further support our analysis for an optimum development concept for Maria, either a subsea tieback or a standalone development," added Maria project manager, Hugo Dijkgraaf. "Proving oil in the northern extent of the structure has always been the strong goal of our technical team."

Wintershall, operates the Maria well, with 50% working interest; Petoro AS, 30%; and Centrica Resources AS, 20%.