Wellesley Petroleum Makes Successful Discoveries in the North Sea

Wellesley Petroleum Makes Successful Discoveries in the North Sea

Wellesley Petroleum, the operator of production license 1148 in the North Sea, has achieved success with two wildcat wells, according to the Norwegian Petroleum Directorate. The wells, named 35/10-10 S and 35/10-10 A, were drilled 15.5 miles northwest of the Troll field.

The primary goal of well 35/10-10 S was to prove the presence of petroleum in Middle Jurassic reservoir rocks in the Etive and Oseberg formations within the Brent group. The secondary objective was to confirm petroleum in the Early Jurassic Cook formation. The well successfully encountered a gas-condensate column measuring 690 feet in the Ness, Etive, and Oseberg formations. However, the sandstone reservoir quality was reported to be poor to moderate.

In addition, well 35/10-10 S discovered a gas-condensate column of 230 feet in the Cook Formation, with poor-quality sandstone reservoirs totaling 75 feet. Furthermore, a 42-foot oil column was encountered in the Early Jurassic Amundsen Formation in the Dunlin Group, with poor-quality sandstone reservoirs.

The appraisal well, 35/10-10 A, aimed to determine the petroleum-water contact in a lower section of the structure and collect liquid samples from the aquifer. It successfully encountered a gas-condensate column of 787 feet in the Ness, Etive, Oseberg, and Cook formations. The sandstone reservoir quality was reported to be poor to moderate, totaling 165 feet. Water was also found in the Cook formation at a depth of 13,640 feet below sea level.

Preliminary estimates suggest that the discovery has a recoverable oil equivalent ranging from 317.8 million standard cubic feet to 1.6 billion standard cubic feet. The licensees are planning early-phase development studies and considering additional appraisal wells to further explore the discovery.

These two wells represent the first exploration activities in production license 1148, which was awarded in APA2021. The water depth at the site is 1,180 feet, and both wells have been permanently plugged and abandoned.

The Deepsea Yantai drilling facility, responsible for drilling these wells, will now move on to drill a wildcat well in production license 984 in the North Sea, where DNO Norge is the operator.

Published: 24-07-2023