Wellesley Petroleum has confirmed the presence of oil and gas at the Gnomoria appraisal well (35/10-12 S) in the North Sea, approximately 100km south-west of Florø, Norway.

This marks the first appraisal well to be drilled in production licence 1184 S, which was awarded as part of the APA 2022.

The COSLPromoter exploration rig conducted the drilling operation.

Preliminary assessments suggest the discovery holds between 0.8 and four million standard cubic metres of recoverable oil equivalent, translating to around five to 25 million barrels of oil equivalent.

Gnomoria is strategically located in a region known for multiple discoveries, and the licensees are now evaluating the potential for a tie-back to nearby existing infrastructure.

The aim of the well was to confirm the presence of petroleum in Upper Jurassic sandstones within the Heather Formation. The well targeted an upflank position, where the reservoir quality was anticipated to be superior, to delineate the Gnomoria discovery initially made in 2018.

During the drilling, Well 35/10-12 S encountered an 11m gas column and an 18m oil column in the Heather Formation. The sandstone layer, measuring a total of 21m, exhibited poor-to-moderate reservoir quality.

The gas/oil contact was found at 3,239m below sea level, while the oil/water contact was not reached.

Although the well was not subject to a formation test, comprehensive data acquisition and sampling were conducted.

The well reached a vertical depth of 3,346m below sea level (3,805m measured depth), concluding in the Upper Jurassic Heather Formation.

The site, with a water depth of 363m, saw the well permanently plugged and abandoned following the completion of the operations.

Wellesley CEO Chris Elliott said: “We are pleased with the Gnomoria result, which adds valuable resources to the ongoing area development plans in the Fram-Toll area. Although modest in size, the discovery has favourable characteristics, which we are confident will allow commercial recovery.

As with Grosbeak, new subsurface ideas have enabled us to rescue stranded resources classed as “unlikely to be developed”, demonstrating the enduring potential for value creation in mature parts of the NCS [Norwegian Continental Shelf]. The operation was highly efficient and we thank COSL and other service providers for an excellent performance in helping deliver a safe and cost-effective well.”