Wellesley Petroleum has proven oil and gas in the Gnomoria Appraisal (35/10-12 S) well in the North Sea, about 100 kilometres southwest of Florø.
This is the first appraisal well to be drilled in production licence 1184 S, which was awarded in APA 2022. The well was drilled by the COSLPromoter exploration rig. Preliminary estimations of the size of the discovery range between 0.8 to 4 million standard cubic metres of recoverable oil equivalent (Sm3 o.e.). This corresponds to between 5 to 25 million barrels o.e.
Gnomoria is located in an area with multiple discoveries. The licensees are considering a tie-back to existing infrastructure in the area.
Geological information
The objective of the well was to prove petroleum in Upper Jurassic sandstones in the Heather Formation. The well was drilled upflank where reservoir quality was considered to be better for delineation of the Gnomoria discovery from 2018.
Well 35/10-12 S encountered an 11-metre gas column and an 18-metre oil column in the Heather Formation, in a sandstone layer totalling 21 metres with poor to moderate reservoir quality. The gas/oil contact was encountered 3239 metres below sea level. The oil/water contact was not encountered.
The well was not formation tested, but extensive data acquisition and sampling were carried out.
Well 35/10-12 S was drilled to a vertical depth of 3346 metres below sea level (3805 metres measured depth below sea level), and was terminated in the Heather Formation in the Upper Jurassic.
Water depth at the site is 363 metres. The well has been permanently plugged and abandoned.