Deltic Energy has announced a significant gas discovery at the Selene prospect in the southern North Sea, marking a major find in the UK's offshore energy sector.
The Shell-operated 48/8b-3Z well reached a total depth of 3,540m, encountering a 160m-thick section of Leman Sandstone, a key indicator of the presence of gas.
The top of the Leman Sandstone was discovered approximately 70m deeper than anticipated, with elevated mud gas readings throughout the reservoir interval and into the Carboniferous basement below.
Wireline logging and fluid sampling have confirmed a live gas column above a gas-water contact at approximately 3,370m within the B-Sand, the prime producing interval of the Leman Sandstone.
Deltic's updated volumetric model estimates that the Selene discovery contains gross P50 estimated ultimate recoverable resources of 131 billion cubic feet (bcf), aligning with the lower end of pre-drill forecasts.
The discovery's recoverable resources are predominantly located in the high-quality B-Sand up-dip from the well location, potentially enabling a more cost-effective development with higher gas production per well than initially projected.
However, a shallower gas-water contact and a deeper structural crest have led to reduced gas column heights across the structure.
The B-Sand encountered in the well was 53m thick, with an average porosity of 12.1% and gas saturation in line with expectations.
Downhole testing recovered gas samples and indicated permeabilities 1–5 millidarcies (mD) above the gas-water contact, supporting the use of more favourable recovery factors for the B-Sand.
After the rig is demobilised, Deltic will conduct a detailed analysis of the data to refine the geological model, volumetric estimates and development plans.
The company will also re-evaluate the Endymion prospect, another low-risk Leman Sandstone opportunity that could be integrated into the Selene development.
Deltic Energy CEO Andrew Nunn said: “We are looking forward to engaging with Shell and Dana as we work through the customary post-well analysis and preparation of a plan which will move the Selene discovery towards development over the coming year.
“We continue to believe that the asset can create material value for our shareholders."
