Supermajor Shell has made one of the largest natural gas discoveries in the Southern North Sea in over a decade.

The discovery in question is the Pensacola prospect which holds P50 Estimated Ultimate Recovery resources of 302 billion cubic feet.

The drilled well, designated 41/05a-2, reached a total depth of 1,965 meters true vertical depth subsea, and the presence of mobile gas and oil in the primary Zechstein Hauptdolomite carbonate target interval was confirmed via wireline logs.

The well encountered the top Hauptdolomite reservoir at 1,745 meters and confirmed a reservoir thickness of 18.8 meters with better-than-expected porosity averaging 16 percent. As planned, the well penetrated the edge of the Pensacola structure in a down-dip location and has proven a substantial hydrocarbon column.

Post acidization, the well flowed gas at peak rates of around 4.75 million standard cubic feet per day declining to 1.75 million standard cubic feet per day after the 12 hours of the test. These results align with the pre-test expectations based on the reservoir parameters derived from the well.

Being located down dip, the flow rates observed during the well test are not expected to be representative of flow rates of potential future production wells which would likely target the central part of the Pensacola structure and are expected to generate higher rates.

Light oil with a preliminary gravity of 34-36° API was also produced at a rate of approximately 18 barrels per day during the well test. The potential of this oil with respect to the Pensacola opportunity is yet to be determined.

Based on the data collected during drilling and testing, it is estimated that the Pensacola discovery contains P50 EUR of 302 billion cubic feet – P90 to P10 Range of 164 to 519 bcf – fully aligned with pre-drill guidance. The well will now be plugged and abandoned and the Noble Resilient will be demobilized from the site.

The Pensacola well is located on Licence P2252 in the Southern North Sea and is operated by Shell with a 65 percent stake. Deltic holds 30 percent while ONE-Dyas holds the remaining 5 percent.

In a statement released by Deltic, Chief Executive of the company Graham Swindells made his comment on the discovery.

“Deltic’s first exploration well at Pensacola has resulted in a highly positive outcome and, at approximately 300 bcf, would represent one of the largest natural gas discoveries in the Southern North Sea in over a decade.”

“This discovery is a major milestone in the development of our company as we continue to execute our exploration-led strategy and progress our portfolio of high-quality drilling opportunities as we seek to create value for our shareholders.”

“We believe that the Pensacola discovery will open a new Zechstein play in this mature basin and highlights the remaining potential of the North Sea as a source of further discoveries which can provide domestically produced natural gas, supporting UK energy security while we transition toward a net zero economy.”

“As we continue our preparations for drilling the Selene well, we are now looking forward to working with our partners as we continue to progress this exciting and significant gas discovery at Pensacola and look forward to updating the market on our future plans,” Swindells concluded.