De-risked prospects on the UKCSGlengorm Castle. Photo: PaulT (Gunther Tschuch)/Wikimedia Commons

De-risked prospects on the UKCS

Glengorm, the largest discovery in more than a decade, may have de-risked similar HPHT gas-condensate prospects.

The discovery of the 250 mmboe gas and condensate field in the North Sea was first announced in January of last year. CNOOC is the operator (50 % interest), while partners Total and Neptune Energy each hold a 25 % interest.

The field is the largest discovery in the central North Sea in over a decade, and the largest on the UK shelf since the Culzean gas field was discovered in 2008.

According to the energy research and consulting firm Rystad Energy, global discoveries of oil and gas in 2019 were the highest since 2015. And they consider Glengorm a key offshore discovery, highlighting the recent exploration efficiency on the UKCS.

Despite low levels of exploration activity in the 2016 to 2018 period, commercial success rates were around 38 %, above the global average, the firm says.

CNOOC will present the Glengorm discovery under the conference NCS Exploration – Recent Discoveries in Oslo on the 12th – 13th of May


Pressure, patience and persistence

Bas Spaargaren, Vice President Exploration & Appraisal, Europe & Africa at CNOOC International, gave a talk on Glengorm at the Prospex 2019 conference in London in December.

– The three P’s; pressure, patience and persistence, these are the key elements behind the successful discovery of Glengorm, Spaargaren.

According to Spaargaren, the prospect had existed for years, and other oil companies had previously held and given up on it. Then, CNOOC wanted to give it a try. A lot of 3D seismic data were acquired, and some failed drilling attempts followed. However, the company did not give up, and in the end, their persistence and patience paid off.

Glengorm is situated in a high-pressure area, which represented a challenge before and during drilling. The pre-drill prognosis was however almost identical to the actual result, a feat CNOOC, of course, was very pleased with.

Illustration: Rystad Energy

May spark new interest

Rystad Energy believe the discovery has been important for the UKCS as it may spark new interest in the years to come.

– With further appraisal and exploration likely to be undertaken, the Glengorm area will likely be an industry hotspot in the coming years, said Rystad Energy principal Simon Sjøthun in a press release following the discovery.

– The proximity to infrastructure, the reported high quality reservoir and follow up potential all point to Glengorm becoming a large new field development on the UKCS, Rystad Energy senior analyst Sonya Boodoo added.

Boodoo further notes that Glengorm carries similarities to the Culzean project, which is another high pressure/high temperature gas-condensate reservoir. This means that other similar prospects have now been de-risked.

– It is likely that the Glengorm license will target these prospects in the near to medium term. If successful, this could pave the way for a Glengorm area development, Boodoo said.