Wellesley took over operatorship of the Grosbeak discovery and drilled two successful appraisal wells in 2018, confirming significant volumes of oil and gas in Brent and Sognefjord reservoirs. The field is now fully appraised with 6 well penetrations and a large dataset including 2 DSTs, 677m of core, logs and PSDM seismic. The appraisal campaign found multi-Darcy reservoirs with good horizontal connectivity, 44° API oil and low CO2 gas.

Licence PL090 JS, PL248I, PL925
Wellesey 5%
Partners Equinor 58.75% (op), Petoro 24.8%, Idemitsu 6.8%, Neptune 4.65%
CO2 intensity <2kg CO2/boe over entire field life

Grosbeak – Net Wellesley Production (kboe/d)

Grosbeak Production Forecast (kboe/d)

6.2 mmboe net Wellesley

Grosbeak mmboe net Wellesley


In 2021, Wellesley completed a swap transaction to transfer operatorship to Equinor, aligning operatorship with the other FANTA development projects and with the Troll host infrastructure. Grosbeak is expected to be developed as part of the FANTA project, with 3 oil producers, 3 water injectors and up to 2 gas producers.