Neptune Energy Norge AS advanced Duva development at PL636, 14 km northeast of Gjøa field in the Norwegian sector of the North Sea, with the installation of four enhanced horizontal subsea tree systems (EHXT).
The development, in water depth of 360 m, is an oil and gas subsea tieback to Gjøa’s semi-submersible facility (OGJ Online, June 26, 2019).
The installation was carried out by the vessel Far Samson, operated by Solstad Offshore, instead of a rig—a first for Neptune Energy for a standalone EHXT operation. The systems were deployed on template wellheads over an 18-hr period, with total installation and subsea system testing completed within 8 days in cooperation with TechnipFMC, Ross Offshore, Solstad Offshore, Oceaneering, Fugro, IKM, and Tigmek.
Deploying the subsea trees from a vessel saved about 20 days of rig time, reducing costs by about $12 million, and emissions by about 60%, said Thor Løvoll, director of drilling and wells, Norway.
The Deepsea Yantai drilling rig, operated by Odfjell Drilling, will drill and complete remaining sections of the Duva well program during second- to third-quarter 2021. First production is expected in third-quarter 2021. Gross 2P reserves are 88 MMboe (gas 76%).
Neptune Energy is operator at Duva (30%) with partners Idemitsu Petroleum Norge (30%), PGNiG Upstream Norway (30%), and Sval Energi (10%).