The Tern field was discovered in April 1975 by well 210/25-1, drilled by semi-submersible rig Sedco 135G in a water depth of 167 metres (548 ft).
On 7 July 2008, it was purchased by TAQA Bratani, a subsidiary of the Abu Dhabi National Energy Company, along with the Eider, North Cormorant, Cormorant Alpha, Kestrel and Pelican fields and related sub-sea satellite fields.
[3] Structurally, it is a triangular uplifted block of the Brent Group bounded by NNW-SSE and NNE-SSW trending faults and sealed by overlying Kimmeridge Clay (the dominant source rock, with debated contributions from the much deeper Old Red Sandstone) and Shetland Group mudstones.
Compressed gas is used for gas-lifting both the Tern and Hudson oil production wells.
[3] The Tern platform later added the Kestrel Field, located in 211/21a, this small subsea tieback started production in 2001.