Dolphin Drilling, an Oslo-listed, Aberdeen-headquartered owner and operator of a fleet of three harsh environment mid-water and deep-water semi-submersible drilling rigs, has firmed up a multimillion-dollar assignment for its 36-year-old semi-submersible rig on the UK Continental Shelf (UKCS), while the firm’s 52-year-old unit remains on duty off the coast of India.