The Edmonton Oilers signed defenseman Ryan Shea to a five-year, $20 million contract on Wednesday, filling a gap left by the trade of Darnell Nurse to the San Jose Sharks earlier that same day. Shea, a 29-year-old native of Milton, Massachusetts, spent the past three seasons with the Pittsburgh Penguins, where he became a reliable presence on the blue line despite not making his NHL debut until age 26.