Around 1500 barrels of oil were thought to have flowed into the sea at the facility 112 miles east of Aberdeen since a leak in a valve was found in August 2011.
More than 200 tonnes were estimated to be in the outer carrier pipe. The recovery involved the use of subsea pumps to recover oil into storage tanks on a recovery vessel.
The recovered oil is onshore for disposal via a licensed waste oil contractor.
Shell said: "This is an important milestone in the remediation process, which is expected to be completed next year with the removal of remaining oil from the flowline bundle."