By Joyce Lee and Florence Tan SEOUL, June 2 (Reuters) – Korea Shipbuilding & Offshore Engineering (KSOE) has mostly filled its order book for the next 2-1/2 years as the pandemic drove demand for container ships, leaving little room to meet the needs of the liquefied natural gas (LNG) sector, a senior company executive said. With U.S. LNG exports rising, more LNG carriers are travelling longer distances to customers in North Asia and Europe while European countries have snapped up floating storage and regasification units (FSRUs) as they ramp up LNG imports to replace Russian gas supplies in the wake…