Complex sentence: In April 2007, it was charter contracted by Petrobras for serving as the Pecém LNG terminal, after which in 2007--2008 the vessel was converted at the Keppel Shipyard in Singapore.
Split into simpler sentences: In April 2007, it was charter contracted by Petrobras for serving as the Pecém LNG terminal. During 2007 and 2008 the vessel was converted at the Keppel Shipyard in Singapore.