This article describes the debottlenecking operation of the production separators on the Shell Leman AK platform in the southern North Sea The original, compactly built separators became overloaded through decreasing well pressures. Gradually, they were forming a serious restriction in the production flow sheet. Two alternatives were considered to overcome this problem : (1) extending the platform and installing new separators or (2) retrofitting the old separator vessels with state-of-the-art internals. The second alternative was chosen because of considerably lower costs (totaling only 10% of first alternative) and considerably shorter downtime, This separator upgrade was a joint project between the operator of the field and their central research and engineering facilities and Burgess Manning, Technical U. of Delft, and CDS Engineering BV.