The full-length paper is a case study of the redevelopment of a marginal, small sized North Sea oil field and describes some of the key aspects of the process that led to the identification of a viable drilling target in a field that already had seen reasonably high recovery factors (> 25%). In particular, the use of analytical and simple numerical models to constrain key parameters before undertaking integrated full field simulation is considered. The two main themes running through this description are, "understand before simulating" and "the quicker you fail, the quicker you succeed". There are examples illustrating how this approach allowed for parameters such as the STOIIP and vertical heterogeneity to be quantified more simply and quickly prior to integrated full field simulation modelling in the main paper. The Goosander field is part of the Greater Kittiwake Area group of fields and is situated 95 miles East North East of Aberdeen in the UK Central North Sea.