Two oil fields which are characterized by weak natural pressure support and unfavorable rock properties were planned for waterflooding by Esso Production Malaysia, Incorporated. This paper documents the collection and analysis of data for selection of an optimum waterflood pattern. Included will be discussions on parameters that affect short and long term water injectivity, extensive use of numerical models to compare alternate waterflood patterns, on-site production/injectivity. tests to validate predictions and injectivity enhancement methods. With a going-in development plan for an inverted 7-spot waterflood pattern, the final optimum plan was assessed to be a combination of 5-spot and peripheral injection.