Pulse testing was used in the Fortescue field to clarify reservoir geometries and fluid communication pathways. The high communication levels demonstrated in the test data required a nonstandard analysis of the pressure responses. In addition, proper attention to test planning, data acquisition, and data processing allowed valuable insights into reservoir limits. Most of the structural implications derived from the pulse tests have been supported subsequently by a recent 3D seismic survey of the area. The results and insights gained from these tests are being incorporated into a full-field simulation model of the Fortescue field, which is an integral part of a continuing depletion field study.