A fundamental reappraisal of the structure of the Cormorant Field and its impact on field development strategy

Abstract

Production from the Cormorant Field is hampered by complex in-field faulting. The large number of faults and the presence of fault seals combine to restrict fluid flow within the reservoir and locally compartmentalize the field. A reliable structural description of the field is, therefore, a prerequisite for optimal field management. A revised structural framework has been established for the field, based on new and reprocessed seismic data, and the availability of newly developed seismic attribute mapping tools. Previous structural models have emphasized E–W extension on N–S normal faults. The new model also describes E–W extension, but invokes predominantly dip-slip movement on a network of planar, oblique-slip faults, the geometry of which has been strongly influenced by the reactivation of NE–SW-oriented lineaments in the basements. This has led to a significant revision of both the reservoir sub-compartment geometry, and the connected oil volumes associated with existing producer–injector well pairs.