Structural Interpretation of a Complex Multi-Reservoir Field, NW Niger Delta

This paper outlines the appraisal and development of the ‘G’ Field, in the north-western part of the Niger Delta. The field has a stacked series of reservoirs, of which the most valuable are the deeper ‘E’ units, lying at depths between -9,000 to -10,500 ftss. The terrain is mangrove swamp, with several rivers and channels cutting through the licence area. The resultant seismic quality is often sub-optimum, particularly at the deeper reservoir levels where the structure is more complex. A thorough understanding of the structural form of these deeper reservoirs is key to optimum future well placement, accurate reserves / resources determination, and for input into realistic history matching models. This paper outlines the progression of understanding of structural definition from field appraisal through to mature development stage. It demonstrates the importance of well data acquisition throughout these phases, and shows how the integration of multi-disciplinary interpretation is vital for structural definition, particularly for areas of subtle faulting where seismic mapping does not provide all of the answers.