Publications

Structural uncertainty study has been carried out in Sisi Nubi fields. The study has purposes to evaluate the impact of structural variation to volumetric of the fields and to examine the main structural uncertainty contributors. Structurally, Sisi and Nubi fields are characterized by tilted panels separated by major NNE-SSW faults. These faults define 6 main compartments, 4 in Nubi, 2 in Sisi. These compartments are dynamically independent. The styles of hydrocarbon trapping are combination of 3 way dip closures against faults and stratigraphy. The fluid is mainly gas with some oil zones. Since the structures are relatively flat faulted anticlines, small variation of the structure may significantly impact the volumetric assessment. The main elements of this structural uncertainty are velocity model, seismic interpretation (fault+horizon) and fluid contacts uncertainty. After having defined standard deviation map associated to each uncertainty elements, structural simulation is launched for 200 realizations for 9 different scenarios. The simulations calculate the Gross Rock Volume (GRV) of each realization structure. The result of simulation recognised that the main influencing factor to the uncertainty is variation of surfaces.