Characterizing complex slope channel reservoirs applying Extended
Elastic Impedance, Saffron gas field, offshore Nile Delta, Egypt
In a complex reservoir with such a significant degree of heterogeneity,
it’s a demand to characterize the reservoir using different seismic
attributes based on the available data within certain time constraints.
Pre-stack seismic inversion and Amplitude variation with offset (AVO)
are among those techniques which give excellent results in particular
for the gas bearing clastic reservoirs delineation because of the
remarkable contrast between the latter and the surrounded rocks.
However, challenges arise of data shortage in seismic and /or well data
may obstacle applying these techniques. Moreover, if the prediction of
water saturation (Sw) is needed using the seismic data, it represents a
serious challenge because of the independent nonlinear relationship
between water saturation and seismic attributes and inversion products.
Prediction of water saturation is necessary not only for characterizing
pay from non-pay reservoirs but for the economics also. Therefore,
Extended Elastic Impedance has been performed to produce a 3D volume of
water saturation over the reservoir interval then, 3D Sweetness volume
was used in order to grasp the geometry of the sand bodies that have
been charged with gas in addition to its internal architecture which
could illustrate the different stages in the evolution of the Saffron
channel system and the sand bodies distribution both vertically and
spatially consequently increase the production and decrease the