Seismic-Scale Integrated Reservoir Characterization of a Permian Fluvio-Aeolian
Gas Reservoir, Waqar Field,
Allan, Saudi Aramco,
An integrated geological model of the Permian ‘Unayzah A fluvio-eolian g
as reservoir, Waqar Field,
Lineation analysis of seismic structure maps tied to wells suggests the existence of minor faulting that may create either reservoir baffles or potential reservoir compartments. The existing seismic structural interpretation was reexamined for subtle faults; subsequent image log interpretation and whole core description confirmed their existence. Facies analysis from whole core description tied to image log interpretation demonstrates a range of “arid” continental facies across the field, from lacustrine to fluvial to eolian, with paleosols possibly acting as reservoir baffles or barriers. Thin section, SEM, and core plug porosity and permeability data correlated to these environments suggest a strong facies control on reservoir porosity and permeability. Seismic amplitude and impedance data tied to whole core indicate a similar facies influence on the seismic expression of the distribution of reservoir and non-reservoir intervals.
The resultant geological model explains existing gas well drillstem test and production pressure behavior, and demonstrates the necessity for a multi-scalar, multi-disciplinary modeling approach.