Fluid Identification in Carbonate Stringer Reservoirs: A Modeling Study from Oman

Abstract

Carbonate stringers are self-charging reservoirs residing inside salt structures and known for their challenging characterization and fluid identification. We build a geological model that conceptualizes stringers in some fields from south Oman Salt Basin. We use the model to produce P-wave and S-wave velocity, and density models. The models are used to create pre-stack gathers from which AVO attributes are extracted. The gathers are inverted back to impedances and density models using pseudo-well logs that are created from the input models. The AVO analysis demonstrated that AVO attributes may not be able to detect the carbonate reservoirs because of the increase of Vp/Vs from the Ara salt to the reservoir rock. However, the post-stack and pre-stack inversion results suggested that the reservoirs can be detected using different elastic products, namely Vp/Vs, Poisson ratio, bulk modulus, and Lambda Rho among other impedance-based fluid indicator. The result from the study will be used for the interpretation of a new seismic data which is acquired in the area.