Integrated Seismic Attributes and Spectral Decomposition for Reservoir Characterization Apollonia Formation Northwest Abu El-Gharadig Basin, Egypt

This paper attempts optimum utilization of studied field resources by evaluating the previously under-explored unconventional Apollonia chalky carbonate reservoir petrophysically characterized very high drilling gas readings while the deep resistivity maximum 3 ohm due to the content of irreducible water very high ranges from 40-80% based on core data generally our reservoir petrophysically characterized by high porosity between 12-45% with average 32% and very low permeability maximum 1.5 mD that need further stimulation operations (acidizing and hydraulic fracturing). This work discussed the structural pattern and fault distribution of the study area to understand the tectonic framework that controlled the Apollonia-A Formation. Several normal faults had been unravelled through seismic data interpretation that influenced the geometry and compartmentalization of the studied reservoir. In this respect, seismic attributes and spectral decomposition techniques were integrated to enhance subsurface interpretation, presenting reliable tools for reservoir characterization. Amplitude, coherence, and curvature seismic attributes have been applied for delineating structural and stratigraphic features, while spectral decomposition allowed for the identification of thin beds and frequency anomalies related to gas-bearing zones. Integration of the above techniques provided a detailed and high-resolution view of the reservoir architecture and heterogeneity. The results highlighted the distribution of gas anomalies and lateral continuity of the reservoir across Apollonia-A Formation, which helped the identification of potential gas-rich zones and an increase in confidence in the delineation of the productive intervals for further exploration and development