Integrated 2D seismic interpretation and 3D geological modeling for reservoir characterization of the upper Cretaceous Formations in the Silah field, Egypt

A comprehensive geophysical interpretation was applied to investigate the subsurface structural features and recognize the promising hydrocarbon zones in the Silah reservoir rocks. The study looks closely at the subsurface geological features that control oil accumulation. This helps us figure out where to drill and how to develop reservoirs. These objectives were achieved using well logging, 2D seismic interpretation, and 3D geological modeling. This was accomplished by creating a synthetic seismogram and using vertical seismic profiling (VSP). Different maps, cross-sections, and 3D structural models were constructed to visualize the subsurface structural configuration and architecture of the Silah Field. A calibration process between sonic logs and the velocity of the existing VSP data was carried out to produce a more accurate and detailed time-depth relationship at the well location. All information deduced from TWTs, seismic-structure depth, isochore maps, and depth-structural cross-section was used to identify and determine the locations of the depocenter and the shoulder of the basin. The study area is characterized by a complex fault pattern and trend. The structure features were due to an extensional rift stress followed by a compressional force. The resulting depth structural map displays several NW-SE and NE-SW normal faults along with a master E-W to ENE fault direction on top of the Early Cenomanian Abu Roash (F) and (G). These normal faults extended to the Khoman Formation. The extensional faults formed grabens and half grabens structures in the north and northwest portions of the study area. The compressional stress event created folding and fold-related fault structures in the central part of the study area. The depocenter area is present in the NW portion of the study area at a depth reaching 8000 ft. The structural elements, such as fault-bounded closures and half-graben systems, act as primary petroleum traps, influencing reservoir connectivity and fluid migration pathways. The findings indicate that further exploratory wells should be drilled in the Silah area to boost production from the carbonates and sandstones of the Abu Roash reservoir. Other promising oil-bearing zones within the area under investigation could also be proposed.