The Strength of Surface Seismic Attributes as a Quick Tool for the Dolomitization Detection in Alamein Carbonate Reservoir, Khepri Field, Shushan Basin, North Western Desert, Egypt

Abstract Khepri deep Field was discovered in 2020 by drilling the exploratory well KPR-D-1 which encountered 59 feet net pay in the Alamein dolomite reservoir and tested 4000 BOPD. The Alamein formation is recognized as a very good carbonate reservoir in this field with up to 4 million barrels of oil were produced there. Core analyses revealed that the reservoir attains up 15% vuggy porosity with about 20% residual oil saturation. Initial volumetric calculations were 7 MMSTB of original oil in place that increased to 10 MMSTB, where the Alamein structure elevated by about 50 feet. In order to understand any lateral changes related to subsurface geology, surface attributes have numerous applications in both structural and stratigraphic aspects. These applications depend on the extraction of data or information regarding amplitude, frequency, and phase from seismic data across a selected surface that represented the reservoir or between two surfaces. The main risk in this case is the dolomitization process; when dolomite is found in our wells at an appropriate structural level, oil is found as well. The density of limestone is higher than that of dolomite. Due to the fact that the secondary porosity produced by the dolomitization process lowers density, which in turn lowers seismic wave velocity. The important thing to remember is that dolomite, unlike limestone, is supposed to have a lower amplitude value and acoustic impedance. Our reservoir's seismic interpretation has been completed, and additional top and base surfaces have been made so that it can apply a variety of seismic properties through this zone in order to capture any events. Anomalies can be seen in some places and surrounding the main fault according to the minimum amplitude, average strength, sweetness, and RMS qualities. Thankfully, our data for lithological interpretation of dolomite from wells matches these abnormalities.