Petrographic, Petrophysics and Seismic integration: Reshadat Oil Field in the Persian Gulf an Approach to Characterize Mishrif Reservoir on

Reshadat Oilfield is an anticline with an approximately North- South trend. The Upper Sarvak Formation is a potential reservoir in this area. Mishrif Reservoir in this field has been divided into five zones. Zone A, (the uppermost) is recognized as the best reservoir zone. Diagenetic processes including (dissolution, dolomitization and fracturing) improved reservoir qualities. As a result of diagenetic process (dissolution), stratighraphic trap (diagenetic) has been created, and zones A and B are shaped into pinch out trap. Weathering dramatically improves the reservoir permeability and thus controls the extent of this diagenetic trap. Investigation shows that local unconformity in the southern flank of Reshadat oilfield, created the highest reservoir zones in this part. Consequently; reservoir quality of zones C and D have been improved. The inversion of the seismic data to acoustic impedance has allowed for better definition of the main lithological units. The inverted impedance clearly highlights facies and porosity variations within Mishrif interval which not apparent on seismic data. Depth conversion has been performed and accurately ties the interpreted horizons to the available well data. The combination of seismic interpretation and seismic inversion has improved our understanding and definition of the Mishrif reservoir. Applying reasonable cutoffs for porosity and permeability, reveals valuable zones (A&B) in this portion of the field. These zones are located in west and northwest of Reshadat Oil Field.The study shows that thickness of valuable zones are increasing towards the west and the northwest and decreasing in the center and south of the field.