A full update of Lithological, Petrophysical, and Geomechanical evaluation for the Sadi Formation in the Mesopotamia Basin, Southern Iraq

The Sadi Formation in the Mesopotamia Basin is part of the Santonian-Campanian interval. This study was conducted to update the lithology, petrophysical, and geomechanical characteristics in four southern Iraqi fields with the new exploration data using data from 21 wells in the Mesopotamia basin, which represent the Sadi formation in the Zubair, Rumaila, Majnoon, and West Qurna/1 fields. The results indicated that the maximum horizontal stress azimuth should be 55 and 318 degrees toward the northeast, and the fault system type is Normal. The lithology consists mainly of limestone, with a low percentage of Dolomite and sandstone, and some Shale content. Hydrocarbon potential in the Sadi Formation in the West Qurna/1 Field will increase as wells are drilled toward the south, and the northeastern part of the field has gas potential (condensate gas). Only the Rafdiya dome in the Zubair Field could contain hydrocarbons. On the other hand, there is no hydrocarbon potential for the Safwan dome or those on the west flank, and no hydrocarbon potential in the Rumaila Field except on the east side. The hydrocarbons in the southern part of the Majnoon field are more likely and will decrease toward the north. Future work must focus on the flanks of the Sadi Formation in the Majnoon field, drilling more wells east of the crest (possibly on the east flank), and in the West Qurna/1 Field in the south to discover more about the Sadi Formation in this area. Net pay thickness in formations that potentially contain hydrocarbons ranges from 5.6 meters in the West Qurna oilfield to about 79 meters in the Zubair oilfield, with average porosities of 14.5% and 15.8%, and a high water saturation in most fields.