Reservoir Evaluation of the Sa’di and Khasib Formations in Q Field, Southern Iraq

The petrophysical characteristics of the Late Cretaceous Sa’di and Khasib formations were investigated in the Q oilfield, southern Iraq. Well log data from four wells across zones QA and QB were utilized in this study. The well log data were subsequently analyzed using the advanced Techlog Quanti module to interpret the well log data in terms of computer-processed interpretation and cross-plot analysis for studying rock types, porosity, permeability, and hydrocarbon saturation. The objectives were to identify zones with favorable petrophysical characteristics, measure their dispersion, and compare them well to well to improve reservoir management. The results showed a contrast between the two formations. The Khasib Formation, comprising limestone and dolomitic limestone, exhibits comparable characteristics across wells, including greater porosity (7-17%) and more continuous hydrocarbon zones than the Sa’di Formation. The Sa’di Formation is composed of a variety of rocks, including different shale percentages in the upper and lower portions, resulting in varied porosity (4-13%) and permeability. The bottom section of the Sa’di Formation, represented by wells QA1 and QA2, has a significant oil content and thickness. The statistical analysis revealed that the wells in the southwestern field (Group A) have superior reservoir attributes, notably the Sa’di Formation, which has little shale and high porosity. The results indicate that the Khasib Formation is a more dependable hydrocarbon source across the Q field, whereas the lower Sa’di Formation has a strong local production potential. The study of rock types, shale content, and properties helps in targeting exploration and better production strategies in the Q oilfield and similar areas of the Mesopotamian Basin.