Petrophysical Characteristics of Mishrif Formation in Q Oil Field, Southern Iraq

This research aims to evaluate the quality of the Mishrif Reservoir in the Q Oilfield by analyzing limited data using modern techniques. The Mishrif Formation consists of limestone, dolomite, and shale. The reservoir is divided into two units, A and B. Data were obtained from the wireline logs, which include caliper, gamma ray, density, neutron, resistivity deep, and resistivity shallow logs, for three wells. The petrophysical characteristics were computed using the well-log evaluation technique. The results indicated that the shale volume ranges between 18.3% to 11.1%, the total porosity ranges between 16.4% to 6.6%, the effective porosity ranges between 14.6% to 3.8%, the permeability ranges between 2020.465468 to 15.623 mD, the water saturation ranges between 51.5% to 16.7%, the hydrocarbon saturation ranges between 83.3% to 48.5%, the water mass volume ranges between 11.3% to 3.4%, the net pay thickness ranges between 91.67 to 1.32 m, the oil content ranges between 12.7% to 1.8%, and the moveable oil ranges between 1.4% to 0.8%. The results revealed that the Mishrif Formation possesses favorable reservoir properties and substantial net pay thickness. The zones of excellent quality are evidenced by a porosity of 15%, permeability surpassing 2000 mD, and net pay over 90 m, affirming the presence of prolific reservoir facies. The lower unit B has superior reservoir characteristics and quality than the upper unit A.