ALBERT

Description: 〈p〉The Cretaceous period is renowned for the substantial oil reservoirs that were deposited during the Barremian epoch. The Zubair Formation is typified by sandstones, shales, and siltstones of layers. In the Luhais oil field, the Upper Shale Member has been identified as a source of oil, making it the subject of this research paper, which aims to evaluate the petrophysical properties of Cretaceous reservoirs in the Zubair Formation. The study utilized open-hole log data with thorough quality control of selected open-hole log data, including gamma-ray, caliper, neutron porosity, bulk density, sonic, and resistivity data. Four wells from the Luhais oil field (Lu-07, Lu-08, Lu-38, and Lu-39) were analyzed to evaluate the petrophysical properties. The analysis divided the formation into six main units and corrected formation tops for Upper Shale Member units USM (USM-1A, USM-1B, USM-1C, USM-1D, USM-1E, and USM-1F). To determine the permeability log, the study established a relationship between the quality-controlled Open Hole log and routine core analysis data, including Core Porosity CPOR and Core Permeability KAIR. Two statistical techniques were employed: classical and Multilinear regression. Equations were derived from both methods using core data from Lu-07 and Lu-08. The R-squared value was 0.76 in the classical method and 0.78 in the multilinear regression method. These equations were then used to estimate the permeability log for uncored wells (Lu-38 and Lu-39). The final analysis provided estimations for petrophysical average properties such as shale volume, porosity, fluid saturation, and permeability. The study also identified the net reservoir and net pay, which should facilitate the identification of reservoir and non-reservoir units of the field for future economic planning.〈/p〉