Publications

The “S” Field is mature oil field operated by “P” Asset V. The Reservoir in this field, multi-layered shaly-sands with depositional environment, is deltaic-shallow marine during the Middle to Late Miocene period. However, with the decrease in the oil price, drilling of development wells is hard to justify. Re-evaluation of logging data, especially the low resistivity zone, is seen as the best strategy to apply. The “S” Field contains more than 200 wells. Oil Base Mud was used starting from the middle of 2003 because clay has a sensitivity for swelling. The low resistivity study in this paper determines clay mineral and conductivity mineral through petrography analysis, X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM) on Side Well Coring sampling, and also determines drilling mud characteristics to identify low resistivity problems. Based on XRD and SEM analysis, the presence of clay minerals is dominated by kaolinite and some illite. Petrography analysis shows the presence of pyrite and siderite in small quantities. The main problem is caused by reservoir characteristics and the influence of drilling mud (lignosulfonate). These characteristics are explained in full in this paper.