RESISTIVITY AND SALINITY ANOMALY IN LOWER KUTAI BASIN AND IT’S IMPLICATION TO OVERPRESSURE ESTIMATION

• Main Author: PRAMUDITO (NIM : 22712301); Pembimbing : Agus Mochamad Ramdhan, Ph.D, ADHI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/19796
• Institution: Institut Teknologi Bandung

The study about overpressure in Lower Kutai Basin has been done by Ramdhan (2010), From the study, there is some anomaly noted in the shallow section of the basin. The anomaly is quite interesting because it looks constant in almost all well in Lower Kutai Basin. <br /> <br /> For the purpose to knowing about the cause of the anomaly, several well logging data have been processed to produce the formation water resistivity and salinity. The data processing is dividing into two main part, sand shale discrimination and resistivity and salinity analysis. The method which used in this research was Kevi method and Raiga method to determine porosity which will be involved into Kevi method calculation. <br /> <br /> The higher formation water resistivity in shallow section is affected by circulation of meteoric water which has lower conductivity value than normal formation water and interpreted as bicarbonat water. Horizontally, the effect of the circulated meteoric bicarbonat water is decrease to seaward / external axis. The lower salinity content in overpressure zone probably caused by diagenetic of smectite into illite. The effect of hydrodynamic movement from deeper part caused by the different of overpressure may also decrease the salinity.