INTEGRATED INTERPRETATION FROM THE RESULT OF TDEM INVERSION USING OTHER GEOPHYISICAL DATA IN GUNDIH FIELD, CENTRAL JAVA

• Main Author: Aji, Waskito
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45589
• Institution: Institut Teknologi Bandung

The time domain electromagnetic (TDEM) method is one of the electromagnetic methods in geophysics. The TDEM method uses the phenomenon of electromagnetic waves propagating to characterize conditions under the earth's surface. The TDEM method can be applied in various fields that discuss structures in oil and gas exploration, groundwater exploration, to geothermal exploration. In this study, the TDEM method was implemented in the oil field in Cepu, East Java which will be used as a place for carbon capture and storage projects (CCS). The TDEM method will be used to identify the reservoir zone as the place for injection of in the CCS project. Non-linear inversion is applied to TDEM data to get the resistivity structure. The author uses the differential evolution inversion method to inverse TDEM data. The differential evolution inversion method is a global search population – based technique. The advantage of using global inversion population-based techniques is that they are able to explore better model space because they directly try out several potential models at once. The implication is by using differential evolution we can find solutions that are not easily trapped at local minimums. When inversion is applied to the field data of Gundih Field, the results obtained are able to identify 3 successive zones of succession from the top to bottom, namely the relatively high resistivity zone, the relatively low resistivity zone, and the relatively high resistivity zone. Then, the result of other geophysical survey is integrated in the proccess of analysis and interpretation. Based on the integrated interpretation, we can identify some of rock formations beneath survey area. Every formation has inhomogenous resistivity that may caused by the inhomogenous lithology in every rock formations