ESTIMATION OF CARBONATE RESERVOIR DISTRIBUTION IN “SUKUNA” FIELD, NORTH EAST JAVA BASIN USING EXTENDED ELASTIC IMPEDANCE AND ELASTIC IMPEDANCE INVERSION METHOD

• Main Author: Rizky Putra, Aulia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/61930
• Institution: Institut Teknologi Bandung

The "SUKUNA" field is one of the oil and gas producing fields located in the North East Java basin. The Kujung formation in this field is composed of carbonate rocks with intercalated shale. This study aims to identify the distribution of porous carbonate reservoirs and the distribution of hydrocarbons laterally in the Kujung Formation. To be able to see the distribution, we need a sensitive elastic parameter and an appropriate seismic method in order to be able to separate the lithology and fluid in the carbonate reservoir. The well that will be used is the TBKY-3 well and the seismic data that will be used are post stack data and partial angle stack data. In this study, the lithology of the carbonate reservoir is separated by elastic parameters, namely mu-rho and the fluid in the carbonate reservoir is separated by acoustic impedance – elastic impedance far parameter. The seismic inversion method that will be used is the Extended Elastic Impedance (EEI) method and the Elastic Impedance (EI) method. The use of the EEI method is carried out through the inversion of the reflectivity volume of the mu-rho parameter. The reflectivity volume will be inverted using colored inversion. Meanwhile, the use of the EI method is carried out through the inversion of the far stack seismic volume. The seismic volume will be inverted using a model based inversion. Then, an analysis will be carried out based on the slicing of the inversion results, isochron, and known geological information. It was found that the porous carbonate rocks located in the high area around the TKBY-2 well, TKBY-3 well, and middle patch reef in this field were a paleo high structure that were exposed to the surface and experienced leaching so that they can become porous, and there are zones in the TKBY-2 well area and middle patch reef which are proven to be filled with hydrocarbons at the top of anticline. However, there is no supporting data that can provide evidence of oil and gas flow in the middle patch reef area, so further tests are needed in this area.