CARBONATE RESERVOIR CHARACTERIZATION USING PSEUDODENSITY APPROACH IN AVO INVERSION METHOD QALBI FIELD, KUJUNG FORMATION NORTH EAST JAVA BASIN

• Main Author: (NIM: 22314017), MINARTI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23079
• Institution: Institut Teknologi Bandung

Based on data from World Energy Outlook, 60% of world’s oil and 40% of the world's gas is in carbonate reservoir, including in Indonesia some carbonate reservoir has proven to be a very potential field, such as Kujung formation in North East Java basin. The heterogeneity of geometry, pore system, mineralogy, and fluid saturation effects on carbonates rises uncertainties in reservoir characterization. Reservoir characterization describes spatial distribution of petrophysical parameter, such as porosity & saturation. In this research, main data input is partial stack seismic volume with well data as constraint, pseudodensity approach used to determine porosity that related to sensitive parameter analysis, which is used logarithmic of Mu-Rho. An algorithm of Full Offset Approximation was applied to extract reflectivities in the AVO inversion, it can quantify the elastic parameters associated with pore change, and gas saturation more accurately. In this study results, AVO inversion shows the optimal correlation either AI (0.914) or SI (0,899). Map slice analysis was used to describe lateral distribution of this carbonate reservoir properties, it shows the appropriate high closure at the center of the study area, which characterizes the isolated platform, and the poros zone with low acoustic impedance (low-AI) indicates gas saturated zone, which dominantly develops in the southwest (SW) - northeast (NE) direction.