LITHO CURVED PSEUDO ELASTIC IMPEDANCE (LCPEI) AND STOCHASTIC SEISMIC INVERSION FOR ESTIMATING HYDROCARBON PORE VOLUME OF THE CARBONATE RESERVOIR IN KUJUNG FORMATION

• Main Author: Farras Farhan, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68871
• Institution: Institut Teknologi Bandung

Carbonate is the largest potential hydrocarbon reserve both in Indonesia and in the world, yet it is an exploration challenge because the complexity of the carbonate pore system itself is not easy to analyze quantitatively. The uncertainty aspect of the modeling results and the interpretation of elastic parameters is also a topic that has not been widely studied in Indonesia. In this study, the carbonate reservoir pore volume in Kujung Formation, North-East Java Basin, was carried out using a trigonometry approach litho-curved pseudo elastic impedance (LCPEI) attribute in rock physics log data and Bayesian framework in stochastic seismic inversion. From the well log data analysis, the fluid content and porosity in the Kujung Formation can be delineated based on the elastic parameter ???????? to ????????/???????? with curved pseudo elastic impedance (CPEI) and LCPEI attribute. The LCPEI attribute is capable to mimic porosity better than density alone because it would not be affected by fluid. This combination of 2 attributes would produce a delineation of hydrocarbon-bearing pores in the ???????? to ????????/ ???????? cross-plot. In this study, the CPEI and LCPEI approaches were applied to fit the differential effective medium (DEM) rock physics model that model the fluid content and porosity of carbonate rocks from rock physics parameters. Afterward, the approach was improved through the automation process to determine a better correlation to the petrophysical logs. The LCPEI correlates 75% to its effective porosity log in the Kujung-1 formation. The rock physics information in the reference well was then used as a reference for lateral distribution where the acoustic impedance volume and ????????/???????? were obtained from stochastic inversion of the prestack angle gather seismic data. Afterward, by applying the cut-off and the correct scaling to the petrophysical log (water saturation log and porosity log), the volume of Sw-equivalent from CPEI and porosity-equivalent from LCPEI could be obtained. Finally, the estimation of hydrocarbon pore volume can also be generated and calculated volumetrically.