RESERVOIR CHARACTERIZATION USING INTEGRATION OF ROCK PHYSICAL MODELING AND PRE-SATCK SEISMIC INVERSION METHOD, CASE STUDY: CARBONATE RESERVOIR, KUJUNG I FORMATION, “HUMAIRA” FIELD, NORTH EAST JAVA BASIN

• Main Author: Nur Kumalasari, Isti
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/53215
• Institution: Institut Teknologi Bandung

Reservoir characterization in carbonate rocks is more complex because it has various types of pores. To improve accuracy in reservoir characterization we need to integrate all available data and integrate rock physics modelling and seismik inversion method. The inversion method used is EEI and CPEI inversion. The modeling results show that the dominance of the aspect ratio value is 0.17-0.19, so the possibility of the pore type that develops in the Kujung I Formation is the reference pore. The cross plot of elastic parameters that can describe the aspect ratio is Lamda-Rho to porosity. The solution to solve the difficulty of separating the aspect ratio distribution on the Lamda-Rho cross plot against porosity is coordinate rotation. Based on the analysis of well and petrophysical data, it shows that the carbonate layer contains gas at the top of the Kujung I Formation or in high areas (IN-1 and IN-2). In the IN-3 well there is no gas because the well is located in a low area. The most sensitive parameters for separating carbonate reservoirs containing hydrocarbons and not are the Lamda-Rho and poisson ratio. The CPEI inversion results show a good match to the total porosity parameter. Meanwhile, the CPEI inversion results show a good match to water saturation at the top of the formation only. The gaseous carbonate layer has a low CPEI inversion value (Sw <0.54) and is found at slices 2, 10, 16 ms below the Top Kujung I horizon in high areas. The distribution of low Mu-Rho and high CPEI porosity which correlates with high porosity is found on the slice of 2.10.16 ms below the Top Kujung I horizon. The carbonate layer in IN-3 wells is thought to have different facies from IN-1 and IN-2 wells which are characterized by the bell shape of the gamma ray, lower lamda-rho, lower aspect ratio, and the seismic data reflectors are not as strong as in the IN-1 and IN-2 well areas. The possible facies of the IN- 3 well is a back reef lagoon (mudstone-wackstone), while the carbonate facies in the IN-1 and IN-2 well areas is patch reef (wackstone-packstone)