Analysis of the Hidrocarbon Sandstone Distribution Using Rock Physics and Petrophysic Calculations, Simultaneous Inversion, Extended Elastic Impedance (EEI) and Curved Pseudo-Elastic Impedance (CPEI) in X Field Bonaparte Basin

To analyze the distribution of hydrocarbon reservoirs in an area, appropriate methods and parameters can be used to map sediments in the area. In this study, the research was conducted on the X Field located in the Bonaparte Basin. The EEI and CPEI methods are used. The Extended Elastic Impedance (EEI) method is a method that can be used to connect seismic data with elastic parameters by applying the principle of angular rotation. From this method, seismic volumes of various elastic parameters and reservoir parameters will be obtained. The Curved Pseudo-elastic Impedance (CPEI which is able to answer the problem in describing the distribution of fluid in the study area) is also carried out. Gamma Ray (GR) is used to detect lithology and fluid distribution, while from the results of CPEI inversion, the water saturation volume is obtained to see the hydrocarbon distribution in the study area. The results show that the two inversions are able to differentiate the distribution of tight sand lithology, shale, wet sand, gas sand and porous sand. The presence of gas sand distribution can be identified by the value of GR = 20-40 API, λρ = 0-50 GPA*gr/cc, μρ > 80 GPA*g/cc, σ = 0.05-0.24 unitless and the value of Sw = 0-40%, lithology tight sand has a value of GR = 40-70 API, λρ = 70-80 GPA*gr/cc, σ>0.4 unitless, shale lithology has a value of GR > 90 API , μρ <30 GPA*gr/cc, and wet sand is shown with the value GR = 20-40 API, λρ = 50-80 GPA*gr/cc, σ = 0.25-0.35 unitless and Sw> 70%. Based on the results of these interpretations, a sandstone distribution map in X Field was generated and it consists of 2 reservoir layers in the research target zone.