APPLICATION OF SEISMIC ATTRIBUTES, AI POST-STACK INVERSION, AND GEOSTATISTICAL METHODS TO ESTIMATE SHALY-SAND RESERVOIR POROSITY IN THE BNR FIELD, CENTRAL SUMATRA BASIN

• Main Author: Shalshabilla, Johana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77665
• Institution: Institut Teknologi Bandung

The BNR field is one of the development phase fields in the Central Sumatra Basin. In this field, the Duri Formation acts as a reservoir rock. The Duri Formation lithology is medium sized sandstone interspersed with shale. Based on drilling activities that have been carried out, shaly-sand in the Duri Formation was found to have quite high heterogeneity with uneven sandstone quality. In the same anticline and closure structure, it was found that there were variations in the quality of the sandstone laterally and vertically. The challenge in conducting characterization in this field is the limited seismic data available. Where there is only post-stack seismic data. Based on the results of parameter sensitivity analysis in this field, the parameter that can separate reservoir and non-reservoir data is shown by the Vp/Vs parameter. Meanwhile, to obtain Vp/Vs inversion, pre-stack seismic data is needed. Therefore, this research will focus on reservoir characterization using the seismic attribute, post-stack Acoustic Impedance (AI) inversion, spectral decomposition, and geostatistics approach with the expected output in the form of mapping the estimated porosity distribution of the Duri Formation shaly-sand reservoir in the BNR Field. Based on the porosity estimation map obtained, it was observed that the porosity in the BNR Field is more controlled by the sedimentation facies in the field. In the D2150 horizon, a shaly-sand reservoir is observed that has good porosity (20%-27%) associated with the tidal bar sand facies, especially in the southern closure. Meanwhile, the D2300 horizon is related to the tidal sand bar and sand flat facies that exist in both the northern and southern closures. Based on the maps obtained, three proposed well locations can be proposed