RESERVOIR CHARACTERIZATION IN GABUS FORMATION 'AR' FIELD, NATUNA BARAT BASIN WITH SPECTRAL BALANCING AND ITERATIVE EXTENDED ELASTIC IMPEDANCE INVERSION METHOD

• Main Author: RAHMAN, ALFIAN
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/25340
• Institution: Institut Teknologi Bandung

Gabus Formation which located in Field, West Natuna Basin is one of productive reservoir in Indonesia. Reservoir characterization is needed to get the subsurface image, so the next drilling location can be determined. This formation lithology is shaly sandstone, so an effective method needed to separate sandstone and shale. In this research, reservoir characterization has been done using spectral balancing and iterative Extended Elastic Impedance (EEI) inversion method. <br /> <br /> The purpose of spectral balancing is to balance the amplitude spectrum of partial angle stack data. To separate sandstone and shale as well and to get the zone of good quality reservoir (sandstone with high porosity), an elastic parameter analysis which sensitive to lithology and porosity is needed. Then, ???? angle which has the maximum correlation with the sensitive parameter were calculated. EEI inversion at ???? angle with model-based inversion has been done to seismic data with available log data. After that, iterative inversion is tried to average the one well-model inversion result and extract the sensitive parameter log value at each well. Then invert the seismic again with the model from extracted log data and averaged the inversion result again. This process has been done iteratively. <br /> <br /> The inversion result showed that ????????/???????? parameter is sensitive to lithology and ???????? is sensitive to porosity. Iterative model-based inversion result showed a good result which can make the inversion result better and can separate sandstone and shale as well and also can determine good quality reservoir region.