Publications

The Asri Basin is of rift origin and formed during the early Oligocene, with its axis oriented in a NE-SW direction. The Aryani oil field is located on the northwestern part of Asri Basin. Aryani-1 encountered 10 ft oil pay from 4034 - 4048 ft SSTVD in Lower Zelda formation which is situated 5 - 20 ft above basement. The Aryani basal sand was deposited in a braided channel of alluvial fan environment. Aryani-A1 to Aryani-A8 show net pay from 0 to 27 ft. The purpose of this study is to characterize the Aryani thin layer sand distribution by Spectral Decomposition analysis.Spectral decomposition is a tool for imaging and mapping temporal bed thickness and geological discontinuities. Usually, it provides energy and phase spectra that can delineate temporal reservoir thickness variability and indicate lateral geological discontinuities. Therefore, the spectral decomposition results allow interpreters to quickly and efficiently image and quantify local rock property variability with the 2/3-D seismic data volumes.In this study, spectral decomposition provided a very good characterization of the thin layer reservoir. The basal sand distribution based on an isopach map generated by the high frequency tuning power volumes matched net pay results in 7 wells. Also, the results show other areas with potential for future exploration.Spectral Decomposition is an efficient method for characterizing thin layer reservoirs quickly.