Publications

The potential of the Talang Akar Formation (TAF) in Krisna High has been established by the presence of 2 productive wells and the results of several tests performed on Krisna High. It has also been confirmed that a mature field exists north of this area with TAF as the main reservoir. However, the development of this reservoir has been hampered by the build-up of the Baturaja Carbonate as main reservoir. Another reason for the TAF reservoir being undeveloped is that available seismic resolution of the reservoir layers are insufficient and qualitative methods such as RMS attributes or even quantitative ones like Acoustic Impedance could lead to misleading interpretations. On the other hand, we have found that color blending spectral decomposition analysis can provide better images. To obtain the best possible image, based on the characteristics of seismic bandwidths in the horizon target, three main frequencies are used, which are 17 Hz, 21 Hz, and 29 Hz. Then, to determine the range of channel width, seismic geomorphology can be justified by implementing log-based empirical equation.

As a result, the area can be described as a fluvio-deltaic channel complex system with a dominant distributary channel and classified as meandering to anastomosing type. The channel distribution in this area has a relatively N-S trending, with some channels having a W-E trend, depending on the position of basement high. Moreover, a meandering main channel was found in the Northeast area where low areas occur and also where a fan system that is probably a channel splay from Krisna High was discovered.

This approach is applicable in areas having 3D seismic data with good acquisition but poor resolution and lacking well data, especially shear wave velocity log (Vs), which makes advanced QI analysis highly limited.