Publications

Amplitude variation with offset (AVO) analysis certainly proved to be useful tool, not only for hydrocarbon reservoirs detection, but also for basic reservoir characterization and, more recently, for reservoir monitoring. In this study, we applied the AVO analysis to detect the existence and distribution of the methane gas embedded in the coal, which commonly called Coal Bed Methane (CBM). In AVO, the reflection coefficients at the target horizon (such as the top or the bottom of a hydrocarbon reservoir) are the fundamental quantities to be analyzed as function of offset. Therefore in order to characterize the complete reservoir including the body of the layer, we combined the AVO technique with the Elastic Impedance (EI) inversion. The EI inversion is dedicated to provide the elastic parameter such as Poissons ratio, (s), Lambda-rho (??) and Mu-rho (µ?), which is believed to be able to enhance the level of thrust in interpretation.The results show that AVO analysis can be used to provide the early indication of CBM existence, which is indicated by the AVO anomalous (i.e. increasing amplitude with increasing offset) at the top of CBM. This indication has a good match with the inversion result, which is illustrated by the pattern of CBM distribution and cross plot of of µ? vs ??, s vs ??, and s vs µ?.Key words: AVO Analysis, EI inversion, CBM