Publications

A new attribute energy-weighted AVO (EAVO) is one of the derived attributes of AVO which is often used as an indicator of the presence of hydrocarbons and can be applied to pre-stack and post-stack seismic data. The main principle of this attribute is to increase the anomalous response associated with hydrocarbons while attenuating the seismic background around the anomaly. These advantages are not found in other types of attributes where almost all of them can only be used on one type of seismic data. This study aim to compare the results of EAVO analysis with AVO on pre-stack and post-stack seismic data in determining the distribution of hydrocarbons in the Acacia Bagus structure, Jatibarang Field, North West Java Basin. Pre-stack, post-stack, and Well A-01 seismic data are the data used in this study. First of all, a quick look interpretation of the well data is carried out to determine the target zone. After that, pre-conditioning gather, well seismic tie, horizon picking, EAVO analysis and AVO class analysis are carried out. Afterwards, the seismic data is divided into 3 different angle ranges (near-stack, mid-stack, and far-stack) to see the target response at each AVO and EAVO volume. Two targets are found in Layer F, Upper Cibulakan (target A) and Upper Baturaja Layer (target B) both with limestone lithologies. Both targets are classified as AVO class I, which is a high impedance sand relative to the shale that covers it. The target is the top gas-saturated carbonate reservoir because the intercept vs gradient cross plot results are in quadrant IV which is far from the water trend. For target A, the dimming response accompanied by polarity reversal in the far-stack data is clearly visible in the AVO volume. While, the EAVO volume only shows dimming. For target B, the dimming pattern is clearly visible on each AVO and EAVO volume.