Publications

Direct Hydrocarbon Indicators (DHI) is commonly analyzed using the Amplitude Versus Offset (AVO) method. The latest analytical method developed for DHI identification is Velocity Variation with Offset (VVO) or Angle (VVA) to identify gas clastic reservoirs within the background lithology. A new attribute of VVO or VVA method is Root Mean Square (RMS) velocity gradient which provides a tool to distinguish hydrocarbon charged reservoir from brine reservoir. RMS Velocity field is main driver of VVO or VVA. It is generated automatically from Normal Move Out (NMO) corrected gathers. Transforming amplitude data to velocity data from the nearest offset to the far offset in Common Mid Point (CMP) gathers produce offset-dependent RMS velocity. Computation of RMS Velocity along offset is run to derive velocity gradient. The VVO or VVA method is tested in clastic reservoirs in South Sumatra area. VVO has identified DHI anomalies based on offset velocity analysis. Combining the VVO based DHI anomalies with sonic gradient data from known wells is used to high grade anomalies which related to high pore pressure. Keywords: DHI, AVO, VVO, velocity gradient, sonic gradient, high pore pressure, South Sumatra.