Seismic attributes are used to characterize reservoirs in terms of lithology, porosity and fluid properties. However, interpreting full-stack seismic based attributes for gas saturation has limitations especially in settings where low-saturation gas, also called paleo-residual gas (PRG), is present. The seismic amplitudes related to full saturation gas and PRG are so similar it is difficult to distinguish the two. One such geologic setting in which this occurs, is the Columbus Basin, offshore Trinidad. We present a seismic analysis study from Trinidad to reduce the risk associated with PRG. The seismic analysis included a rock physics analysis to understand the seismic sensitivity to various rock properties, seismic data conditioning to improve the AVO well-tie, pre-stack inversion to estimate velocities and density, and frequency decomposition to study subtle changes in the waveform. We concluded with an integration of the various models to reduce uncertainty in prediction of PRG zones. We were able to use seismic analysis to successfully improve our prediction of PRG compared to using only conventional seismic attributes (full stack seismic, fluid impedance).
Presentation Date: Monday, October 12, 2020
Session Start Time: 1:50 PM
Presentation Time: 3:55 PM
Location: 361A
Presentation Type: Oral
