... incomplete suites of logs. In VICO, the improvement in the subsurface analytical methods has proven successful in helping identify additional reservoir opportunities. Recently, a method has been developed to identify "bypassed gas zones" in shallow reservoirs. This method uses the sonic log as the main tool...

... region. Despite following the program however, the drilling experienced significant challenges, particularly in the shales where the sonic logs have shown high velocity and therefore high rock strength. To investigate the root cause, several mechanisms for the wellbore instabilities have been...

... and the difference between the shear and compressional sonic porosities. The fracture porosity estimates were cross-checked against the image log analysis completed. Owing to washouts across the most heavily fractured intervals, it was expected that fracture porosities from the density and compressional sonic logs...

... condition has rarely been considered as a parameter in conventional velocity porosity transforms. Reservoir pressure reduction, resulting from hydrocarbon production, increases effective stress. Consequently for a given reservoir rock at a given depth and porosity the sonic log may show decreasing values...