Geological Interpretations of Vertical Effective Stress-Compressional Sonic Transit Time Cross-plots for Pore Pressure Prediction

Abstract

Relationships between vertical effective stress (VES) and compressional sonic transit time (Δt) are widely used in the petroleum industry to predict pore pressures to ensure safe drilling operations and robust well designs. Whilst on most occasions trends can be established on VES-Δt plots to model mudrock pore pressures, there are increasingly more frequent examples where VES-Δt plots contain highly scattered data for which simple trends are difficult to establish.