RhoVe Method Empirical Pore Pressure Transform

The rhob-velocity-effective stress (Rho-V-e) method produces a model-driven, stand-alone set of “virtual” rock properties, which at intermediate positions are consistent with Bowers (2001) method default values for the Gulf of Mexico. The RhoVe method uses a single transform to convert both compressional sonic and bulk density to common estimates of effective stress and pore pressure where convergence of the two transformed properties offers a robust solution. Velocity-density conversion functions are mathematically linked to a continuous series of velocity-depth normal compaction trend functions. The calculations are limited by bounding end-member curves that provide a basis for intermediate (fractional) solutions of velocity-effective stress and density-effective stress relationships that are applied to a well of interest. By using the comparative velocity-density functions that match the offset well data in cross-plot, normal effective stress for each end-member and intermediate solutions can be calculated by integrating the discrete velocity-depth profile - now converted to density-depth. The method produces robust solutions as tested on multiple deep water Gulf of Mexico wells, and extends the predictability of high-velocity, low-effective stress rock types such as those found in the Deepwater Gulf of Mexico Wilcox-equivalent Paleogene and older section.