PETROPHYSICS Pty Ltd provides petrophysical training and consulting expertise to the oil and gas ind

The ever increasing diversity and abundance of petrophysical data presents choices as to how to best use numerical data and qualitative information in a quantitative petrophysical workflow.  The decision as to which data to use, where and how is usually a subjective process left to the expert.  He/she rarely discusses options with other disciplines and often remains unaware of possibilities. This process of which data to use, where and how should be further examined and formalised with guidelines as to why data is or is not useful.  This thinking does not yet seem to have evolved in companies but is the necessary first step to robust integration.  Much useful data is ignored by petrophysicists.  We must remain eternally vigilant as to the relevance and possible function of new data items in our existing workflows.  Workflows must evolve with new data, that is our task, to use everything at our disposal in the most efficient manner.  Most established workflows today need a complete re-t

Since pore throat size controls saturation and permeability it would seem logical to use saturation or saturation related parameters to predict permeability.  This does not happen in most geological models or even most petrophysical models.  Instead we aquire NMR logs, core analysis flow zones and rock types in attempts to use porosity to address permeability variations whilst ignoring what we already have for a cheaper, more powerful prediction of permeability.  Hydrocarbon pore volume provides a superior default prediction of intergranular rock permeability across different reservoir types and different rock types than porosity, certainly and even saturation.  The fluid zones evaluation should be done first to ensure Sw ~ Swi.  Every petrophysicist knows that good rock contains more hydrocarbon than poor rock at the same capillary pressure (height), but fails to use it! Capillary Pressure Mercury Injection Data (MCIP) for Saturation Height? In addition mercury data generally cannot b