Integrating Measured Kerogen Properties With Log Analysis for Petrophysics and Geomechanics in Unconventional Resources

摘要

Workflows for log analysis in conventional reservoir rocks are difficult to apply in organic-rich mudrocks due to the presence of abundant kerogen (solid, insoluble organic matter). There are two key reasons for this difficulty. First, kerogen is part of the solid matrix but responds like a fluid in traditional porosity log analysis (e.g., density, neutron). Accurately estimating formation volumes from logs, therefore, requires a method to separate the kerogen and fluid signals in the matrix and porosity, respectively. A second difficulty is that the petrophysical properties of kerogen (such as its density and hydrogen index) vary by more than 50% relative, impacted by geologic forces including maturation, and are rarely known. No logging tools can measure kerogen properties directly.