Course Description

• Rock Physics is a key component in oil and gas exploration, development, and production. It combines concepts and principles from geology, geophysics, petrophysics, applied mathematics, and other disciplines. Rock physics provides the empirical relationships, understanding and theory to connect petrophysical, geomechanical and seismic data to the intrinsic properties of rocks, such as mineralogy, porosity, pore shapes, pore fluids, pore pressures, stresses and overall architecture, such as laminations and fractures. Rock physics is needed to optimize all imaging and reservoir characterization solutions based on geophysical data, and to such data to build mechanical earth models for solving geomechanical problems. Attendees will obtain an understanding of the sensitivity of elastic waves in the earth to mineralogy, porosity, pore shapes, pore fluids, pore pressures, stresses, and the anisotropy of the rock fabric resulting from the depositional and stress history of the rock, and how to use this understanding in quantitative interpretation of seismic data and in the construction of mechanical earth models. A variety of applications and real data examples is presented.

Who Should Attend?

• Geoscientists, petrophysicists, and engineers wishing to understand rock physics and learn how to work together in integrated teams to build geomechanical models.

Course Schedule

Day 1

• Introduction
• What is Rock Physics?
• Rock Physics and Petrophysics. What’s the difference?
• Hooke’s law, anisotropy and elastic wave velocities.
• Sedimentary rocks as heterogeneous media.
• The concept of the Representative Elementary Volume (REV) and effective elastic properties.
• Voigt/Reuss and Hashin-Shtrikman bounds.
• Modulus-porosity relations for clean sands.
• Critical porosity and mechanical percolation.
• Gassmann’s equations and fluid substitution.
• Fluid properties and mixtures.

Day 2

• Diagenetic and sorting trends in velocity-porosity data.
• Velocity-porosity models for shaly sands.
• Empirical relations between velocity and porosity, clay content, etc.
• Properties of sand-clay mixtures.
• Velocity-porosity relations for shales.
• Relations between VP and VS.
• Rock compressibilities and relation of 4D seismic to well testing.
• Reflection coefficients and AVO.
• Elastic impedance.
• Rock physics templates.
• Effective medium and effective field theories.
• Velocity-porosity relations for carbonates.

Day 3

• Biot theory.
• Patchy saturation.
• Squirt flow.
• Sediment compaction and the state of stress in the Earth.
• Pore pressure and the concept of effective stress.
• Poroelasticity.
• Application to pore pressure prediction.

Day 4

• Fracture gradient and 3D stress modeling.
• Effect of stress on seismic body waves.
• Third-order elasticity.
• Granular media and discrete element methods.
• Displacement discontinuity methods.
• Stress sensitivity of sandstones.
• Stress sensitivity of shales.
• Stress perturbations around a borehole.
• Determination of velocity variations around a borehole from advanced sonic logging.
• Application to wellbore stability.
• Reservoir geomechanics and stress effects in 4D seismic monitoring .

Day 5

• Fractured reservoirs.
• Hydraulic fracture propagation in presence of natural fractures.
• Seismic characterization of fractured reservoirs.
• Modeling the response of a fractured reservoir.
• Rock physics models for fractures.
• Shales and unconventional reservoirs.
• Anisotropy of shales.
• Rock physics modeling of kerogen in organic-rich shales.
• Effect of anisotropy on AVO.
• Microseismic and effect of azimuthal anisotropy on propagation of hydraulic fractures.