Rock Physics: Seismic Reflections of Rock Properties

Dr. Jack Dvorkin

Participants will learn the uses of rock physics in interpreting the elastic properties of earth, as sensed by seismic reflections, for lithology, fluid, and porosity determination. Presented are the basics of rock physics as well as applications of rock physics at various scales – from pore to core to reservoir. Discussed are new cases studies concerning seismic-based porosity and fluid determination in clastics and carbonates. Also, presented are new developments in rock physics of gas shale. A special section is dedicated to digital rock physics and its relevance at wireline and reservoir scales.

Duration

16 hours

Intended Audience

Intermediate level geoscientists and petroleum engineers

Prerequisites (Knowledge/Experience/Education Required)

At least a B.Sc. in Geosciences and/or Petroleum Engineering. Basic knowledge of principles of reflection seismology, geology, elasticity, fluid mechanics, and mathematics.

Course Outline

  1. Basics of Rock Physics
    • Purpose of Rock Physics. Practical use of rock physics transforms in seismic interpretation
    • Definitions and methods of rock physics. Elasticity, fluid flow, electrical properties
    • Effects of pore fluid on rock’s elastic properties; fluid substitution; importance of the Vp/Vs and Poisson’s ratio; effects of spatial fluid distribution and frequency
    • Effects of porosity, mineralogy, and texture on the elastic properties of sediments
    • Effects of diagenesis and cementation
  2. Applications of Rock Physics
    • Theoretical models of rock physics
    • Rock physics diagnostics based on wireline data
  3. Case Studies
    • Unconsolidated sediments.
    • Tight gas sandstones.
    • Carbonates
    • Gas shale
  4. Effects of Scales of Observations and Experiments on Interpretation
  5. Digital Rock Physics
    • Elasticity
    • Permeability
    • Electrical properties

Learner Outcomes

  • Determine the level of rock physics required for a specific prospect evaluation. Are simple well-data-based cross-plots enough, or is involved mathematical rock physics modeling in order?
  • Use simple ways of producing synthetic seismic signatures of reservoir and non-reservoir rocks for “what-if” scenarios for specific lithology, pore fluid, and geological settings
  • Handle methods of fluid substitution and quantify their relevance to the task at hand: prospect evaluation or production monitoring
  • Recognize various rock physics models that relate the elastic properties to porosity, lithology, and diagenetic history. Find an appropriate model for a specific project
  • Conduct rock physics diagnostics (i.e., establish a rock physics transform) based on well or laboratory data and consistent with geology

Instructor Biography

Jack Dvorkin