Petrophysics and Geophysics Relevant to CO2 Enhanced Oil Recovery

William Harbert

In this SEG course the basic physics relevant to CO2 are presented, including the descriptions of gas, liquid and super critical phases (scCO2).

Enhanced oil recovery (EOR) was a natural development in the production of hydrocarbons. In this course topics relevant to the utilization of CO2 to enhance oil recovery are presented. CO2 is an especially appealing EOR injection agent. In this SEG course the basic physics relevant to CO2 are presented, including the descriptions of gas, liquid and super critical phases (scCO2). EOR-CO2 sites will be reviewed with respect to monitoring technologies. In addition to EOR-CO2, in several sites, natural production of hydrocarbons contains a significant proportion of CO2, which is separated and then reinjected into other formations, or the producing formation (for example, to maintain formation pressure). Successful methods of geophysical monitoring of these injections will also be reviewed and summarized. The scCO2 phase is a material state in which there is no surface tension, somewhat like a gaseous state; scCO2 has an approximately fluid density and can diffuse through material and fluids, interacting with them. Surprisingly scCO2 is commonly used to extract essences from fruits, coffee beans and oil from the ground!

This SEG course is then extended to a description of the physical properties of CO2, stability ranges, and moduli. These are then related to geophysical methods that have been used successfully to monitor, verify, and account for subsurface EOR-CO2 in geophysical studies. Successful geophysical monitoring technologies reviewed include microgravity, electromagnetic, satellite based surface deformation monitoring, 3D and 4D reflection seismic based methods, vertical seismic profiling (VSP). At the conclusion of the course the participant should have an solid understanding and introduction to the material properties of scCO2, petrophysical changes expected from the presence of CO2 as a pore filling phase in the subsurface, the scale of EOR-CO2, and a thorough review of geophysical methods that have been successfully applied to monitoring subsurface CO2.


8 Hours

Intended Audience

Entry Level

Knowledge/Experience/Education Required

The course is designed to be followed by anyone with a broad geoscience background: no specific detailed fore-knowledge is required, although a familiarity with geophysical, exploration and drilling terminology will be useful.

Course Outline

  • General overview of physics relevant to subsurface CO2 monitoring and EOR
  • Basic physics of the CO2 specifically.  Gas, Liquid, and super critical phases.
  • Common EOR sweep strategies and topologies
  • Geophysical Methods (Method/Principles/Physical Properties and Physics/Interpreted Outcomes).
    • Electromagnetic Monitoring
    • Surface monitoring
    • Crosswell monitoring
    • Micro Gravity Monitoring
    • Deformation Monitoring
      • InSAR
      • Tilt array monitoring
    • Seismic
      • 3D/4D
      • VSP / Crosswell
    • Microseismic
    • Airborne CO2 detection
  • Case Histories
  • Summary and Conclusions
  • Bibliography and References
  • Data Tables

Learner Outcomes

  • Understand the physics relevant to CO2 and its phases.  Understand what supercritical CO2 is and why it is used in EOR.  Understand basic injector/producer geometries used in EOR.
  • Identify the physics and petrophysics relevant to CO2 detection in all geophysical methods.  Understand the ambiguities and potential pitfalls of the various geophysical methods applied to CO2 monitoring and EOR.  
  • Review the importance of a thorough understanding of fracture, fracture geometries and the importance of these data to EOR sweep efficiency.
  • Recognize the methods previously used, and know from direct review of geophysical interpretations, for CO2 subsurface imaging and monitoring.
  • Estimate the most useful geophysical techniques relevant to a variety of potential scenarios at hypothetical CO2 monitoring and EOR sites.

Instructor Biography

William Harbert