EOR Screening Criteria Revisited – Part 1: Introduction to Screening Criteria and Enhanced Recovery Field Projects

J.J. Taber, F.D. Martin, R.S. Seright – 1997

Abstract

Screening criteria are proposed for all EOR methods based on both field results and oil recovery mechanisms. Data from EOR projects worldwide are examined to identify optimum reservoir and oil characteristics for successful projects. Oil gravity ranges for all current EOR methods are compiled and presented graphically. The current state of the art for all EOR methods is briefly described, with relationships between them noted. Steamflooding remains the dominant EOR method. All chemical flooding activity has declined, but polymers and gels are being used successfully for sweep improvement and water shutoff. Only CO2 flooding activity has increased continuously. Detailed screening criteria tables are provided for chemical (polymer, surfactant, micellar), thermal (steam, hot water, in-situ combustion), gas miscible (CO2, hydrocarbon, N2), and immiscible gas flooding.

Key Takeaways

  • Comprehensive screening criteria tables are provided for all major EOR methods — chemical, thermal, and gas — based on field results and recovery mechanisms, providing a defensible first-pass screening framework for any candidate reservoir.
  • Steamflooding remained the dominant EOR method in 1997, while all chemical flooding activity had declined; only CO2 flooding was growing continuously — a trend that has since reversed significantly for polymer flooding.
  • Polymer flooding is appropriate for light-to-medium oils (above 15° API) in reservoirs above 10 md permeability, with temperatures below 93°C — criteria that exclude many thermal and naturally fractured carbonate reservoirs.
  • The screening criteria are designed as a rapid first filter — not a final economic decision tool — to eliminate clearly unsuitable candidates before expensive reservoir descriptions and economic evaluations.
  • Oil gravity, depth, temperature, permeability, porosity, and remaining oil saturation are identified as the dominant screening variables across all EOR methods — allowing parallel screening of large reservoir portfolios.
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