Salinity, pH, and Surfactant Concentration Effects on CO₂-Foam

Abstract

The influence of a number of parameters on CO2-foam stability and surfactant adsorption at reservoir conditions were determined. At 25°C and 1500 psig, using different brine concentrations (NaCl/CaCl2 at 3:1 wt ratio), foam stability was determined to be insensitive to salinity when Chaser CD1045™ (CD) concentrations were > 0.025 wt %. This implied that CD could be used as a stable foam over a wide range of field conditions, but become sensitive to salinity when CD concentration is for example ≥ 0.005 wt %. CO2 foam stability was surfactant concentration-dependent. Coalescence of bubbles is observed only at CD concentration of 0.005 wt %, well below the cmc. Adsorption onto kaolinite increased with surfactant concentration. Adsorption increased with salinity for both NaCl and CaCl2 with the divalent salt system inducing a higher adsorption on the kaolinite. Foam stability was insensitive to salinity when CD concentrations were 0.025 wt % and high, but was sensitive to salinity when CD concentration was 0.005 wt%. Adsorption decreased with pH due to the electrostatic repulsion between bubbles and the grains of rock.

Meeting Name

SPE International Symposium on oilfield Chemistry (2005: Feb. 2-4, The Woodlands, TX)

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

CD1045TM (CD); Kaolinite; Kinetic Stability; Langmuir Adsorption Isotherm, Adsorption; Blowing Agents; Bubble Chambers; Capillary Tubes; Carbon Dioxide; Coalescence; Emulsification; Micelles; PH Effects; Salinity Measurement; Surface Active Agents; Surface Tension, Foams

International Standard Serial Number (ISSN)

1046-1779

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

01 Feb 2005

Link to Full Text

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