CO2 Foam for Heavy Oil Recovery: Stabilization of CO2 Foam by Nanoparticle and Polymer

• Author / Creator

  Jia, Daimeng

• Due to unsatisfactory sweep efficiency of gas injection, foams, CO2 foams in particular, are utilized to reduce residual oil saturation. Conventionally, generation and stabilization of CO2 foams are achieved by surfactants. However, foams, stabilized via this traditional method, tend to sustain undesirable stabil¬ity with relatively short term under reservoir conditions. Because of their outstanding stability, nanoparticles can be used to mitigate such weakness. Moreover, a viscosifying polymer is used along with surfactant and na-noparticle to stabilize the foam. However, the challenge is to understand how the combi-nation of surfactant, polymer, and nanoparticles improve the performance of conventional foam for heavy oil recovery. In this thesis, a new type of foam generated with Surfactant, Polymer, and Nanoparticle (SPN foam) is used to access the trapped heavy oil. SPN is employed to stabilize CO2 foam and mobilize unrecovered heavy oil, and its performances are compared with sce-narios in the absence of nanoparticles. Surface functionalized silica Nanoparticles was used to investigate the performance on foam stability. A visual linear sand pack was used to study the foam performance during heavy oil recovery. Foams are formed in situ by co-injection of the foaming solution and CO2 gas. In static tests, the decreasing rate of foam height and foam half-life are recorded and described as foam stability. A high-quality digital camera is employed to capture images of the related phenomenon. Results reveal that the surfactant-nanoparticle-polymer foam is superior to conventional approaches in terms of foam static and dynamic stability, which indicates synergy be-tween surfactant and nanoparticles. Nanoparticles mainly involved in the liquid-gas in-terface and increase the foam stability and foamability. The addition of polymer enhances the liquid viscosity and foam stability in static tests. Moreover, foam stability is improved more obviously in the presence of crude oil. Successful foam generation and escalation were achieved in water-saturated dynamic experiment after introducing nanoparticle and polymer into the surfactant dispersion. In terms of dynamic tests in the presence of oil, foam flooding of surfactant-nanoparticle-polymer blend obtained the most desirable pres-sure drops and oil recovery. The synergism between nanoparticle and surfactant apparent-ly enhanced the foam propagations and polymer has a positive impact on foam perfor-mances. The application of nanoparticles stabilized foam for heavy oil recovery has several advantages. Besides enhancing the foam stability and foamability, the presence of nanoparticles mitigates the amount of surfactant used for foam generation.

• Subjects / Keywords

  • CO2 foam
  • Nanoparticles and polymers
  • Heavy oil recovery

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3GT5FV6V

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.