Wettability of Carbonate Surfaces in the Presence of Modified Salinity Brines
Abstract/Contents
- Abstract
- Low salinity water injection is an emerging technique to increase oil recovery in both sandstone and carbonate reservoirs. Evidence from core-flooding experiments and adhesion tests suggested strongly that wettability alteration is the primary mechanism for the incremental oil recovery in carbonates. Electric double layer expansion, mineral dissolution, and other mechanisms have been proposed to explain wettability alteration. It is unclear, however, the degree to which each mechanism contributes to wettability alteration and what conditions (i.e., salinity) should be met for each mechanism. In this thesis, a surface complexation model for both calcite/brine and oil/brine interfaces are developed and implemented in PHREEQC version 3. The model explains the influence of pH, salinity, and ionic composition of brine on surface potential of calcite/brine and oil/brine interfaces. The negative slope and magnitude of the predicted surface potential versus pH is in agreement with the zeta potential measured experimentally for calcite and oil/brine interfaces. The modeling results have illustrated that adding MgSO4 into brines shifts up oil surface potential significantly. Also, Ca2+, CO32-, Mg2+, and SO42- ions play a major role in changing the wettability of calcite. Finally, the estimation of dimensionless parameters including Peclet number and Damköhler number shows that the time scale for calcite dissolution is much smaller in comparison to the time scale for convective transport, and thus equilibration of injection water with calcite is moderately quick suggesting that calcite dissolution should not contribute to wettability alteration on the field scale.
Description
| Type of resource | text |
|---|---|
| Date created | June 2016 |
Creators/Contributors
| Author | Guo, Haoli |
|---|---|
| Primary advisor | Kovscek, Anthony R. |
| Degree granting institution | Stanford University, Department of Energy Resources Engineering |
Subjects
| Subject | School of Earth Energy & Environmental Sciences |
|---|---|
| Genre | Thesis |
Bibliographic information
Access conditions
- Use and reproduction
- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
Preferred citation
- Preferred Citation
- Guo, Haoli. (2016). Wettability of Carbonate Surfaces in the Presence of Modified Salinity Brines. Stanford Digital Repository. Available at: https://purl.stanford.edu/sk199by8463
Collection
Master's Theses, Doerr School of Sustainability
View other items in this collection in SearchWorksContact information
- Contact
- brannerlibrary@stanford.edu
Also listed in
Loading usage metrics...