Comparison of various reactive transport simulators for geological carbon sequestration

Embargo End Date
2022-08-05

Type
Article

Authors
Addassi, Mouadh
Omar, Abdirizak
Ghorayeb, Kassem
Hoteit, Hussein

KAUST Department
Ali I. Al-Naimi Petroleum Engineering Research Center (ANPERC)
Energy Resources and Petroleum Engineering Program
Physical Science and Engineering (PSE) Division

Online Publication Date
2021-08-05

Print Publication Date
2021-09

Date
2021-08-05

Submitted Date
2021-05-10

Abstract
The capabilities of reactive transport modeling codes for geological carbon sequestration have improved significantly in the past decade. Comparing different geochemical modeling codes is crucial to identify modeling discrepancies, especially when experimental validation is not feasible. However, it is challenging to consistently get comparable results, as shown in previous studies where batch reaction of CO2 storage using different simulators sometimes resulted in significant discrepancies in their outputs. In this study, we introduce and demonstrate an approach to consistently produce comparable batch-reaction modeling of kinetically controlled CO2-water-rock interactions in PHREEQC, TOUGHREACT, and GEM, which are amongst the most widely used simulators for CO2 sequestration studies. The primary step is to assemble a thermodynamic database in PHREEQC format, with representative fluid properties for CO2-water interaction, and carefully convert it to the format of the other simulators. We use two case studies from the literature to demonstrate our method where good matches between the outputs of all three simulators were achieved, which was not previously attained. Furthermore, limiting the discrepancies in batch-reaction models provides a consistent baseline to study the coupled mechanisms of transport and chemical reaction, which was also successfully demonstrated with a one-dimensional reactive transport model in PHREEQC, GEM and TOUGHREACT.

Citation
Addassi, M., Omar, A., Ghorayeb, K., & Hoteit, H. (2021). Comparison of various reactive transport simulators for geological carbon sequestration. International Journal of Greenhouse Gas Control, 110, 103419. doi:10.1016/j.ijggc.2021.103419

Acknowledgements
The authors thank King Abdullah University of Science and Technology (KAUST) for supporting this work. Thanks to USGS, LBNL and CMG for providing the simulators PHREEQC, TOUGHREACT and GEM respectively. Thanks to David Parkhurst and Eric Sonnenthal for their support with PHREEQC and TOUGHREACT respectively.

Publisher
Elsevier BV

Journal
International Journal of Greenhouse Gas Control

DOI
10.1016/j.ijggc.2021.103419

Additional Links
https://linkinghub.elsevier.com/retrieve/pii/S1750583621001717

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