Model for CO2 leakage including multiple geological layers and multiple leaky wells

Area of Science:

• Geological carbon sequestration
• Environmental engineering
• Subsurface fluid flow modeling

Background:

• Geological storage of carbon dioxide (CO2) is vital for reducing greenhouse gas emissions.
• Abandoned wells pose significant leakage risks in carbon storage sites.
• Accurate assessment tools are needed for aquifer storage performance.

Purpose of the Study:

• To develop a novel framework for predicting CO2 leakage from numerous abandoned wells.
• To create a grid-free approximation for leakage rates and fluid distributions.
• To compare the framework's performance against established numerical solvers.

Main Methods:

• Utilizing analytical solutions for leakage path components.
• Developing a grid-free approximation for CO2 and brine leakage.
• Applying the model to field data from Edmonton, Alberta (500+ wells, 7 formations).

Main Results:

• The framework provides a flexible and useful method for leakage prediction.
• Demonstrated capability on a large dataset with multiple permeable formations.
• Highlighted the utility of analytical and semi-analytical solutions in this domain.

Conclusions:

• The novel framework offers reliable and quick assessments of aquifer storage performance.
• Abandoned wells can be effectively modeled as leakage paths using this approach.
• Analytical and semi-analytical solutions are valuable tools for CO2 geological storage risk assessment.