Risk Analysis for Wells in an Active CO2-Enhanced Oil Recovery Field in Farnsworth Unit, Anadarko Basin, Texas

The Farnsworth Unit in the Anadarko Basin, Texas is the location of an ongoing CO2 storage and enhanced oil recovery project. Reservoir pressure increases may pose detrimental effects on wellbore integrity in the area. In this study, we investigate well historical data of 20 wells in Farnsworth Unit and conduct laboratory experiments to study risk analysis for those wells. In the experiments, the authors use Portland cement class C and H. This study also uses permeability measurement and X-ray computed tomography to quantify cement damages, then develop hypothetical correlations between injection-confining differential pressure and cement permeability. Finally, the authors apply the correlations for wells in the field to estimate leakage rates through cement columns due to wellbore damage caused by cyclic loading. This paper demonstrates the success of using permeability measurement and X-ray computed tomography to investigate damages in cement, as well as the feasibility of using both experimental and historical data to study well integrity through risk analysis. The study also mentions the corrosive effect of chloride ion on steel, which is also a factor to consider when design wellbore cement.