Analyses of Physical Data to Evaluate the Potential to Identify Class I Injection Well Fluid Migration Risk

Injection wells have been used for disposal of fluids for nearly 100 years. Design of injection well systems have advanced over the years, but environmental concerns due to the potential for migration of injected fluids remain. Fluids range from hazardous materials, to mining waste to treated wastewater. This paper presents an evaluation of wells injecting treated wastewater to assess which create the greatest risk to migration potential. Prior studies have looked at the risks of Class I injection wells for wastewater disposal, but limited data was available at that time. This research involved collecting data and evaluating the differences as a means to predict the potential for fluid migration in the wells. This study investigated variables to predict migration issues. PCA, correlation, canonical and discriminant analysis were used to identify primary variables that could lead to suspected migration. The results indicate that PCA and discriminant analysis in particular could provide useful data. Well age, depth and overlying formation were issues that might lend themselves to migration.