An Introduction

Have you ever wondered whether the techniques we use for assessing hydrocarbons can be applied to subsurface carbon storage (SCS)?  The methods we use to quantify the range of hydrocarbon volumes and chance of success (risk) have been established and refined over more than five decades. It is indeed possible to extend these to CO₂ storage, but not without some modifications.

The objective of SCS projects is the permanent storage of CO₂. This requires a framework to assess both uncertainties and risks over hundreds to thousands of years. The assessments must cover site identification and appraisal of the storage complex, injection of CO₂, pressure monitoring, and post-injection monitoring to ensure long-term retainment. This very long-term risk assessment requires additional skills and methodologies that are not generally required for oil and gas projects.

Moreover, we’d argue that a paradigm shift is required so we focus on the chance of geological failure, rather than the chance of geologic success. A failed petroleum exploration well can simply be plugged and abandoned. Not so with a CO₂ injector if it was shut-in due to the CO₂ ending up in the wrong place. This could impact adjacent subsurface operations, contaminate shallow aquifers, and pose significant legal liabilities. Such unplanned events can taint the entire emerging SCS industry.  We’ll discuss this in our next post.