A Review of Well Integrity Based on Field Experience at Carbon Utilization and Storage Sites

Abstract

Maintaining well integrity is critical to the success of geologic carbon storage (GCS) and carbon dioxide enhanced oil recovery (CO2-EOR) operations. Wells that experience leakage because of integrity issues can potentially become a risk to the environment or human health if they release previously captured CO2 back into the atmosphere or into freshwater aquifers. There are many GCS and CO2-EOR sites in operation around the world. However, well integrity experiences at these sites are not widely documented in the public domain. This study details findings from a survey of well integrity experiences elicited from operators of GCS and CO2-EOR sites. The goal of the survey was to obtain information about site characteristics and operator experiences with well integrity, monitoring methods, and risk assessment of legacy wells. Literature relevant to the survey questions was also reviewed and summarized to provide context for survey responses and identify areas where field experiences with well integrity do and do not align with the current state of research. We highlight the current state-of-practice, identify research needs, and provide context for future interactions between researchers, operators, and regulators on issues related to well integrity.