Improving Well Integrity Assessment Through the Feature, Event and Process (FEP) Methodology Applied to Each Wellbore Barrier

Abstract Well Integrity assessment becomes difficult for old wells when vital information is missing. A risk assessment approach, however, could highlight the component to be investigated first, thus saving the company time and money. Risk assessment methodologies have been successfully used for CCUS and Geothermal wells; therefore, a modified Feature Event Processes concept has been designed and implemented. The unique feature of the modified Feature, Event, and Process (FEP) is that we apply the concept for each wellbore barrier, and then we finally create an overview of the selected well. This concept can also be used for new well designs, allowing for a comparative review of the well integrity measures considered for each design. For old wells, the proposed method will identify the most vulnerable wellbore barrier and point to the part of the well that needs immediate attention. As mentioned above, we can generate a well integrity score for the whole wells based on the well integrity potential, simplifying the wellbore geometry selection. The paper will first provide a brief introduction to the FEP methodology and the proposed modifications to allow for multiple wellbore barrier applications. We will then use selected synthetic wellbore configurations to document the method’s applicability and lessons learned. Our results clearly show that although it is a quantitative methodology, the modified FEP method can be automated and applied to any well configuration. We also found out that increasing the number of wellbore barriers may not always increase the well integrity of a given well.