_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 216484, “Optimization of Well-Diagnostics Investigation,” by A. Yugay, SPE, A. Zhukin, and S. Vorozhikhin, ADNOC, et al. The paper has not been peer reviewed. _ The complete paper defines the conditions for optimized well-diagnostics investigation, allowing preservation of resources and minimization of response time to well failure. It also describes a rigless solutions for common well-barrier failures and lessons learned from the operator’s field trials. This information is valuable for companies aiming to optimize their sustained annulus pressure (SAP) well-management process. The main objective of the paper is to identify scenarios in which the failed barrier element can be recognized from surface data alone. SAP Management Well-diagnostic activities can be divided into two classifications: surface activities and subsurface activities (well interventions). Common surface investigation activities include the following: - Bleedoff/buildup test - Sampling and analysis of the effluent - Wellhead seal test - Revision of well history - Leak-rate measurements - Echometer surveys - Pressure tests - Tracers Subsurface well diagnostics may include the following: - Pressure and temperature surveys - Corrosion logs - Leak-detection logs - Mechanical communication tests - Fiber-optic surveys - Various slickline tools - Installation of downhole gauges Root Cause Analysis (RCA) of Premature Well-Barrier Failures For wells with premature integrity failures (when the failure occurs within 10 years of the last rig entry), a new RCA process was implemented. Enhanced SAP investigation is conducted to identify exactly which well-barrier element failed. In the majority of cases, it is reverified during workover, after the completion is pulled to surface, and is available for visual and other types of inspection. The process includes third-party inspection and material testing, manufacture inspection, independent consultancy services, software simulations, and analytical brainstorming. On the basis of the confirmed direct causes, a multidisciplinary team conducts a full investigation of the failure, attempting to identify root causes. With the root causes identified, the team develops an action plan with fixed deadlines and specific actors. All findings and observations, along with the analysis and final outcome, are captured in the reports, presented to the management, and cascaded for implementation and improvement. The multidisciplinary team is staffed by representatives from drilling, production, and engineering departments. Thus, this group is no longer considered a “task force”; instead, a completely new dedicated business process has been implemented, created with a budget and resources allocated to move forward with continuous improvement.