Root Cause Analysis of a Deepwater Wireline Logging Operation Train Wreck

Abstract

Abstract Detailed case studies of unsuccessful wireline operations remain scarce in the public domain, particularly in deepwater environments. This paper examines the safety, operational, and financial consequences that can arise when robust planning processes, operational controls, and experienced personnel are not fully integrated into the design and execution of complex deepwater wireline openhole logging operations. It analyzes a sequence of incidents during a wireline formation-testing and fluid-sampling operation that progressively deteriorated into a major operational failure. The root causes and contributing factors are examined to identify opportunities to improve planning, execution, decision-making, and risk management. The deepwater well, drilling-fluid systems, logging objectives, wireline equipment, and operational constraints presented in this paper are based on several real events. The operational scenarios and failure mechanisms examined are based on the author's two decades of global experience in wireline deployment and operational assurance. Wireline force-modeling software was used to evaluate deviations from the original operating envelope, and to reconstruct critical stages of the operation for root cause analysis. The paper guides the reader through the effects of drilling-plan deviations on the wireline fluid sampling operation execution, the emergence of operational problems, and the subsequent decision-making process. Particular attention is given to the implementation of a Strip-Over fishing operation and the sequence of technical and operational decisions that ended in a catastrophic outcome. The resulting root cause analyses identify technical, procedural, organizational, and human-performance contributors and assess the associated operational and financial consequences. Key lessons learned and practical mitigation measures are presented to help operators and service companies prevent similar events or limit their consequences in future deepwater wireline operations. This paper provides an experience-based reconstruction of how an initially manageable operational problem can escalate when changes in the well conditions, contingency planning and execution controls are not effectively managed.