Lessons from Risk Assessment of 6th Generation Drill-ships and Semi- Submersibles

Abstract

Building a deep-water drilling rig that incorporates the latest technology while meeting internal requirements, client specifications, and budget constraints, can be a daunting challenge. Doing so in a post-Macondo environment with a shortage of qualified personnel to man the rig adds even more obstacles to overcome. Ensuring that a variety of rig systems supplied by different vendors will be integrated into a workable rig that is properly maintained is another task for the drilling contractor. The risk management plan was implemented in the form of individual risk assessments focused on each of various systems utilizing primarily the failure modes effects and criticality (FMECA) methodology. It can be quite surprising to evaluate the results of these sessions and realize how powerful these tools can be and how effective they can be in identifying potential faults and weaknesses in the systems. Maintaining a global view of the rig while carrying out the individual risk assessments was critical to ensure overall integration of the systems. The paper results will highlight examples of findings across a wide spectrum of rig systems, from the cooling water system of active heave drawworks braking resistors to NOVEC release on an F&G detection system to challenges on a pipe handling system. Each example will have its own unique circumstances, but they all highlight the importance and value of implementing an effective risk management strategy. This paper also demonstrates that implementing a risk management plan during the design and construction of the rigs can help reduce risks associated with major accidents and downtime. This can be accomplished by applying the results of the risk assessments into training of personnel, updating of operational procedures, updating of maintenance procedures, modifying designs, changing control systems and re-programming software. This paper presents the results of risk assessments applied to semi-submersibles and drill-ships, all 6th generation deep-water drilling rigs.