Managed pressure drilling is a technique viewed as a means of improving the chances to drill the most challenging wells. Wellbore pressure management allows operators to address key technical risks such as narrow pore pressure and fracture gradient windows, sensitive wellbore stability environments and navigating steep and unknown pore pressure ramps. Certainly, the technology delivers added advantages while the drilling team attempts difficult wells. Successful execution, however, requires awareness of all aspects throughout the drilling process and full integration of the entire well construction team. Even best laid plans can encounter challenges that quickly become insurmountable. Despite being on alert, as is most often the case with MPD wells, misunderstanding subtle signs throughout the drilling process, poorly synchronized execution or untimely technical failures can lead to catastrophic outcomes for the operator. Additionally, it is not until execution when a full understanding of the wellbore sensitivity to pressure swings becomes apparent. The authors will look at a series of uniquely different wells, all employing MPD but for different technical reasons. Exploration drilling through challenging pore pressure ramps, high angle and horizontal wells across formations highly sensitive to pressure cycling, PMCD wells and wells drilled through very narrow pore pressure and stability window across depleted zones. Analysis of the detailed design during the planning phase, with the information that was known at that time, will lay the foundation of how each well was executed. In each case, the desired outcome was not achieved for reasons unique to the respective project falling outside the core MPD engineering design. Analysis of the failures will identify key lessons learned and show progressive continuous improvement that has made MPD critical to success on future projects and raised confidence of the users.

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Repred for U. S. Atomic Energy Ccjrnmission under contract no. W-7405-Eng-48 ~RsTER N O T I C E the United States nor the United States Atomic Energy Cornmimion, nrrr m y of their employeen, nor any of their contractors, subcontmctors, or their employees, nukes any warranty, express or Implied, or assumes any lagrl liability or responsibility for the accuracy, completeness or ussfulner of any information, apparatus, product or process disclosed, or represents that its use would not infringe pfivntoly owned rights.

Objectives/Scope Industry deepwater exploration and development continues to encounter complex reservoir challenges, demanding an alternative to conventional drilling. Applied backpressure Managed Pressure Drilling has proven to be a solution suitable for similar challenges on land and shallow water. Some projects around the world have expanded the application to deepwater. The degree of complexity for such a solution in deepwater is such that it remains niche. To deliver a successful solution, operators have relied on integrating components from multiple providers to ensure a complete system. The package is customized for each drilling rig, further adding complexity to the integration exercise. Because each component of the system is delivered from separate suppliers, the certification of the system by an appropriate agency must then be approved on a case-by-case basis to guarantee insurability of the offshore drilling unit. Beyond certification, the ability to optimize the package was limited by barriers inherent in a multi-supplier solution. Methods, Procedures, Process In 2016, a drilling contractor requested an integrated deepwater MPD package, aimed at adding versatility to their rig fleet. A fully integrated, single Original Equipment Manufacturer solution was designed and manufactured to meet the objective of MPD enablement for a package designed to move throughout the fleet. The design, manufacture, install and system integrity test of all components for two drilling rigs took place over a 12-month period. The system was witnessed and certified by DNV GL. First field deployment took place in late 2017. Results, Observations, Conclusions This paper describes the complexities of delivering a fully integrated deepwater MPD package, including RCD, riser gas handling system, MPD control system and pressure and flow management hardware as a first artifact with DNV GL OS-E101 classification. Novel/Additive Information The solution described is an industry first complete OEM deepwater MPD system.