Abstract

The objective of the paper is to present a case where a Managed Pressure Drilling (MPD) and an MPD Well Design process was used to design and drill a deepwater exploration well with an expected pressure ramp and narrow drilling margins while acquiring valuable subsurface data. The expected pressure ramp and narrow drilling margins combined with the uncertainty of subsurface data presented significant challenges to the well design team. Based on previous experience in the region, reaching well TD safely and efficiently using conventional drilling methods was predicted to be challenging. The MPD Well Design process enabled MPD techniques, including constant bottom hole pressure and dynamic influx management, to be integrated into well design process. MPD was also identified as a critical tool to collect dynamic pressure data and help reduce overpressure uncertainty. The drilling program, rig specific operations, and contingency procedures were developed accordingly. MPD was used to successfully drill through a pore pressure ramp and address a well control event in conjunction with conventional methods. MPD was also an enabler to optimize the location of the casing/liner shoes by identifying the pressure profile based on real-time pore pressure data. This feature was a key advantage to drilling deeper than planned and resulted in effectively saving one casing string. The proposed well design included five casing/liners, with potential for two contingencies. With the implementation of MPD, the actual well was drilled with four casings/liners to a deeper TD and met all evaluation objectives under budget. This paper presents a case for using MPD and the MPD Well Design process and its full capabilities to optimize all aspects of a well delivery process, including well design, safety, and subsurface data acquisition.

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