Application of Managed Pressure Drilling on a Semisubmersible Tender-Assisted Rig to Address Drilling Challenges in HPHT Gas Condensate Wells, Offshore Vietnam

Abstract High-pressure, high-temperature (HP/HT) environments often present kick and losses scenarios. Bien Dong POC Well-1 serves as an example of such scenarios with a very narrow-pressure operating window. Operational pressure challenges prohibited achieving the objectives. While drilling the Bien Dong Well-1, the well encountered ballooning issues, high pore pressures, and a narrow window. As part of remedial actions when drilling Bien Dong Well-2 & Well-3, the Bien Dong POC drilling team decided to deploy MPD technology with constant bottomhole pressure and early kick-loss detection capabilities. By applying MPD techniques, the team drilled the 12-1/4-in. hole section with the lowest possible mud weight to accommodate the narrow drilling window. Drilling the well sections to total depth (TD) took only 10 days in Well-2 and 14 days in Well-3. MPD also allowed stripping out of the hole with surface backpressure (SBP) instead of pumping out of the hole to minimize swab once in shoe, which reduced trips for considerable rig-time savings. The wells were drilled using MPD technology on a semisubmersible tender-assisted rig. A comprehensive rig survey was conducted during the planning phase of rig construction. The survey outlined the permanent installation of the MPD system, including an automated MPD choke manifold and docking-station rotating control device (RCD). The MPD equipment was integrated into the rig on a flexible plug-and-play basis to enable easy rig up and rig down. The integration also enabled moving the equipment between wells when the rig skids and during the MPD operation. The success of MPD operations came through cooperation with team members, experience from lessons learned, and excellence in rig crew performance on well after well. This paper will discuss how MPD technology led to campaign improvements and cost savings throughout Bien Dong Well-2 and Well-3.