Deep water projects are presently complex, where more drilling challenges can be encountered and higher uncertainty increases the risk of problems during the well construction phase, especially due to the narrow pressure window environments. Managed Pressure Drilling (MPD) is one of the technologies that is currently gaining acceptance since demonstrating that it helps control these problems, minimizes the risks, and optimizes the overall well construction process in deep water applications.
MPD is being used not only during the drilling phase, including techniques such as Constant Bottom Hole Pressure (CBHP) and Pressurized Mud Cap Drilling (PMCD), but also is being implemented because of the benefits of identifying and controlling formation influxes while drilling and/or during connections, controlling wellbore pressures during connections, and while tripping in and out of the hole. Continuous circulation systems (CCS) are also widely used in exploratory wells to enhance control of the wellbore pressure during connections and are being used either in conjunction or without MPD. Once the well has been drilled and the completion has been run in hole, the next step is cementing the casing or liner in place. Managed Pressure Cementing (MPC) can also be implemented and brings additional benefits during this phase such as more precise control of the pressures, allowing the use of lighter fluids, and better monitoring of the overall process.
Different case histories from several areas will be described in this paper to illustrate the drivers, implementation, and results of the various MPD techniques that can be used during the well construction phase including CBHP, PMCD, CCS, and MPC. The paper will also highlight the synergies among these different technologies and how they would further benefit deep water operations.