Drilling wells in high-pressure, high-temperature (HPHT) reservoirs is often characterized by a narrow operating window between formation pore pressure and fracture pressure. Depletion further reduces this window. Managed Pressure Drilling (MPD) provides methods for operating within safe limits in the narrow HPHT windows. Exceptional control over downhole pressures can be achieved with advanced MPD technologies that are uniquely suited for the HPHT environment. Such control can extend achievable HPHT targets, yet still have the flexibility to deal with the troubles that so often arise in these difficult environments.
The advanced MPD system developed for StatoilHydro's Kvitebjørn HPHT field are presented along with experiences from their use in the field. This includes:
Running a real-time, online, advanced dynamic flow model
Automatic dual redundant choke system with continuously updated pressure set-point from the flow model
Continuous Circulation System (CCS)
Pressure Control While Drilling (PCWD)
Caesium Formate mud system - A designer mud containing formation strengthening particles.
Balanced Mud Pill (BMP) - An innovative fluid technology developed for performing a precision top kill, producing minimal pressure surge when pulling the drillstring and running liner.