Managed Pressure Drilling in Deepwater Brazil Presalt Severe-Loss Scenario

摘要

Managed pressure drilling (MPD) is a technique used to drill wells when conventional rotary techniques are inadequate. MPD technology enables narrow-window and severe-loss wells to be drilled by controlling bottomhole pressure (BHP) and through early detection of any influx or losses. This paper discusses a campaign involving three wells drilled in the Brazil presalt area using MPD technology and analyzes lessons learned. Operational procedures are primary to the analysis; however, kick detection and system logic are also discussed, as this case represents the first use of the new MPD technology in a deepwater presalt scenario. The MPD system can be divided basically into two parts: (1) the flow deviation system, which enables a closed loop to be created to control flow deviations and (2) the pressure management system, which controls BHP by opening and closing an automated choke and measuring flow out. The pressure management system is enhanced by surface equipment, such as an automated choke and Coriolis meter, and the control software that receives all the information to control choke opening and closing analyzes data to detect and control any kicks or losses. This paper focuses on the surface equipment and software applied and discusses the results, challenges, and savings resulting from MPD technology use.