Improved Kick Management During MPD by Real-Time Pore-Pressure Estimation

Abstract

Summary Pressure maintenance within safe bounds and minimization of influx of fluids from the formation to the well during a kick are basic concerns of well control. Managed-pressure drilling (MPD) offers improved capabilities over conventional well control methods to address these concerns. In this work, we develop a methodology that capitalizes on the improved access to downhole measurements offered by wired-drillpipe telemetry to maintain pressure within desired bounds during kick management. The objective of this methodology is to improve MPD by reducing nonproductive time, reducing formation damage, and optimizing operational limits for the annular backpressure choke manifold. The proposed methodology estimates formation pore pressure automatically on the basis of real-time measurements when a gas kick is taken during MPD. The methodology relies on the characteristics of the pressure-buildup curve. Implementation of the methodology presumes the availability of standard MPD equipment for automatic annular backpressure control. A representative North Sea well is used as test-case geometry, and an advanced hydraulics model is used as a virtual well in computer simulations that provide the basis for the presented results. The proposed methodology is demonstrated to both maintain pressure within desirable bounds and reduce formation-fluid influx during a kick and thereby reduce the risk of hole-stability problems and the cost associated with nonproductive time.