Managed Pressure Drilling; Overview, Modeling, and Case Study

Abstract Managed Pressure Drilling (MPD) is defined by IADC as "an adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore". It aims to facilitate safer and more efficient drilling of hydrocarbon wells by employing automated chokes to manage the wellbore pressure profile and maintain a constant bottom hole pressure (CBHP) at a specified anchor point. Since its development, MPD has gained significant popularity due to its numerous advantages. While MPD is particularly designed for drilling wells with a narrow pressure window, it helps to mitigate various drilling hazards and reduces wellbore-related problems, especially those caused by pressure deviations, such as kicks, lost circulation, stuck pipe, wellbore instability, and twist-offs. MPD is also proven to enhance drilling performance and increase rate of penetration (ROP) by reducing fluid pressure at the bottom of the well. MPD can improve well economics by reducing non-productive time (NPT) for any well. At the heart of MPD operations is hydraulic modeling, which gathers well operational parameters and calculates the pressure profile along the wellbore. Numerous rheological models are available in literature, each with their own assumptions, simplifications, and advantages. This article aims to review MPD technology, showcase a variety of successful MPD case studies, and discuss the economic and safety benefits MPD brings to the drilling industry. Then, in the main section of the paper, two MPD wells drilled with PWD tool are used to compare downhole measurements of Pressure While Drilling tools against predictions from different hydraulics rheology models. After evaluating each models' accuracy, the most reliable model is used to run a parametric analysis to assess the impact of various drilling parameters (RPM, ROP, flow rate, and mud properties) on the well's pressure profile. The case study results indicate that hydraulic modeling can serve as a reasonably accurate alternative to expensive PWD tools for predicting downhole pressure. It is also discussed that, while ROP significantly influences pressure due to increased cuttings content in the mud, RPM is another critical parameter that must not be overlooked.