Kick Management Study on Automated Well Control for Managed Pressure Drilling in Long Wells

Abstract

In drilling operations, the downhole pressure (BHP) requires to be closely monitored and precisely managed to avoid potential drilling events harmful to personnel and environment. If the BHP is lower than the pore pressure, kick (amount of influx) from formation will enter the wellbore, which might result in (underground) blowout. If not properly managed, this could be more costly than surface blowouts [1]. Well control aims to stop and remove the influx and re-establish primary barriers. Managed Pressure Drilling (MPD) is an advanced drilling technology capable of precisely controlling annular pressure profile throughout the wellbore. In this study, a high fidelity transient flow model is used for simulating dynamic well control procedure in MPD to properly manage annular pressure during kick circulation after the kick is detected. In this work, an automated well control in MPD is simulated, where PID control algorithm is implemented by manipulating choke valve opening to dynamically regulate the BHP during kick circulation. The main aim is to investigate dynamic kick management with the use of different type of muds, water based mud (WBM) and oil based mud (OBM). For different mud systems, the well control performances for long extended reach wells are evaluated and compared. From simulations, it shows that the OBM is able to hide the influx to a large extent, than the WBM due to the much higher gas solubility of the OBM. In HPHT wells, the OBM is superior to the WBM with proper automatic surface pressure control in MPD operations. Using complicated dynamic flow model can provide more precisely surface pressure control for realtime dynamic kick management.