Automation of Drawworks and Topdrive Management To Minimize Swab/Surge and Poor-Downhole-Condition Effects

Abstract

Careless axial and rotational movement of the drillstring can cause formation fracturing or fluid influx, resulting in costly remedial actions. With increasingly complex wellbore geometries and narrow geopressure windows, it is not always obvious for the driller how to estimate accurately the real maneuvering limits of the drawworks and the topdrive, especially under poor downhole conditions. The solution presented in this paper uses continuously updated safeguards applied to the drilling-control system to maintain a downhole pressure within the acceptable limits of the openhole formations. It automatically stops the movement of the drillstring in the case of abnormal hookloads or surface torques. Because automatic actions can be triggered in the case of an unexpected situation, some standard procedures have been fully automated, including friction tests and back reaming.Numerical models are used to constantly calculate the maximum accelerations and velocities, which can be applied to the drillstring in the current drilling conditions. The resulting envelope of protection is dependent on many factors. Therefore, a proper evaluation of the downhole conditions is of paramount importance for the quality of the calculated safeguards. An automatic calibration of the physical models, on the basis of surface measurements, is at the heart of the system. The calibrated mechanical models are used to determine the limits for abnormal surface torques or hookloads. It is, therefore, possible to take actions automatically in the case of overpull, set-down weight, or high torque.In 2008, a preliminary version of the system was tested during the drilling of a well in the North Sea. Even though the control algorithms did work well at that time, it was noticed that, in some circumstances, the drilling-control system would not be ready in time for fast-changing drilling conditions. An improved version of the drawworks and topdrive automation system has been tested during the drilling of three North Sea wells in the spring of 2009. In this last version, the response time of the system has been optimal at all times. The drillers involved in the testing of the system have found the system useful and user friendly.Eric Cayeux is chief scientist of the Drilling and Well Modeling group at IRIS. He holds an MS degree in civil engineering from the Ecole Nationale des Travaux Publics de l'Etat, Lyon, France and an MS degree in software engineering from the University of Nice and the Paris School of Mines, France. For the last 20 years, Cayeux has worked on the development of software for well planning and real-time drilling-control and interpretation systems. Benoît Daireaux is a senior research scientist within the Drilling and Well Modeling group of IRIS, where he is working on drilling automation and real-time modeling of drilling operations. He holds a PhD in theoretical computer science from the University of Caen, France. Erik Wolden Dvergsnes is a senior research scientist with 8 years of experience with the Drilling and Well Modelin...

Drilling-Systems Automation: Current State, Initiatives, and Potential Impact

“…Even though surface instrumentation has lagged in development, automationquality sensors are available (Florence and Iversen 2010;Ronaes et al 2012). Software models are being developed and tested that provide monitoring and prediction capability in real time as the well is drilled (Dashevskiy et al 2003;Rommetveit et al 2004;Iversen et al 2006;Cayeux and Daireaux 2009;Cayeux et al 2011;Wong et al 2013;among others). Software models address the entire automation spectrum.…”