Wired drill pipe (WDP) telemetry has been used in over 100 wells worldwide to create a drillstring network that provides high bandwidth communications between tools deployed in the wellbore and the surface. When applied to managed pressure drilling (MPD) and underbalanced operations (UBO), wired drill pipe offers substantial benefits. Because of its independence from fluid flow, it gives visibility to downhole conditions where never before possible, including environments where traditional telemetry methods are not supported, and time intervals where pumps are not operating. Similarly, memory-quality data can be provided real-time from measurement tools located in the bottom hole assembly (BHA) as well as at points along the drillstring. Specific case studies and lessons learned from using wired drill pipe in the underbalanced and managed pressure drilling environments are summarized, as are recent enhancements to the wired drill pipe system, and their impact on extending the operating envelope and reliability of wired drill pipe.
Methods for leveraging the increased quantity and quality of real-time data to improve the drilling process are important if the highest value is to be obtained from high-speed telemetry technology. To this end a novel automated borehole pressure (BHP) control system with predictive technology has been designed. A preliminary UBO case study is used to assess the performance of this controller during different drilling events, including a drill pipe connection procedure and an unexpected gas influx. While making a connection, the controller maintains tight pressure control and may enable efficiency improvements by allowing faster trip speeds, when offered as part of an automation system. For the gas influx case, the ability of the controller to properly control the influx is shown to be dependent on low latency communications, such as that provided by WDP. This controller offers a substantial decrease in time required to control influx events as compared to manual methods and earlier controllers.
A nonlinear model predictive controller and a nonlinear estimator are used in the automation study. Information available from multiple sensors arrayed in a WDP system was found to be very useful in model parameter estimation, including friction factor and annular fluid density.
Proper application of WDP technology to challenges experienced in the UBO/MPD environment can yield more cost effective and successful deployment of these methods, further improving the value UBO/MPD technology can provide. Future work will included continued development of the control system to more fully capture the value of wired pipe technology.