Evaluation of Measurement-While-Drilling, telemetry methods and integration of control systems

Abstract

This paper will present an overview of the applications of the measurements performed by the Measurement-While-Drilling and Logging-While-Drilling tools. An evaluation of the available telemetry techniques used to transfer the measured data from the downhole tools to surface are performed, with special emphasis on Mud-Pulse Telemetry (MPT) and Wired-Pipe Telemetry (WPT). MPT is by far the method most commonly used on the Norwegian Continental Shelf. WPT is a new technology that allows a vast amount of data to be transferred, which could create new features for the MWD/LWD service, and improve on others. The paper give an overview of the current procedures applied during downhole communication with MPT, and explore the changes that could be introduced by utilizing WPT. It is shown that WPT would allow several new applications of the downhole measurements, without the same problems transferring data as MPT. WPT do not have the same proven record of high reliability as MPT. Hence, MPT is probably going to remain the preferred telemetry method in the future. The paper explores the possibility to integrate the downhole measurements into a drilling control system. It gives an example from Managed Pressure Drilling where this already has been successfully utilized, and explore different other scenarios where an integration is possible. To fully be able to exploit the downhole data, the amount of data received would need to be high. If utilized in an automation system, the driller would need to fully understand how the system works, and be given the means to override the automation system if necessary.