Today's drilling optimization process depends greatly upon post-well analysis of recorded downhole drilling dynamics. Sophisticated downhole sensors are limited by wireless telemetry systems that offer a relatively limited bandwidth with considerable latency. Real-time knowledge of subsurface conditions could improve drilling processes and allow the automated, closed-loop control of surface parameters based on high-frequency downhole data.
This paper describes the development and field deployment of a new, high-frequency downhole measurement tool. This tool transmits multi-sensor data in real time through a wired drillstring telemetry system, virtually eliminating latency. This enhanced dynamics tool, which acquires downhole measurements at 800Hz, includes tri-axial vibration, RPM, downhole weight on bit, and downhole torque, as well as annular pressure and temperature.
This data is instantaneously streamed to the surface and available at 80Hz for processing by surface acquisition systems. An advanced auto-driller controls the applied surface weight on bit based on the downhole dynamic measurements. Essentially, high-frequency downhole parameters become independent setpoints, supplementing information to the once-independent surface setpoints.
This paper provides details regarding a two-month field test of 6¾" dynamics tools in six wells to quantify the operational impact of the new technologies and operating processes covering vertical and directional 12½", 8¾" and 8½" hole sections. Comparison is offered for drilling both with air and with fluids, as well as drilling with positive displacement motors and with rotary steerable systems.
The field test included establishing a benchmark in the first well, followed by utilizing multi-axis vibration measurements over the course of the subsequent five wells to actively mitigate the shocks and vibrations. Operational performance was further optimized in the subsequent runs incorporating automated control of downhole weight.