2018 Offshore Technology Yearbook

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36 | December 2017 | 2018 OFFSHORE TECHNOLOGY YEARBOOK | DRILLING TECHNOLOGY At 350 revolutions per minute, the tool can still measure downhole both inclimation and azimuth. "One of the quests we had [in the design] was to accurately measure the inclination and azimuth dynamically to confidently let the tool decide for itself what to do without requirements from the surface. That is a very important point of this," he emphasized. Vibration affects where energy is going in the drillstring. "For drilling performance, characteriza- tion of the vibration patterns is critical. Both tech- nologies provide triaxial measurement of shocks and vibration," Restrepo continued. The PowerDrive Xcel RSS also was shown to be effective in open-hole and closed-hole sidetracks due to the inclusion of a gyro and a customiz- able bend offset. The tool can measure rotation and stick-and-slip in magnetic interference envi- ronments. It also maintains directional control through the zone of exclusion, he added. LWD tool designed for 200 C environment Operators drilling in the Gulf of Thailand know to expect high bottomhole temperatures (BHT) and high ROPs. One Weatherford customer had drilled several wells in the area very quickly and wanted to use LWD to log the well, however the BHT was around 200 C. "It has been a real challenge for the industry to produce an LWD tool that operates at 200 C. It requires a very different approach to design, man- ufacture and then test the electronics in particular to get the tool up to that temperature rating and operate reliably in that kind of environment," said Weatherford's Clegg. "If you look at the inside of the HeatWave Extreme HP/HT LWD tool, it is very different from conventional LWD tools. During the R&D process we worked with die manufacturers and ceramic packaging vendors to combine multiple functions into hybrid modules," he explained. After completing the design part of the LWD tool, the company began testing and qualifica- tion with very rigorous and extreme tests up to 250 C. "We also did some very extreme excursions from temperatures above 200 C down to below the freezing point and back up again. This simu- lated the kind of things you'd see if you trip out of a hot reservoir onto a cold deck and then back down," he continued. The company also did the same vibration and shock testing as it would on a conventional LWD tool. "The functions of the tool are the same as they would be in a low-temperature tool. We didn't make any sacrifices in terms of functionality or data quality," he emphasized. The tool has a temperature rating of 200 C and a pressure rating of 30,000 psi. The HP/HT LWD tool includes Weatherford's vibration and monitoring technology so that the tool is able to monitor, measure and account for things like lateral vibrations at high frequency and torsional oscillation, Clegg continued. There is no time limit on how long the tool can stay downhole. "We don't have that constraint because we designed all of the component parts to operate at 200 C. We can record data at ROPs up to 720 ft/hr," he added. Operators appreciate the HP/HT LWD tool because of the accuracy of the service and the ability to maintain calibration of the tool at that kind of temperature, he said. They are also impressed by its ability to drive improvement in performance by providing reliable measure- ments," he said. n The Extreme HeatWave HP/HT LWD tool has a temperature rating of 200 C and a pressure rating of 30,000 psi. Data can be recorded at ROPs up to 720 ft/hr. (Image courtesy of Weatherford)

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