Achievement for EM tools
APS Technology's SureShot™ EM MWD System has successfully transmitted from a depth of 10 104 ft (3080 m) total vertical depth (TVD) in a Canadian well in oil-based mud (OBM). This is the deepest transmission to date for the APS EM system, marking an impressive achievement for EM tools in general.
"We were very pleased with the tool's performance," said Andy Roberts, APS's EM Project Manager. "The signal was strong. We expected a lower frequency and data rate would be necessary at this depth, but we were able to transmit at 6 bits per second and 6 Hz despite the depth and oil-based mud, which is more difficult for electromagnetic telemetry."
"Our patent-pending, quad-channel receiver proved invaluable on this well," Roberts said. "The field engineers were able to compare signals from different antenna pairs seamlessly and quickly zero in on which were receiving the best as conditions changed. I doubt they would have made it to this depth without it."
Communicating with the downhole system was accomplished with EM downlink telemetry using a transmitter at the surface. EM downlinking is faster than a cycling pump or rotation and is achieved without interruption to drilling operations. Downlinking was typically used to tell the tool to uplink on a different frequency when noise appeared on the current frequency.
APS's SureShot EM MWD operates at up to 12 bits per second and 12 Hz. Maximum transmit power is 50 watts. It is available in 4.75 in. (121 mm), 6.50 in. (165 mm), 6.75 in. (172 mm) and 8.00 in. (204 mm) sizes.
Adapted from a press release by Louise Mulhall