AkerBP select the 7″ AVS for their Valhall F11 well. This was a sidetracked well that has tremendous stick / slip. The AVS was run in the 8 1/2″ BHA for drilling out the 9 5/8″ liner shoetrack and drilling ahead. The AVS was run successfully in Splitflow mode but suffered a problem when trying to go into Bypass for POH. Later investigation showed the MEMS gyro PCB had suffered a micro fracture meaning the gyro, which reads RPM was making spurious readings. The micro fracture was due to an induced stress i.e slight bending when the AVS was being assembled in IDT’s assembly room. Procedures have been changed to ensure this does not happen again and the introduction of the V2 software, which allows downlink via multiple methods including pump cycles, pump duration and differential pressure, means a downlink can be made even if the Gyro fails.
