While drilling at 4,470m, severe mud losses (350 bbl /hour) were encountered.
The PBL tool was activated and LCM pills were pumped with no operational issues.
The PBL was activated for a second time as the mud loss continued at a rate of 58 bbl/hour and the operator decided to pump cement slurry through the PBL. 100 bls of cement slurry with 15.8 ppg, followed by oil base mud were displaced.
The well was monitored, and as losses remained at a level of 110 bbl/hour, a second cement slurry was displaced having the same properties as before. The mud losses were finally eliminated, the PBL tool was deactivated and the flow through the directional tools was successfully restored and the remaining section was drilled without any further issues.
The PBL multiple activation bypass system demonstrated its value to the operator by preventing NPT associated with dedicated trips to perform cementing operations allowing the displacement of aggressive LCM and cement slurry multiple times. Its reliable design assures the successful protection of BHA components such as LWD and directional tools.