9-1/2” OD PBL® Bypass System deployed by a major Middle East operator in a challenging gas well to cure total losses


A major operating company in Pakistan activated a 9-1/2” PBL circulating sub twice in the drilling BHA to cure losses in one of their challenging gas wells.


While drilling the 17” hole section, 30-50 units of Background Gas were observed at 2,378m. The well was flow- checked and found to be static. The decision was made to pull out of the hole. While pumping and backreaming out of the hole, total losses were observed at 1,750m, with no returns at the surface.

Conclusion & Recommendation

As the first attempt to cure the losses through the bit failed, having the PBL Bypass System as part of the drilling assembly (BHA) enabled total losses to be successfully cured by using high-concentration LCM through the PBL ports without the risk of plugging the BHA/Bit.

Key facts