Applications
The operator was drilling ahead in the 8 1/2" section and encountered total losses at 7469 ft, with 10.9 ppg SOBM. Attempts were made to stop the losses, but they were unfortunately unsuccessful. The client switched to PMCD drilling, they drilled ahead with light 9.3 ppg WBM, after reaching TD 8822 ft MD, they stripped out the open hole section until the biut was back inside the 9 5/8" casing shoe. LCM was then used again to cure losses but unfortunately it was unsuccessful.
Solution and Achievement
After a discussion with Coretrax, the client decided to run and set a 9 5/8" Coretrax CX-2 cement bridge plug alongside Drillable Brush (CX-DB). The CX-2 was RIH on drillpipe and set hydromechanically 150 ft inside the 9 5/8" shoe. The CX-2 setting depth was 7010 ft. After successfully setting and pressure testing the CX-2, 50 bbls of cement was then pumped immediately after, on top of the CX-2 and the work string POOH.
A whipstock was RIH and set in the 9 5/8" casing to side-track and drill an alternative 8 1/2" hole. This was done successfully with no losses encountered, a 7" liner was run and cemented and the 6" section was then drilled out without incident.
Initially the client did not intend to run the CX-2 and drillable brush during total loss scenario, however, the use of both these tools in combination provided a single trip solution for what could have been a potential 3 trip situation.
The CX-2 performed flawlessly, allowing the well to become static and allow the remedial side-track operation to commence.
Time taken from RIH with the CX-2 and CX-DB to POOH to surface, 2.625 hours.
Key Benefits
The CX-2 and drillable brushes design allows the casing section to be mechanically cleaned, the CX-2 plug set and the cement pumped all on the same trip into the hole.
CX-2 incorporates a slick stinger with a through-bore that eliminates a need for a dedicated trip for cementing operations and reduces cement disturbances when pulling out of the cement plug.
The CX-2 and CX-DB was run in tandem to successfully set and be pressure tested. This allowed the well to become static, saving time and securing the well from what potentially could have been a well control situation.
The client was able to run the tools themselves with 24hr support and instruction from Coretrax.
The client was extremely pleased with the outcome. They were able to resolve the total loss scenario that could have cost multiple days of NPT.
