DURATION
It took three months of engineering and pre-job planning for an 8-month project.
THE SITUATION
A major oil company decided to switch to propane fracturing on multi-zone wells. After third party engineering of wellbore design, 4-1/2" casing was under loads of up to 95% of its tensile strength during fracs. Decisions were made to run 2-3/8" frac strings to isolate the top 550 m of casing, snub out the string and run composite plugs. They then re-ran the frac string and continued this procedure six times per well. All previously drilled wells would be completed in this fashion, and all new wells would be cased in a heavier premium pipe.
THE SOLUTION
We developed a plan to snub the following BHA:
- Re-Entry Guide
- XN Profile
- 10' Pup Joint
- Eskimo Packer
- XN Profile
- 10' Pup Joint
- 55 Joints of Tubing
- Nickel Coated 10' Pup Joint
- 7-1/16" Tubing Hanger
The pipe was run at pressures between 4,000 – 7,000 psi of liquid propane. After initial operations, the pipe was washing, so a new pipe was used for fracs. After all the zones were completed, the snubbing units were used to mill out the composite plugs and land production strings.
