Slim Hole Frac Strings

• 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.