Slim Hole Frac Strings

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Slim Hole Frac Strings


    It took three months of engineering and pre-job planning for an 8-month project.


    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.


    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.