Treating high pressure zones in one trip in Canyon Reef area of Texas

In the Canyon Reef area near Snyder, Texas, Chevron U.S.A. Inc. is employing ratchet operated, packer type retrievable bridge plugs which have allowed operators to test, treat, or squeeze high pressure zones over a 35-day period on a single trip of the workstring. More zones could have been treated if necessary. The bridge plug was moved and set 31 times while treating the zones. Elapsed time is shown in days starting with T-date being the day tools were first run in for the treatment. The job was run with an average treating pressure of 1,000 psi, and a differential pressure of 2,500 psi that alternated from above the bridge plug to below and back each time the plug was moved to a new zone. The bridge plug used for the job seals by the action of a patented ratcheting mechanism which requires relatively light weight to set. Design of the ratchet enables the sealing elements to hold a seal against the casing wall while the hold-down slips are being set.