Combining multiple tools or processes can provide creative answers to old problems. An Algerian well was producing from two perforated intervals. The upper zone was previously fractured; the lower zone was underperforming. Stimulation treatment using a hydrofluoric-based acid system was designed for the lower zone to significantly increase the well production. Although there was confidence in the stimulation design, certain operational challenges needed to be addressed. To maximize the economics, the workover operation had to be rigless. The decision was made to use coiled tubing with a newly designed through-tubing inflatable packer to mechanically isolate the zone and deliver the harsh fluids required for the stimulation. The next challenge was setting the packer in a 3-m window between the two zones. If the packer were not correctly positioned the treatment, undeniably, would be misplaced. A wireless casing collar locator (CCL) with pump-through capability was chosen to provide accurate, real-time depth readings prior to setting the inflatable packer in a modular combined tool string.

The designed workover required only a single trip in the well, and the production tubing did not have to be retrieved. With the creation of a real-time correlation log, the inflatable packer was set on depth, and the hydrofluoric-based acid system was pumped into the underperforming zone. Post treatment, the oil production more than tripled. Two technologies were combined in an innovative application that met all operation objectives.

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