Inflatable packers are ideal for through-tubing zonal isolation, but they are rarely used in extreme environments because of the assumed risk of failure. High pressures, high temperatures, high expansion ratios, and chemical resilience are particular challenges. This paper reports on three recent case histories that demonstrate inflatable packer technology can be used in several of these “harsh” wellbore conditions. The first case history describes a high-pressure cement squeeze job using a 2 1/8-in. packer with an expansion ratio larger than 3:1. The objective was to run the packer through a 2.313-in. restriction and set in 7 5/8-in. casing to permanently shut off a lower water zone before perforating higher in the well. The second study involves an inflatable packer used in conjunction with a butyl acetate furan resin for sand consolidation. The furan resin is known to be extremely detrimental to elastomers, so a full-scale simulation under given wellbore conditions was conducted to demonstrate its compatibility with the packer. The resin was utilized as a screenless sand-control solution that allowed fullbore production. The final case history involves pumping of a viscoelastic acid-diverting treatment fluid, used for matrix stimulation under high-pressure, high-temperature conditions. Used in carbonate formations, the fluid is ideally suited for total zonal coverage matrix simulation and high temperatures. When a through-tubing inflatable packer is used as a treating packer, individual long producing zones can be fully isolated and evenly stimulated.
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