High pressure isolation system for well stimulation through production tubing

摘要

A fracturing system 22 includes a fracturing spool 24 that mounts onto a wellhead assembly 10 for injecting fracturing fluid into a well beneath the wellhead assembly 10. The fracturing system 22 includes an isolation sleeve 52 and fracturing spool 24. The isolation sleeve 52 inserts in an axial bore 53 of the fracturing spool 24, and has a lower end that extends into the wellhead to isolate and protect portions of the wellhead assembly 10 from the fracturing fluid. A groove in an inner surface of the fracturing spool 24 receives an annular seal for sealing between the isolation sleeve 52 and fracturing spool 24. Injecting a viscous fluid into the groove energizes the seal, and blocks high pressure fracturing fluid from flowing between the isolation sleeve 52 and fracturing spool 24.