METHOD AND APPARATUS FOR DISPLACING DRILLING FLUIDS WITH COMPLETION AND WORKOVER FLUIDS, AND FOR CLEANING TUBULAR MEMBERS

摘要

The mechanical separation of drilling fluid and a completion fluid byswab cups (86, 88) is used in combination with a casing scraper (90,92) andmovementof the tubing (18) to clean up a wellbore. In a first embodiment, reversecirculation isused placing a completion fluid above swab cups (86, 88) and lowering the pipe(18)to displace a drilling fluid. In a second embodiment, in combination with acasingscraper (90, 92), a completion fluid is pumped into an annulus located belowswabcups (86, 88) and the drilling fluid is displaced from above the swab cups(86, 88) byraising the tubing (18). Alternately, large swab cups (360, 362) areshearingly securedin combination with smaller swab cups (370, 372) and casing scraper (380)allowingthe apparatus to be used with progressively smaller diameter casing (310)during thesame operation of the apparatus.