REVERSE CIRCULATION CEMENTING PROCESS

摘要

A method of cementing a casing in a wellbore with a tool having a plurality of holes (21) therethrough connected at a lower end of the casing. A plurality of stoppers (30) are pumped in a leading edge of a cement slurry (13) down an annulus (14) between the casing and the wellbore to the tool where the stoppers engage the holes to hold the cement slurry in the annulus until the cement slurry hardens. A valve maybe incorporated with the stopper catch tool (20). Stoppers and holes may have various shapes and centrifugal pump (60) may be used.