(under subclass 285) A process comprising forcing the cement down a tubing or casing in the well and separating the traveling body of cement from an adjacent fluid by a piston means at an end of the cement body.
(1) Note. The piston means may itself comprise a fluid of limited longitudinal extent which functions like a solid piston.
SEE OR SEARCH THIS CLASS, SUBCLASS:
153+, for well devices comprising pistons fluid driven into the well.
