METHODS OF DISPLACING LIQUIDS THROUGH PIPES

摘要

Improved methods of displacing a first liquid through a pipe with a second liquid while preventing the first and second liquids from mixing are provided. In accordance with the methods, a plug is formed in-situ in the pipe between the first and second liquids by injecting a self-thickening liquid therein and permitting the liquid to thicken. The formed plug and the first liquid are then displaced through the pipe with the second liquid. The methods are particularly suitable for carrying out subterranean well bore cementing operations wherein cement slurries are displaced through pipes disposed in well bores.