SELECTIVE DIRECT AND REVERSE CIRCULATION CHECK VALVE MECHANISM FOR COILED TUBING

摘要

A method and apparatus for selectively actuating a dual check valve assembly within a well for a direct circulating operational mode or a reverse circulating operational mode. A tubular housing which may be connected to well tubing is provided with a check valve assembly and may be provided with a rotatable J-slot mode indexing sleeve having an internal J-slot geometry. An inner tubular member which also may be connected to well tubing is linearly movable within the tubular housing to a valve open position, an indexing position and a valve enabled position being controlled by the J-slot geometry of the J-slot indexing sleeve or being controlled by moving the inner tubular element and resisting movement of the tubular housing. Relative positioning of the inner tubular member and the tubular housing to selective valve mode positions may also be achieved responsive to fluid flow, by mechanical compression, or by motion operation.