Disconnect check valve mechanism for coiled tubing

摘要

A tubing conveyed disconnect check valve mechanism having releasable connection with a payload tool and being selectively actuated downhole for disconnecting from the payload tool for retrieval by the tubing string, with the check valve enabled for direct circulating flow and preventing the inflow of wellbore fluids, while permitting the payload tool to remain in the well. A housing is connected to a tubing string, such as coiled tubing, and incorporates at least one check valve and defines a first disconnect connector which is releasably connected with a second disconnect connector of the payload tool housing. A check valve positioning mandrel is releasably retained at a check valve disabling position within the housing for establishing a reverse circulating flow path through the check valve and is released from the housing and moved to a check valve enabling position, closing the reverse circulating flow path and permitting direct circulating flow only.