Cemented Liner Hanger for flush-joint pipes PHCBT is applied for RIH and continuous
cementing of a liner consisting of flush-joint pipes.
The PHCBT liner hanger consists of the top sub and the body joined with the bottom sub by
special left-hand thread. There is a special groove in the body that holds the collet supported
by the piston which is held by shear bolts. There is a suspended plug positioned within the
inner channel of the device mounted with two hollow shear plugs.
The device operates as follows. While liner cementing top wiper plug is touching down the
suspended plug seat and the shearing of two hollow plugs is performed due to the pressure build-up, the access of fluid to the plunger space is opened. The pressure build-up
is performed after receiving the “stop” signal, shear bolts are ruined and plunger moves
releasing a collet. Under tension the blades of the collet clench and therefore the liner is
disconnected from the transport string.
The liner hanger is equipped with the mechanical breaking unit doubling the hydraulic one.
It is actuated by transport string rotation to the right.
The device application area is vertical, tilting (flat) wellbores and bores with horizontal ends
whereinto casing strings with diameter 102, 114, 120 and 140 mm are run in consisting of
flush-joint pipes.