This is a prefectly do-able task, displacing the liner with a
different fluid has been done many times with conventional liner
hanger equipment. In our opinion best practice would be the
following. Run an extra float collar in addition to standard float
collar and double valve float shoe, providing extra assurance of no
back flow after cement job. Use a liner wiper plug with latch-in
lock down feature, for extra back-flow assurance, and run an extra
joint or two of shoe track to increase probability of bumping plug.
Ensure liner hanger running tools and retrievable pack-off or swab
cup seal assembly is pressure tested to 1.5 times the expected back-
pressure expected on the job. Ensure sufficient wieght is available
to set-down on liner top packer without buckling pipe, use HWDP
above liner hanger, and/or a rotating packer actuactor type setting
tool. Most conventional liner hanger supply companies will have
access to all of these devices. If you see clear indications of your
liner top packer setting you could reverse circulate any excess
cement out monitoring for losses very carefully, which could be down
the inside or down the outside of the liner. If you do not see clear
indications of the packer setting consider leaving cement on top,
and doing a clean out run, or circulate any excess cement out the
long way (no usually practical on a semi/drillship). Regardless of
method of circulating out be sure to move the pipe regularly.
In addition, run a disposable clean-up tool as part of the liner
hanger assembly to clean the casing on the way in the hole and
particularly the packer/hanger setting area. Run an additional
disposable clean-up tool on the tail pipe of the completion string
to clean the casing again on the way in and the packer setting area.
for more information on this type of tool please contact me directly
on [email protected]
We believe the industry can move toward eliminating costly and time
consuming deep dedicated wellbore clean-up and displacement runs in
some appropriate circumstances and the type of operation you are
embarking upon is a good candidate for this.