Once pressure below the plug was relieved and the well was killed, the
operator used a rig to pull the remaining bridge plug and latch onto the 3
1/2-in tubing. From there, a 1 1/4-in CT unit was deployed to drill out the
cement plug in the 3 1/2-in tubing, displace the well to water-base mud, and
place new cement plugs to reabandon the well.
Operator removed plugs in 3 days instead of several additional
days
Unlike rig joint pipe operations, CT work can be conducted in live
wells without having to overestimate the hydrostatic pressure required to
overcome potential trapped pressure behind a plug. Large-OD CT pipe in
conjunction with CoilTOOLS tools and solutions’ ruggedized milling and
bridge plug coring assemblies enabled successful reabandonment in large casing
while maintaining pressure control, where previously the operator had only used
jointed pipe. Therefore, Coil Tubing Services was able to remove the surface
cement plug and core through the bridge plug as planned in less than 72 hours.
Similar operations with joint pipe in a rig would have lasted several
additional days with a higher HSE risk exposure. The well was reabandoned in
compliance with federal regulations.