External Casing Packers (ECP’s) are built with a large internal diameter, allowing them to be slipped onto a casing joint and secured using high strength, filled epoxy resin. This design provides a means of installing without welding or threading.
Packers are inflated by a small control line run on the outside of the casing, so there’s no holes in the casing due to port collars or the like.
Owing to the usual applications for these packers being shallow gas isolation, operating pressures are generally kept below 500 psi. A fixed end packer design is employed to simplify construction whilst still providing a high integrity sealing system.
Sliding end packer designs can be employed where large expansion or higher differential pressure capacities are required.