Model GL packer is an isolation packer used in multiple gravel pack tool systems, it has a simple structure that allows it to be set by hydraulic pressure and released by pulling up.
Multiple GL packers could be used in a completion string to isolate perforated zones. In many cases it is used in combination with model FS packer as the ‘middle’ packer of the string, a service tool is run in position to set the GL packers before gravel packing certain zones. A seal bore extension must be connected to create the pressure sealing to set the packer.
GL packer could be also used for water shut-off, and other isolation purpose.