Bentonite Sleeve Seal
Bentonite seals are used above the PrePak screen to ensure placement of a water tight seal without relying on pouring or pumping sealing materials down the small space between the casing and borehole. The sleeve seal consists of granular bentonite clay pre-packaged around a short, flush-threaded casing section. The section is installed above the screen in the casing string. When lowered into position, the bentonite hydrates and swells to form a water tight seal between the casing and the borehole.