FLUTe liners are delivered to the site on a shipping reel with the liner wound inside out (Figure 1). The open end of the liner is clamped to the wellhead and the liner is then pushed inside the casing a foot or so to create a small pocket. Water is then added to the pocket to a level above the water table of the formation, creating a driving pressure on the bottom end of the liner.
The driving pressure (typically 5 to 10 feet of water pressure) allows the liner to propagate down the borehole (a process called eversion), displacing the borehole water into open flow paths and seals the liner firmly to the borehole wall (Animation 1).
Figure 1. Liner on Shipping Reel
Figure 2. Water Addition to the liner
The pressure exerted by the liner on the borehole wall is very strong and seals off all fracture flows in the borehole (Video 1).
The driving pressure needed to evert the liner down the borehole mainly depends on the head of the formation. For high head or artesian conditions differential pressure can be achieved by the addition of higher density muds to the interior of the liner or by the use of stand pipes and elevated platforms during installation.
Video 1. Liner Sealing Quality
Animation 1. Liner Eversion