Patent attributes
A system and method for performing a flexible liner inversion out from a low-permeability borehole. A flexible liner may be installed by eversion down a subterranean borehole to selectively seal the borehole. Such a liner may be removed from the borehole by inverting it up the borehole. Water is added into the borehole beneath the lowest end of the liner, to permit or facilitate inversion of the liner. Water is allowed to flow from the interior of the liner to the borehole space beneath the liner, thereby raising the pressure in the unsealed borehole beneath the liner, and thereby allowing the liner to be further inverted upward. By allowing water to flow from the liner interior to a borehole volume beneath the liner, the need for a long vent or pumping tube is avoided.
