Patent ID: 6196766
Filing Date: 2001-03-06
Classification: E02F,E21B,F16L

Abstract:
An apparatus adapted for movement through a passage formed in the ground, comprising:an elongate element having an inner channel and an outer channel, the inner channel being a region internal to an inner longitudinal periphery and the outer channel being a region between the inner longitudinal periphery and an external longitudinal periphery of the elongate element;a shroud;means for positioning the shroud around at least part of the external longitudinal periphery of the elongate element for supporting engagement with the periphery of the passage to provide a space through which the elongate element can move, the shroud being of flexible construction and being arranged to be progressively installed in position as the elongate element moves along the passage; andmeans for introducing an inflation fluid into a region between the shroud and the external longitudinal periphery of the elongate element for inflating the shroud and maintaining it in supporting engagement with the periphery of the passage, wherein the shroud is delivered to the elongate element from a remote storage point for installation.