Method and installation of the drilling and of the lining of a well, in particular of a borehole petrolier, by means of a flexible tubular edge initially, and cured in situ

摘要

A process for drilling and lining a shaft, particularly an oil exploration shaft, using an assembly of initially flexible preformed sections which are unfoldable radially in the shaft, under internal pressure to form a cylinder and to be rigidified in situ by polymerisation of the wall comprises: (a) using preforms which maximum cross section when folded is less than the internal diameter in their unfolded state, and having an end section with a slightly larger diameter after unfolding than that of the rest of the preform, allowing butt joints which cover this end section; (b) placing a first preform near the entrance to the shaft with its larger end turned downwards in the shaft; (c) passing a drill tool downwards through this section and drilling the area below to make a hole of a size and shape that will receive the next section; (d) removing the drill tool; (e) introducing a folded preform through the section already in place and positioning in the hole so its top edge is inside the enlarged part of the previous section; (e) pumping in a fluid cement and forcing the cement back upwards around the preform against the wall of the hole using a fluid under pressure with a density greater than that of the cement pumped into the preform to unfold it radially from bottom to top; (f) maintaining the pressure and heating the wall for polymerisation; (g) retrieving the tools used for the operation once the sections are well in place; and (h) repeating the above operation until the required length of shaft is obtained. Also claimed is an installation to carry out this process, comprising at the head of the shaft: a storage bobbin for the rolled preforms, a head above the shaft to guide and introduce both the preforms and the various tools into the shaft; bobbins for the flexible metal tubes which raise and lower the various tools; one of which carries an electricity supply; and an electrical generator.