A method for removing from a terrain a buried pipe portion of a substantially cylindrical pipe made of a ductile material and suitable for use in pipelines including oil pipelines, water pipelines, and gas pipelines, which method comprises steps of:
- a) digging at least a first excavation in the terrain, at a first longitudinal end of the buried pipe portion to be removed, to make the first longitudinal end accessible;
- b) making in a wall of the buried pipe portion to be removed, through-cuts having a helical form with respect to a central longitudinal axis of the buried pipe portion to be removed so as to form helical strips;
- c) taking the helical strips and removing the helical strips from the terrain, passing the helical strips through the first excavation;
- and
- d) obstructing an underground volume that contained the removed helical strips and the first excavation with filler material which is initially fluid, and is able to solidify over time,
- wherein during step (a) a second excavation is made at a second longitudinal end of the buried pipe portion to be removed;
- wherein, before performing step (b), the following steps are carried out:
- providing an obturating means having a width that is equal to a width of a section of the buried pipe portion to be removed and having a respective length;
- making at least one through-cut in a wall of the section of the buried pipe portion to be removed, at a position to be obstructed by the obturating means, wherein the at least one through-cut has a length that is equal at least to an effective or operative length of the obturating means;
- and
- inserting the obturating means in the buried pipe portion to be removed, placing the obturating means at the position of the section of the buried pipe portion to be removed at which the at least one through-cut has been made, activating the obturating means such that obturating means adhere to the internal surface of the pipe to sealingly obstruct the section of the buried pipe portion to be removed and to define, in the buried pipe portion to be removed, a first volume and a second volume that are fluid-dynamically isolated from each other by means of the obturating means;
- and wherein
- a first part of step (b) is carried out by making a closed through-cut, which intersects said at least one through-cut made at the section of the buried pipe portion to be removed obstructed by the obturating means, to section the buried pipe portion to be removed by separating a part thereof which contains the first longitudinal end and is coextensive with the first volume from a part which contains the second longitudinal end and is coextensive with the second volume and the section of the buried pipe portion to be removed which is obstructed by the obturating means;
- thereafter, the first part of step (b) further includes making at least an additional through-cut on the wall circumscribing said first volume, the additional through-cut extending from said closed through-cut to the first longitudinal end, thereby forming one of said helical strips, the additional through-cut being one of the through-cuts having a helical form;
- thereafter, filler fluid is poured into the first volume and, at the same time or subsequently, a first part of step (c) is carried out, wherein the one of said helical strips obtained in the first part of step (b) is removed from the terrain;
- thereafter, a second part of step (b) is carried out, in which at least a further through-cut is made on the wall which circumscribes the second volume, the further through-cut extending from the closed through-cut to the second longitudinal end, thereby obtaining a further one of said helical strips, the further through-cut being another one of the through-cuts having a helical form;
- and
- thereafter, the obturating means is removed from the buried pipe portion to be removed, by being passed through the second longitudinal end;
- and then
- a second part of step (c) is carried out, in which the further one of said helical strips is removed from the terrain and, at the same time or subsequently, filler fluid is poured into the second volume.