METHOD FOR REMOVAL OF CASINGS IN AN UNDERGROUND WELL

摘要

A method of removing casing (3) from a well (1) is described, the method including the following steps: (A) setting a first sealing element (11) into fluid-sealing engagement with the inside of the casing (3); (B) lowering a flow-through string (9) into the well, a cutting tool (93) and a second, reversibly expandable sealing element (91) being connected to the string (9); (C) forming perforations (31) into the casing (3) by means of said cutting tool (93); (D) expanding the second, expandable sealing element (91) into fluid-sealing engagement with the inside of the casing (3); (E) passing a pressurized fluid (95) through the string (9) and into the annulus (5) via the perforations (31), so that the viscous and/or solid mass (55) is displaced up the annulus (5); (F) cutting the casing (3) around its entire circumference; and (G) pulling a length (L1) of the casing (3) up from the well (1).