METHOD FOR SEALING BROKEN COLUMN IN A WELL Russian patent published in 2004 - IPC

FIELD: well maintenance technology.

SUBSTANCE: method includes lowering device into the well, directing said device towards broken portion, pumping cementing solution behind broken column, time delay until cementing solution hardens. Device used in the process includes directing localizing assembly, shell with swelling substance and perforated tail piece. Device is directed with possible fixing of directing localizing assembly and shell with swelling substance in the column below breach zone and overlapping of the very broken portion by tail piece with localization of lower and upper portions of column. After expansion of shell with swelling substance and mating of said shell with column tool is dismounted from perforated tail piece and is raised onto the surface. Pumping of cementing solution behind broken column is performed through perforation of tail piece after raising tool onto surface and lowering of another tool into the well. During drilling of remaining cement stone within the column also drilled are remains of stone in tail piece, ends of shell, swelling substance from the shell and directing localizing assembly.

EFFECT: restored passability of tool, liquidated depressurization of column with the well back in operation.

3 dwg