METHOD OF SEALING WALLS OF WELLS Russian patent published in 2009 - IPC E21B29/00 

FIELD: oil and gas production.

SUBSTANCE: invention refers to oil and gas producing industries, particularly to methods of sealing casing column and shutting-off reservoirs. The method consists in lowering a patch in kind of a flat metallic branch with elastic sealing on ends and an anchor in form of a lengthwise corrugated branch, in boosting excessive pressure inside the patch till goffers of the anchor melt and be pressed tightly to walls of the well, in exerting rotation to a setting tool with an expanding mandrel, till patch walls are tight and leak proof pressed. The patch is lowered on a flow string equipped from below with a hollow plug and with the setting tool located lower; the setting tool has an expanding mandrel in form of a rolling head with alternated projection of rollers. Before lowering the plug is connected to the upper end of the patch overlapping it leak proof along perimetre; the lower end of the patch is leak proof overlapped with a bearing plate. Upon installation of the anchor the plug is detached from the patch and is extracted from it together with the setting tool. During expanding the setting tool is additionally axially displaced downward, and lower end of the patch is depressurised at the end of expansion.

EFFECT: simplified implementation of method and increased reliability.

3 cl, 3 dwg