METHOD FOR WELL REPAIR Russian patent published in 2009 - IPC E21B29/10 E21B33/13 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil industry and may find application in well repair. Provides for increased reliability of well repair. According to method, specific injection capacity is defined for deformations of casing string. Plaster is used to close deformation with specific injection of more than 2 m³/(hour MPa). For repair of deformation with specific injection capacity of at least 2 m³/(hour MPa), additional casing string of lower diametre is lowered, having toothed nozzle at the end, at that teeth are inclined inside by value of more than plaster wall thickness. Cement mortar is pumped through additional casing string in case of its lowering for the entire depth with its rising in annular space down to the depth that is by 10-50 m less than level of cement ring in well annular space, or in case of additional casing string lowering down to intermediate depth, cement grout is pumped with its rising to the head of additional casing string.

EFFECT: increased reliability of well repair.

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