METHODS FOR TREATING SUBTERRANEAN WELL Russian patent published in 2018 - IPC E21B43/22 E21B43/267 C09K8/80 C09K8/92 

FIELD: chemistry.

SUBSTANCE: present invention relates to compositions and methods for maintaining control of a well during a major overhaul. Method of treating a subterranean well during a well repair process, comprising steps of: preparing a composition comprising water, at least one water-soluble polymer, particles and degradable fibres, placing the composition in the borehole such that the composition contacts a slotted liner, a downhole filter, perforations, or combinations thereof, allowing the composition to flow into the liner, filter or perforation, whereby the particles and fibres form at least one plug or a filter cake, or both, which withstand differential pressure higher than 3.5 MPa, which prevents further fluid movement through the liner, filter or perforations, allowing the fibres to degrade, thereby causing the plug or filter cake or plug or both to weaken, and removing the plug or filter cake or both, thereby re-establishing fluid movement through the liner filter or perforations. Invention is developed in dependent items of the formula.

EFFECT: technical result is an increase in processing efficiency.

14 cl, 3 ex, 6 dwg