METHOD FOR TEMPORARY ISOLATION OF WELL INTERVAL, METHOD OF REPEATED HYDRAULIC FRACTURING OF FORMATION AND WELL KILLING METHOD Russian patent published in 2021 - IPC E21B43/267 E21B43/14 E21B33/12 C09K8/92 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: group of inventions relates to oil and gas industry and can be used in stimulating a subterranean formation by hydraulic fracturing operations, in particular during temporary isolation of fractures of hydraulic fracturing of formation, in repeated hydraulic fracturing of formation, as well as in killing wells. Method of temporary isolation of a well interval includes pumping to the well of the first suspension containing a viscous carrier fluid, degradable particles and degradable fibres till formation of the first filtering layer. Second suspension containing a viscous carrier liquid, nondegradable particles and degradable fibres is pumped into the well until a second filtering layer is formed. First and second suspensions are not mixed when pumped into the well. For optimum isolation of the volume, the volume of the first suspension relates to the volume of the second suspension in ratio of 1:5 to 2:1. Also, a method of repeated hydraulic fracturing is proposed in the interval with several fractures of HF and method of merciful killing of the well.

EFFECT: technical result is reduction of formation colmatation and degradation of formed insulating layer.

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