RUBBER MIXTURE FOR THE CUFF OF A PACKER APPARATUS, SWELLING IN THE "POLYEMULSAN" DRILLING FLUID Russian patent published in 2022 - IPC C08L101/14 E21B33/12 C08L7/00 C08L23/16 C08L9/02 C08K3/11 C08K3/06 C08K9/10 

FIELD: rubbers.

SUBSTANCE: invention relates to the rubber industry, in particular, to creation of a rubber mixture for manufacturing rubber cuffs of packer apparatuses swelling in the "Polyemulsan" drilling fluid. The rubber mixture for manufacturing rubber cuffs swelling in "Polyemulsan" drilling fluid, based a combination of natural rubber and BNKS-18 butadiene nitrile rubber comprises target supplements, including chrysotile asbestos dispersed in a melt of ε-caprolactam with para-phenylenediamine derivatives, the dispersion whereof is, in turn, dispersed in double ethylene propylene or triple ethylene propylene diene rubbers, and sulphur as a vulcanising agent, wherein the sulphur in a paste with the dispersion medium represented by a eutectic melt of ε-caprolactam and maleic acid, is enclosed in a capsule with a colloidal silica shell with the following ratio of components of the sulphuric capsule, wt.%: sulphur 22.50 to 27.50, colloidal silica (BS-120) 50.00, ε-caprolactam 13.50 to 16.5, maleic acid 9.00 to 11.00, wherein the sulphur capsule with the following content of the main components of the mixture, wt. pts.: BNKS-18 rubber 50.00, natural rubber 50.00, dispersion of ethylene propylene or ethylene propylene diene rubber with dispersed chrysotile asbestos 130.00, sulphur capsule 3.64 to 4.44.

EFFECT: invention provides a possibility of creating a rubber mixture providing an increase in the diameter for the cuffs of packer apparatuses placed in polyemulsan with a temperature of 8 to 12°C by no more than 10% after 10 days of swelling, and no less than 30% after 60 days, and, to a greater extent, preserving said properties in the swollen state.

1 cl, 4 tbl, 3 dwg, 12 ex