COMPOSITION OF SWELLABLE PACKER WITH RESPONSE DELAY Russian patent published in 2017 - IPC C09K8/44 C09K8/512 E21B33/12 C08L9/02 

FIELD: chemistry.

SUBSTANCE: borehole sealant with a controlled swelling speed is described, which contains a composition comprising: a polymer comprising a nitrile-based polymer or ethylene-propylene-diene copolymer rubber; an absorbent, wherein this absorbent comprises an acrylic copolymer; a primary cross-linked network structure comprising primary bonds between the polymer chains; and a secondary cross-linked network structure including secondary bonds between the absorbent molecules, wherein the secondary bonds are formed by a crosslinking reagent comprising titanate, zirconate, aminocarboxylic acid, metal chelate, borate, ketal or a combination thereof, and wherein the secondary bonds are destroyed by varying the value of pH, temperature, pressure, salinity, or a combination thereof, while the primary bonds remain unaffected under the same conditions; and wherein the sealant swells and seals the bore as a result of destruction of the secondary cross-linked network structure. A method for controlling the swelling speed of a borehole sealant, a composition for forming a borehole sealant, a system for sealing a wellbore, and a borehole sealant with a controlled swelling speed are also described.

EFFECT: borehole sealant with an adjustable swelling speed is obtained.

39 cl, 9 dwg