COMPOSITION OF FOAMED CRYOGEL AND METHOD OF FORMING IT Russian patent published in 2008 - IPC C08L29/04 C08J9/10 C08K3/16 C08K3/04 

FIELD: composition of foamed cryogel containing polyvinyl alcohol, sodium chloride, sodium nitrite, ammonium chloride, carbon black and water.

SUBSTANCE: foamed cryogel is formed by chemical foaming with the aid of nitrogen separating-out during oxidizing-reducing reaction between equimolar amount of sodium nitrite and ammonium chloride followed by freezing-defreezing cycle. Proposed foamed cryogel possesses improved thermo-physical and mechanical properties required for heat insulation of producing well mouth and avoidance of precipitation of paraffin deposits. Foaming of starting material is carried out chemically, thus forming finely-dispersed high-expansion foam; in the course of exothermic reaction, heat is released, thus enhancing homogenization of starting polymer solution; presence of sodium chloride hardens foamed cryogel and rises its melting point. Foamed cryogel thus obtained may be used in construction engineering and installation of equipment in oil and gas wells of North regions, as well as recultivation of soils in cryolite zones and technological processes of oil production and transportation.

EFFECT: improved thermo-physical and mechanical properties of product.

3 cl, 1 tbl, 9 ex