PROPERTIES OF WATER-SWELLABLE COMPOUNDS BASED ON NITRILE RUBBER WITH VARIED ACRYLONITRILE CONTENT
This article examines the development of water-swellable rubbers for oil and gas production packer equipment. The object of the investigation is to document the effect of rubber's acrylonitrile content on the swelling of the elastomers modified with sodium-carboxymethyl cellulose and a copolymer of acrylamide and potassium acrylate. After testing the samples at room temperature, the most influential factor in a material's swelling was discovered to be the mineral content in the liquids imitating well fluids. NBR polarity stemming from the inherent acrylonitrile (CN-group) level was not explicitly detected to affect the swelling rate and maximum ratio under the described conditions of the experiment. It was determined that in sodium chloride aqueous solutions with concentrations from 3 to 22%, swelling of nitrile rubber mostly depends on its cross-linking degree.ABSTRACT
Mass change in elastomer samples with different contents of acrylonitrile units against their water-swelling time.
Dependence of the rubber mass change at the exposure in (a) 3.5%, (b) 6%, (c) 10%, and (d) 22% aqueous solution of sodium chloride on content of acrylonitrile chains in the elastomer.
Dependence of (a) tensile strength and (b) elongation at break of the rubbers at 7 days' exposure in water and aqueous solutions of sodium chloride on content of acrylonitrile chains in the elastomer.
Photo of a disk-shaped WSR (CN-28) sample before its contact with fluids.
Change of the (a) volume and (b) diameter of the of the disk-shaped rubber (CN-28) sample during its exposure in water and aqueous solutions of sodium chloride.
Photos of the WSR (CN-28) samples after (a) 7 days and (b) 30 days of exposure in water and an aqueous solution of sodium chloride.
Contributor Notes