STUDY OF THE DISPERSE EFFECT OF POLYMERIC SURFACE-ACTIVE SUBSTANCES IN ACRYLIC DISPERSIONS USED FOR PAINTING OIL WELL ARMATURE

Abstract

The relevance of the work is caused by the need to develop new environmentally friendly water-dispersed paints with increased operating life, according to the strict requirements of PJSC «Rosneft» to protect wellhead valves of oil wells against atmospheric corrosion. In modern practice of corrosion protection of wellhead valves in oil and gas wells and pipelines protection from damaging effects of atmospheric environments the paint and varnish based insulating coatings are widespread. Due to the tightening of environmental requirements in many countries, the use of water-based coatings has increased. So one of the largest manufacturer of wellhead valves of oil wells in the Republic of Kazakhstan – JSC «Kazneftegazmash» – uses acrylic coatings: primer «Unikor-M» TU 2316-002-0-31953544-96 and paint «Akrem-Metal» TU 2316-003-0-31953544-96, for painting their products waterborne. However, the main Russian oil and gas companies, in particular Rosneft, Gazprom and others, recently sharply tightened the requirements for the term of protective resource of paint coatings. Thus, according to the technological instruction of PJSC «Rosneft» № P2-05 TI-0002 «Anticorrosion protection of metal structures at oil and gas production facilities, oil and gas processing and oil products supply of the company» the minimum protective resource of paint coatings, depending on the operating conditions, is not less than 10 years. And the acrylic water-soluble coatings used by JSC «Kazneftegazmash» provide a protective resource of coatings, depending on the operating conditions, not more than 5 years. Therefore, we have attempted to increase the time of protective resource of the paint coating by obtaining a more uniform/dispersed distribution of the pigment in the polymer matrix, through the use of surfactants. The main aim of the study was to increase the protective resource of acrylic paint, based on the study of the influence of polymer surfactants (surfactants) on dispersion of pigment (titanium dioxide) in the aqueous dispersion of acrylic polymer. Methods: computer-optical microscopy and mathematical modeling. Results. The paper introduces the results of the study of the effect of TEGO polymer surfactants: Glide 100 (polyether-siloxane copolymer) and Dispers715w (sodium polyacrylate), on titanium dioxide (grade R-02) dispersion in aqueous acrylic composition. It was shown that Glide 100 and Dispers 715w with a content of 0,25 to 0,5 g/dm3 in the composition improve pigment dispersion. The most effective additive is Dispers 715w, while the diameter of the pigment particles is reduced almost twice (from 8 to 4 microns). The authors have derived the equations describing the influence of content and type of surfactant on the particle diameter of the pigment, and based on the equations built the nomograms. The obtained coatings are characterized by more dispersed distribution of the filler in the polymer matrix, which significantly increases the protective resource of the paint material. The developed coatings can be used for painting wellhead valves of oil wells.

Keywords

• protective coatings
• coatings
• protection of oil well armature from corrosion
• surface-active substances
• dispersion
• water-acrylic dispersion
• titanium dioxide
• suspension