Метод контроля диэлектрической сплошности внутреннего защитного полимерного покрытия труб нефтяного сортамента после поперечного изгиба с заданной стрелой прогиба при приемо-сдаточных испытаниях у производителя и при опытно-промышленных испытаниях на промысловых полигонах у потребителя

The article notes that the internal insulation of OCTG with a protective polymer coating is a promising direction of improved energy efficiency, reliability, safety, and manufacturability of field pipelines, tubing, casing and drill pipes made of these tubular goods. It is stated that one of the important characteristics of the inner protective polymer coating is its dielectric continuity, characterizing the absence of cross-cutting faults. An indicator of the continuity of the dielectric protective polymer coating is the absence of its electrical breakdown at a given voltage value. This coating must possess dielectric continuity, not only in the initial state, but also at various external influences during storage and transportation stages of pipes with inner protective polymer coating, installation and operation of field lines or tubing of pipes in boreholes of these pipes. The most dangerous type of external influences that can disrupt the continuity of the inner dielectric polymer coating is a lateral bending of pipes at the above stages of their life cycle. This leads to the need for control over dielectric continuity of pipes internal polymer coating after lateral bending with the required bending deflection by the manufacturer and consumer of oil country tubular goods with inner protective polymer coating. Currently, domestic enterprises do not test internal insulation of OCTG with polymer coatings due to lack of appropriate methods and technical means of control. To solve this problem the laboratory of polymeric coatings engineering for oil and gas equipment and facilities of Gubkin Russian State University of Oil and Gas designed the unit and control procedure for dielectric continuity of inner polymer coating of steel OCTG after lateral bending with a specified bending deflection at the factory during the acceptance and delivery tests and at pipe yards of oil companies after pilot tests at commercial sites. The introduction of this control method will significantly improve the reliability of field pipelines, tubing, casing and drill pipes with protective coatings.