Experimental studies of operational properties of asphaltene-resin-wax deposits formed in oil trunk pipelines

The paper presents the results of experimental laboratory studies of the properties of asphaltene-resin-wax deposits (ARWD) affecting the efficiency and reliability of pumping. The analysis of negative and positive properties of deposits, including corrosion impact of ARWD on the oil pipeline wall, was carried out. The thermal conductivity coefficient of heavy oil deposits samples taken from existing oil trunk pipelines (OTP) was measured. To assess the influence of the deposit layer on the smoothness of the inner surface of the pipe wall, tests were carried out to determine the roughness coefficient using the samples of pipe spool segments. The samples were cut from the sections of OTP under repair, the inner surface of which is covered with a layer of ARWD, accumulated and hardened during the long-term operation of pipelines, periodically affected by in-line cleaning pigs. The results of laboratory studies of the ARWD thermophysical properties confirmed the relatively high thermal insulation properties and smoothing ability of the deposit layer. Tests to assess the corrosion properties of ARWD showed the possibility of reducing the corrosion rate due to the passive protection of the deposit layer formed on the inner surface of the pipe wall.