Research on corrosion detection method of pipeline under thermal insulation with heat trace wire

Abstract

In the process of transporting crude oil, especially heavy oil, in submarine pipelines, hydrate formation, wax precipitation and viscosity increase often occur due to the decrease of temperature, which directly affects oil and gas transportation and may seriously lead to pipeline blockage and production of oil and gas fields. In order to maintain the temperature in the pipeline during production operation and shutdown, it is usually necessary to take insulation measures for the submarine pipeline. However, during the operation of the equipment, corrosion under the thermal insulation layer often occurs, and even leakage accidents may occur in serious cases, seriously threatening the safe and stable operation of the device. Therefore, we use the transient electromagnetic method to detect the corrosion of the pipeline under the thermal insulation layer. However, pipeline insulation is usually heated by an electric tracing system to maintain the temperature of the pipeline surface. Since the tracing core is made of metal material, the electric tracing system always exists in the detection process, which will affect the detection signal of pulsed eddy current pipeline and affect the detection performance of the detection system for pipeline corrosion detection under the thermal insulation layer. In order to solve this problem, a method of pipeline corrosion detection under thermal insulation with trace wire is proposed in this paper. By establishing the corrosion detection model of the pipeline under the insulation layer with heat trace wire, the influence of trace wire on the detection system is compared and analyzed, and the winding direction and winding position of trace wire can be clearly identified, which provides a basis for further analysis of the pipeline situation.