Application and research progress of the active heat tracing and insulation technology of subsea pipeline

The active heat tracing and insulation technology of subsea pipeline, as a supplement to the passive thermal insulation, will be applied to the development of offshore high viscosity and low pour-point oil and deep-water oil and gas in China. At present, however, the application of independently developed active heat tracing and insulation technology of subsea pipeline is still blank in China. Therefore, it is necessary to analyze and compare domestic and foreign application cases and learn the advanced practices from them. It is indicated from the investigation and analysis that the active heat tracing and insulation technology of subsea pipeline is suitable for the sea areas in different depths, but currently its application mainly focuses on the North Sea which is shallow-water area. Due to its strong adaptability and high heat efficiency, electric heating/heat tracing technology, especially the indirect electric heat tracing technology will certainly replace the hot fluid heat tracing technology. Compared with the direct electric heating technology, the indirect electric heat tracing technology is more efficient, stabler and safer and can be used for long-term operation, so it is more suitable for offshore oil and gas transportation. As a kind of indirect electric heat tracing technology, the skin-effect electric tracing is the main development direction in the future for it is of high safety and heat efficiency and its temperature along the pipeline is uniformly distributed and controllable, so it is suitable for the heat tracing and insulation of long-distance subsea pipelines. In the background that the China's government provides powerful support for important equipment localization, it is necessary to carry out horizontal and vertical comparisons on domestic active heat tracing and insulation technology of subsea pipeline and intensify its applied research to break through the key issues (e.g. the reliability of the connection point at the junction box) so as to realize the localization of skin-effect heat tracing technology of subsea pipeline as soon as possible and provide technical support for the sustainable development of offshore oil and gas fields in China.