Electric heat tracing bands are used for natural gas extraction

In the natural gas industry, electric heat tracing technology has become a crucial infrastructure for ensuring production safety and stable supply. Through active heat compensation, it precisely addresses the severe challenges posed by low temperatures throughout the entire process of natural gas extraction, gathering, transportation, and processing, especially for the most intractable issue of "hydrate ice blockage".

Addressing hydrate ice blockage is the core motivation for the natural gas industry to adopt electric heat tracing. When high-pressure natural gas expands violently and absorbs heat in pipelines and valves due to a sudden pressure drop (i.e., Joule-Thomson effect), the temperature drops below the critical point for hydrate formation. At this point, trace amounts of water vapor in the gas stream condense into ice or white crystalline natural gas hydrates, blocking equipment and threatening pipeline safety. The electric heat tracing system can maintain the pipe wall temperature at a safe level above the water dew point by continuously and uniformly compensating for heat loss in the pipeline, effectively inhibiting hydrate formation.

Mining process: Wellhead antifreeze is the first line of defense

At the forefront of natural gas extraction, wellhead equipment serves as the first line of defense to ensure stable gas supply. In winter, when temperatures are low, valves, gas transmission pipelines, and instrument pressure conduits are highly susceptible to freezing due to water vapor, potentially leading to equipment malfunction or even production shutdown. By wrapping self-regulating electric heat tracing bands (maintaining a temperature of 5-15°C) around wellhead valves and laying flat heat tracing on instrument housings, equipment freeze-blocking can be effectively avoided. Taking the shale oil block of Daqing Oilfield as an example, it has formulated a "one well, one strategy" cold prevention plan, installing wellhead electric heat tracing bands and process pipeline insulation layers for low-temperature wells, thus building a "cold prevention wall" for production from the source. Since natural gas is a flammable and explosive substance, the electric heat tracing bands must be of explosion-proof type, with its metal shielding layer serving as a reliable grounding wire to effectively eliminate static electricity accumulation.

Gathering and transmission link: ensuring the smooth flow of the "blood vessels" of the pipeline network

Entering the gathering and transmission stage, natural gas pipelines face a long-term low-temperature test. Under the traditional operation and maintenance mode, electric heat tracing equipment requires manual foot patrol inspection, which is not only time-consuming and laborious but also poses a risk of missed inspection leading to pipeline freeze-up and blockage. Taking the CNOOC Bozhong 19-6 condensate gas field as an example, since winter, a comprehensive investigation has been conducted on 1,912 electric heat tracing circuits, adopting a "digital inspection + manual re-inspection" mode to ensure stable natural gas export during winter. In terms of model selection, for natural gas pipelines prone to condensation, priority is given to using constant power electric heat tracing bands with a power of 20-25W/m to ensure stable heat; for short-distance branches, temperature-limiting models are selected to automatically control temperature and prevent overheating. Buried natural gas pipelines can also supplement heat loss in pipelines, pipe bodies, and equipment through electric heat tracing systems, thereby preventing pipeline blockage. After using electric heat tracing, the pipeline outlet temperature can be increased by at least 3.8℃ and up to 19.8℃ in calculations, with significant effects.

Processing stage: precise temperature control for pressure regulation and dehydration

In natural gas processing plants and distribution stations, pressure regulation and dehydration are the links with the highest risk of ice blockage. When high-pressure natural gas flows through the throttling components of the pressure regulator, severe pressure drop and volume expansion absorb a large amount of heat, leading to a sharp drop in temperature around the valve body. The accumulation of ice may directly result in the loss of pressure regulation function. By closely laying explosion-proof self-regulating electric heat tracing bands on the outer walls of the pressure regulator valve body and upstream pipe sections, combined with insulation material wrapping, the temperature drop caused by gas pressure reduction can be effectively offset, ensuring that the surface of key components remains above freezing point at all times. In core process equipment such as molecular sieve dehydration systems, electric heat tracing bands are also laid on the surface of regeneration gas pipelines to compensate for heat loss and ensure efficient dehydration and regeneration efficiency. To eliminate management blind spots, the Zepu Oil and Gas Production Management Area of Tarim Oilfield has developed a centralized acquisition and fault warning system for electric heat tracing conditions. This system can capture core parameters such as current, voltage, and power in real time and transmit them synchronously to the main control room, improving inspection efficiency by more than 35% and completely solving the problems of missed inspections and electric shock hazards.