Optimization diagram of electric heating cable for coal methane head system

Published on:

2023-01-05 08:43

Compared to conventional gas fields, the biggest difference in the development of coal-bed methane deposits is that in the initial phase of production, the coal-bed methane deposit is first drained and then produced. Therefore, the MPC production pipeline contains a certain amount of water. To avoid freezing and blocking of wellhead pipelines, it is necessary to conduct electric heating and conservation of ground wellhead gas and drainage pipelines in single wells and well wells.

The coal seam methane field in the Huabei oil field used electric heating to heat coal bed methane well pipelines. Compared with the hot water heating process, it reduces energy loss and greatly saves investment in the construction of the surface collection and transportation system of the coal seam methane deposit.

There are three common methods for electric heating pipelines: induction electric heating (high cost), skin effect method (suitable for trunk pipelines), and resistance heating method. The resistive heating method is widely used because of its low investment and wide application conditions. From the initial phase of development until 2018, 60 watt constant power electrical cables were used to heat the pipeline of the coal seam methane field. The constant power electric heating cable is a kind of resistance heating method. This kind of constant power electric heating cable consumes a lot of energy, which is not conducive to cost control. Need to optimize and update.

In electric heating and electric heating, resistors are used to generate heat to compensate for the thermal losses of the pipeline. According to the principle of electric heating, electric heating cables with resistors can be divided into constant power electric heating cables and self-limiting temperature electric heating cables. Although they have the same heating principle, they still have different applications.

As the electric heating cable in the coal seam methane deposit is used to heat and insulate the outer wellhead pipeline of the coal seam methane deposit, it is greatly affected by the outside air temperature, that is, the temperature difference between day and night. Compared with constant power electric heating cables, warm electric heating cables are more suitable for use in such working conditions.

To summarize, it can be said that the coal seam methane deposit has chosen our self-limiting temperature electric heating cable while optimizing the electric heating cable. Pipelines in this coal seam methane deposit are metal pipes using 20 # seamless steel pipes; single wells and coalbed methane wells typically use D60x3.5 pipelines for the drilling site and D89x4 for horizontal wells; gas inside the pipelines maintains a temperature of 15 °C, and the external environment is the lowest. The temperature is-30 °C and the maximum temperature difference is 45 °C. Therefore, we use DN50 pipes for 15 W electric heating cables and 20 W for DN80 pipes.

The internal (external) gas well pipelines in this coal bed methane field are often heated by self-regulating electric heating cables. After more than three years of on-site operation, there is a good electric heating effect, which not only meets the requirements for the safe extraction of coal seam methane, but also significantly reduces the cost of coal seam methane extraction and operation, and saves investment in engineering. Construction, which gives a good economic effect.

Latest News

Please search according to your needs.