| With the increase of the deep prospecting work and the development of the scientific deep drilling, the requirements of casing wall protection technology are much higher than before. The traditional methods of wall protection all have showed more and more obvious limitations. Hot-melt casing wall protection technology is that the heat generated by electric melting device melts hot-melt gelling materials with low melting point, the materials adhere onto the wall around the hole after pressing action by short section called molding equipment. After the temperature cooling down, the hot-melt material forms a dense protective layer that can protect the stability of the hole.This paper based on the hot-melt casing wall protection technology,making an analysis on advantages and disadvantages of the materials of heating element in the hot-melt head and choosing a kind of better electrical heating material; making a comparison analysis on the heat efficiency of the heat element with different structures by the ANSYS simulation analysis.The result of study shows that: Among the several structures used in heat element, the palisade structure and the spiral structure have higher efficiency with lower current value. These two structures can be selected according to the actual situations that require different temperature. Although high-strength graphite heating material has a lower resistivity, the heat efficiency can be greatly improved by changing the structure and structural parameters. The result of simulation analysis on the heat efficiency of the palisade structure is coincide with the result which got in experiment. The theoretical and numerical simulation both showed that the temperature which is from the heating element to the soil around the heating element decreases with increase of the radial distance from the heating element and the temperature will be stable when the distance reaches a certain value. |
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