FIELD: oil and gas industry.
SUBSTANCE: method includes lowering into well, to depth of forming of deposits, of linear heating element in form of pipes column in well or of metallic conductor and feeding conductor. Heating is performed by letting high-frequency electric current through feeding conductor while providing for its locking in head portion of heating system at depth of forming of deposits. Metal of linear heating element is effected with high-frequency field of feeding conductor. Frequency of electric current is set at lower limit on basis of condition, that depth of penetration of high-frequency field into metal of linear heating element was less than its thickness. Heat production is adjusted to provide primary heat production along linear heating element by decreasing space between the latter and feeding conductor and by increasing frequency of electric current from this lower limit. Locking of electric current in head portion of heating system between heating element and feeding conductor is performed through locking element, having falling dependence of resistance from temperature increase. Frequency of electric current is set at lower limit during lowering of heating system and is increased after passing whole depth of forming of deposits and obstructions. Locking of electric current in head portion of heating system can be performed through substance, having properties of weak electrolyte, for example, through well liquid, and frequency of electric current is increased in area of manifestation of effect of steep increase in its productiveness. Device has heating system, consisting of feeding conductor and linear heating element, and locker of electric current between these in its head portion. Feeding conductor is made of coiled and isolated conductors. Linear heating element is in form of column of pipes in the well or a bare metallic conductor. Cross-section of conductor is selected to be enough for supporting weight of heating system lowered into well. Electric current locker in head portion of heating system is made in form of winding of high-frequency wire, woven on ferrite core and placed inside metallic cover in such a way, that ferrite core by end portions is locked on this cover. Grade of ferrite of core is selected from condition, that its temperature of magnetic properties loss should exceed temperature of melting of deposits in a well, but is not greater than temperature of their combustion or carbonization. Current locker in head portion of heating system may be made in form of bare electrode, connected to feeding conductor and placed relatively to heating element in such a way, that between them a channel is formed along axis of bare electrode for passing of well liquid.
EFFECT: higher efficiency, higher reliability.
2 cl, 4 dwg
Authors
Dates
2005-03-20—Published
2003-09-10—Filed