DOWN-HOLE INDUCTION HEATER Russian patent published in 2003 - IPC

FIELD: oil production industry, electric heaters employed in process of extraction of viscous oil from wells. SUBSTANCE: down-hole induction heater includes enclosure, bearing member carrying induction coils. Bearing member comes in the form of rod placed uniaxially in enclosure and joined to it in upper and lower parts with the aid of attachment units produced from non-magnetic material. Induction coils are additionally fitted with ferrite magnetic circuits with pole pieces facing walls of enclosure and uniformly spaced over length of rod by distance multiple of length of induction coil. Intercoil spaces are filled with non-magnetic and non-conductive material. Rod and enclosure are also made of nonmagnetic and non-conductive material. Pole pieces of magnetic circuits, non- magnetic and non-conductive material of intercoil spaces include conduits for series connection of induction coils. Induction heater is supplemented with temperature-sensitive element built into upper attachment unit. Employment of induction heater makes it feasible to raise efficiency of fluid heating in well and in space of productive pool, to expand functional capabilities and to simplify operation of heater thanks to reduction of its own magnetic and electric losses and its manufacture in the form of geophysical instrument. EFFECT: raised efficiency of fluid heating in well and in space of productive pool. 1 dwg