DOWNHOLE HEATER Russian patent published in 2008 - IPC E21B36/00 

FIELD: induction heating devices, particularly to heat downhole liquids, particularly paraffinaceous oil and highly-viscous mixtures directly in wells.

SUBSTANCE: downhole heater is made as cylindrical tubular body oriented in well direction and provided with removable lids connected to tubular body ends. Upper lid of cylindrical tubular body has sealed current lead for electrical cable connection coupling and holder arranged on outer surface thereof. Holder end is flanged flow string coupling adapted to receive fastening bolts and provided with current lead orifices. Conical bush pressed with flow string coupling is arranged from cylindrical tubular body side. One section of flow string suspension means is coaxially arranged inside cylindrical tubular body and has outer surface provided with spaced apart induction cylindrical reels brought to connection cable along the tube. Cross-sectional tube dimensions in heater area may be aligned with flow string suspension tubes for oil transportation from well beyond the heater.

EFFECT: prevention of asphalt-tar-paraffin and hydrate deposit forming in flow strings of production wells developed by natural and artificial lift methods for a long time.

4 cl, 2 dwg, 1 ex