INDUCTION WELL HEATING DEVICE Russian patent published in 2017 - IPC E21B36/04 E21B43/24 

FIELD: oil and gas industry.

SUBSTANCE: induction well heating device includes a housing, a hollow ferromagnetic core coaxially disposed therein, and induction coils, the winding wires of which are in series connected to each other, and a transition clutch mounted on one side of the housing. The clutch is made with the possibility to connect the heating device to the tubing string and is equipped with a current lead for connecting the supply cable to the windings of the induction coils. Wherein the core is arranged in the housing with forming an annular cavity made communicating with the core cavity by means of through openings in the core wall at its end portions. Wherein the housing is made ferromagnetic. Successive induction coils and annular ferromagnetic teeth are mounted in the annular cavity of the housing. Moreover, said annular teeth are made with equally deep slots along the perimeter, through which insulated wires are laid to connect the induction coils into phase windings, and also the spokes-inserts fixing the annular teeth from the axial movement. Wherein the coils of the windings of each phase are made two-row and are distributed along the length of each pole division alternately with the teeth at the equal ratio of their quantities. Wherein the housing butts are sealed with a plug made on one side of the housing, provided with a bypass valve connected to the annular cavity and, on the other side, with a transition clutch additionally equipped with a check valve, the passageway of which is connected to the core cavity.

EFFECT: increasing the reliability and efficiency of the heating device by optimizing the magnetic circuit, increasing the induction component of power and preventing the overheating of induction coils, improving the heat transfer, ensuring reliable sealing and protection in the well at high pressures.

6 cl, 3 tbl, 2 dwg