BOTTOM-HOLE HEATER AND METHOD FOR IMPROVEMENT OF OIL RECOVERY USING IT Russian patent published in 2015 - IPC E21B36/04 E21B43/24 

FIELD: oil and gas industry.

SUBSTANCE: heating method of a hydrocarbon-bearing formation by a bottom-hole heater consists in installation of the bottom-hole heater and supply to it of current so that the bottom-hole heater provides heating performed by electric resistance of at least one section of the formation. Heat power of the bottom-hole heater is changed depending on the state of its surrounding medium. The bottom-hole heater includes a cylindrical or tubular housing with heating elements and a current lead in the upper part. The heater has an additionally installed hydroprotection device representing an elastic membrane filled with a liquid heat carrier. With that, the upper part of the elastic membrane is fixed by means of a clamp on an intermediate bush attached to the housing, and the lower part is attached with a clamp by means of a bush to a pipe. Heat carrier is contained in the space restricted by the head, the pipe, the housing, the intermediate bush and the elastic membrane. Additionally, well liquid flowing through the heater is heated by the heater.

EFFECT: increasing operating life of a bottom-hole heater, improving its reliability and increasing operating safety of the well.

4 cl, 4 dwg, 4 tbl