SYSTEM FOR FEEDING SUBMERSIBLE ELECTRIC MOTOR AND FOR HEATING WELL FLUID Russian patent published in 2009 - IPC E21B36/04 H01B7/18 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil extraction, particularly to design of system for feeding submersible electric motor (SEM) and simultaneously to heating well fluid; invention can be implemented at oil fields with mechanised withdrawal of oil from wells. The system consists of SEM, of a control station, of a matching power transformer and of a cable line connecting them. The cable line consists of at least two sections of an electric cable (EC), one of which is connected to above ground feeding blocks and to the control station, while another is connected to SEM; HSC is located between them, current conducting cores of which are electrically in series connected to current conducting cores of EC. A cable-extender with a cable box of input for connection with SEM 1 can be used as EC. Current conducting cores of HSC are made out of steel, while current conducting cores of EC are made out of copper. Resistance of each current conducting core of HSC and phase voltage of feeding of the whole system is specified from reduced mathematic expressions. Also under nominal mode active power of SEM and HSC are distributed equally, and exactly under this condition SEM has maximum efficiency when fed from the source of alternating current with fixed amplitude of voltage.

EFFECT: facilitating high reliability of system at withdrawing oil of various viscosities including high viscous oil with high contents of tarry matters due to reduced starting current magnitude and also due to self-regulation of strength of current flowing through SEM and through heating section of cable (HSC) owing to presence of negative feedback on current and to consideration of dependence of current strength from viscosity and temperature of pumped fluid.

4 cl, 1 dwg