FIELD: oil recovery. SUBSTANCE: electric pump is provided with drain and check valves fitted on oil well tubing, sections with inlet module or gas separator and submersible electric motor with hydraulic protection which are connected in series. Fitted between upper section of pump and drain valve is sludge branch pipe which is blanked off at the top and provided with through radial holes below blank. EFFECT: avoidance of choking of check valve and upper stages of pump. 2 dwg
