SAFETY VALVE FOR A SUBMERSIBLE ELECTRIC CENTRIFUGAL PUMP UNIT

The invention relates to the oil industry and can be used for oil production. A safety valve is intended for mounting in a landing nipple in a wellbore and comprises a composite housing having a central passage, a shutoff element and a control mechanism. The shutoff element comprises a collet and a movable mandrel having stops located in the upper part. When the shutoff element moves axially, the stops extend through the composite housing through grooves and thus interact with a stop surface of the landing nipple. The control mechanism comprises a spring-loaded tubular plunger having a ring piston on its upper outer surface and longitudinal openings in its lower part, the openings being configured to align with similar openings in the composite housing to allow functioning of the safety valve. The movable mandrel is connected to the head of the safety valve at the mandrel top and rests against the plunger at the mandrel bottom. The movable mandrel has a series of grooves and shoulders on its outer surface, which, due to the use of the collet and lock balls, allow for taking one of the fixed positions. The technical effect is providing the uninterrupted reliable operation of the electrical submersible pump.