Underwell safety valve

• Main Author: RUOMING,LI CHEN
• Format: Patent
• Language: English
• Published: 25.07.2007
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The utility model relates to a downhole safety valve. Through the ground pressure, a push rod (5) pushes a nut (6), a fixed block (7), a stop ring (9) and a stop block (10) to move downward under the force of hydraulic pressure, and meanwhile a spring (8) and a compressing spring (11) are compressed. After a certain movement, the stop ring (9) matching the steps of an inner sliding sleeve (12) pushes the inner sliding sleeve to move downward simultaneously. When the inner sliding sleeve moves to the place of a valve flap (16), the valve flap is pushed aside and is in an open state, and a hold pressure state is kept. When the ground equipments of the oil-gas well break down and the pressure is leaked, the stop block can make the inner sliding sleeve reset which is under the force of the spring (8) and the compressing spring (11), and the valve flap resets under the force of a torsion spring (14) and is sealed with a valve body (13) for losing the support of the external machinery. The utility model has a liquid flow channel on the upper external tube, which are connected with each other by hydraulic pipelines, controlling the open and close of the valve flap, with the advantages of simple structure, high stability and low production cost.