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A check valve is provided for use in the tubing string of a fluid producing well. The check valve is removably seated within the restricted diameter of a seating nipple in the tubing string. Resilient holddown means at the base of the valve are provided for this purpose. The check valve comprises a

A check valve is provided for use in the tubing string of a fluid producing well. The check valve is removably seated within the restricted diameter of a seating nipple in the tubing string. Resilient holddown means at the base of the valve are provided for this purpose. The check valve comprises a hollow generally tubular body having a pierceable valve element positioned therein, the valve opens and closes in response to fluid pressures bearing thereon. To equalize the pressures above and below the valve the pierceable valve element may be ruptured by a conventional wireline spear, allowing the fluid to drain slowly through the valve.

대표청구항 ▼

A check valve for controlling back flow in the tubing string of a fluid-producing well, said string having a submersible pump positioned at its lower end, said tubing string further incorporating a seating nipple above the submersible pump, said check valve comprising: a retrievable generally tubula

A check valve for controlling back flow in the tubing string of a fluid-producing well, said string having a submersible pump positioned at its lower end, said tubing string further incorporating a seating nipple above the submersible pump, said check valve comprising: a retrievable generally tubular body adapted to seat in the seating nipple and having a first longitudinal bore extending therethrough, said body forming an annular valve seat and a stop shoulder spaced above the valve seat, said valve seat and stop shoulder defining the ends of a chamber which is part of the bore; a generally tubular valve element having a second longitudinal bore and being disposed in the chamber, said valve member having a transversely extending wall which is pierceable by a wireline tool and which closes off the second bore against fluid flow therethrough, said valve element being operative to prevent fluid flow through the first bore when it seats on the valve seat, said valve element being operative to permit fluid flow through the first bore when the valve element is unseated, the cross-sectional area of the peirceable wall available to be pierced being substantially less than the cross-sectional area of the first bore, whereby, when the wall is pierced, only restricted flow is permitted therethrough so as to avoid damaging the submersible pump.