CASING STRING VALVE Russian patent published in 2021 - IPC E21B33/14 E21B34/06 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, in particular to the cementing of casing strings. The casing valve includes a rigidly mounted sleeve and seat. The sleeve is installed in the lower part of the valve, equipped with an internal tapered groove in the lower part, flushing and central holes. The saddle is located above the sleeve, fixed with shear pins with the possibility of axial downward movement and is equipped with flushing holes and a central threaded hole. A locking sealing element is installed in the central hole, which is a metal cylinder with expanding plates fixed on it. On the outer side of the plates, a rubber sealing skirt is attached, which has the ability to open and tightly overlap the flushing holes of the sleeve when the saddle moves by cutting the pins after the displacement plug is seated in it.

EFFECT: invention is aimed at increasing efficiency of the valve for the casing by creating a reliable and tight shutoff of the lower part of the casing from the penetration of cement into the casing after the completion of cementing.

1 cl, 2 dwg