DEVICE FOR STRING DISCONNECTION Russian patent published in 2012 - IPC E21B23/06 E21B17/06 

FIELD: oil and gas industry.

SUBSTANCE: device for string disconnection consists of housing connected to adapter from above and sleeve from below. There are through radial holes in the housing that are covered by adapter. There is a perforated bush installed in the upper part of the device between housing and rod in the through radial holes of which there inserted are shear elements fixing movable hollow piston in initial position, note that the upper end of perforated bush is a thrust for fixing element. The rod has a groove for interaction with fixing element. Chevron seal between housing and rod connected in movable manner is limited by shock absorbing bush from above and sleeve from below. The adapter is rigidly connected to the rod lower end, the sleeve is rigidly connected to the housing, the sleeve and adapter have slots that form slotted joint. Device disconnection can be done via tubing pressure supply with ball discharge or without it as well as casing pressure supply due to combination of seals between movable hollow piston, adapter, rod and housing.

EFFECT: increase of device disconnection and connection reliability.

4 cl, 1 dwg