RELEASING SPEAR Russian patent published in 2012 - IPC E21B31/18 

FIELD: oil and gas industry.

SUBSTANCE: device contains: telescopical housing which inner and outer parts are spring-loaded in opposite directions and fixed in transport position with limit stop, collet installed in inner part of the housing with possibility of movement restricted from above by inner part and from below - by cone narrowing of housing outer part. Inner part is provided with limit stop, and outer part is provided with groove for limit stop. Outer part opposite to chamber formed by inner and outer parts in transport position is provided with holes interconnected with space outside the housing. In upper end of collar there are overflow channels made, in lower end of inner part of housing there are lower channels connected to overflow channels of collar. In inner part there are upper channels made interconnected with space outside the housing, and there are process holes arranged between upper and lower channels. Limit stop is made in the form of balls inserted into process holes and pressed from inside by hollow sleeve. The sleeve shuts off upper channels of this part, it is designed with possibility of interacting with waste ball from wellhead and of hollow sleeve downward movement accompanied by upper channels being opened. Collar is connected to inner part of the housing with possibility of restricted movement.

EFFECT: increasing reliability of the design, reducing primecost.

1 dwg