SLIDING COUPLING WITH DEFORMED BALL SEAT Russian patent published in 2017 - IPC E21B34/14 E21B43/26 

FIELD: technological processes.

SUBSTANCE: invention relates to tools for stepwise hydraulic fracturing of a formation. Sliding coupling is opened by a dropped ball. Coupling has a seat installed in a housing, and the seat has segments with deviation outwards from each other by a split ring or another deflecting element. First, the seat has an extended state in the sliding coupling, herewith the segments of the seat are expanded outside thrusted to the housing channel. When a ball of the proper diameter is dropped onto the borehole bottom, the ball is engaged with the extended seat. Supplied fluid medium pressure acting on the ball fitted into the seat moves the seat into the channel of the inner bushing. When this happens, the seat is reduced, which increases the square of the ball engagement with the seat. Finally, the seat reaches the collar in the inner bushing, herewith the supplied pressure acting on the ball fitted into the seat displaces the inner bushing in the housing to open a window for the sliding coupling passage.

EFFECT: technical result is higher efficiency of a sliding coupling with a deformed ball seat.

26 cl, 37 dwg