DOWNHOLE DRILLING ASSEMBLY WITH HYDRAULIC COUPLING AND ITS APPLICATION METHOD Russian patent published in 2017 - IPC E21B4/02 E21B17/02 

FIELD: mining.

SUBSTANCE: group of inventions relates to directional drilling. Downhole drilling assembly includes a drill string equipped with an internal passage for a fluid medium, a hydraulic motor located inside the drill string and having a stator and a rotor made able to rotate relative to the stator as a response to the drilling mud supply through the internal passage for the fluid medium, a drive shaft functionally connected with the rotor and made with the possibility of rotation as a response to the rotor rotation, a drilling bit functionally connected with the drive shaft and made with the possibility of rotation as a response to the drive shaft rotation, and a hydraulic coupling located in the drill string and having the first clutch made with the possibility of rotation with the drill string and the second clutch made with the possibility of rotation with the drive shaft. In the first configuration the first clutch is disconnected from the second clutch so, that the drive shaft and the drill bit rotate relative to the drill string as a response to the rotor rotation. In the second configuration the first clutch interacts with the second clutch as a response to the hydraulic pressure created by rotation of the drill string so, that the drive shaft and the drill bit rotate with the drill string.

EFFECT: provided is the possibility to transfer sufficient torque to release the seized drilling bit.

20 cl, 13 dwg