DEVICE FOR ATTACHING WELL WITH CASING LINER Russian patent published in 2009 - IPC E21B7/20 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to construction and operation of oil and gas wells providing for their being attached with casing liners with the possibility of pre-drilling additional shafts out of those wells, including shafts being positioned. The device includes a casing liner with a non-return valve located in its lower part, a wedge for pre-drilling an additional well shaft, a transportation column for lowering the casing liner and the wedge down to the well, and the point of attaching the casing liner and the wedge to the transportation column. That point is made with the possibility of anchoring the wedge in the well shaft when the device is in the working position, detaching the wedge from the transportation column in order to remove it from the well shaft, and attaching the wedge to the upper part of the casing liner. At that, the above attachment point is of hydraulic action with the possibility of implementing the above functions against various pressure values in the transportation column channel with the algorithm of its subsequent increase by 10-30% from function to function.

EFFECT: device for attaching the well with the casing liner.

5 cl, 3 dwg