METHOD OF FORMING A JOINT OF MULTILATERAL WELLS Russian patent published in 2024 - IPC E21B7/08 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to construction of multilateral wells and overhaul of oil and gas wells. Method of formation of butt joint of multilateral wells involves drilling of a side hole through a "window" from a previously cased and cemented main borehole of the well and lowering of a liner to the side hole. At the same time the upper part of the liner is placed in the open shaft directly below the "window" and a mechanical connection device is installed in the interval of the "window". Mechanical connection device consists of a body, an anchor unit and a connection unit. In the housing there are holes for fluid supply from the main shaft. There is a left-hand thread on the inner surface of the connection assembly, by means of which the device is connected to the lowering tool and the device is activated in the well. There is a groove on the inner surface of the connection assembly above the left-hand thread, by means of which the device is connected to the tool for deactivation and removal of the device from the well. Lower part of the mechanical coupling device is coupled with the upper part of the shank in the open side shaft, and its upper part is installed in the main shaft.

EFFECT: higher efficiency of sidetracking and field development.

1 cl, 6 dwg