MULTILATERAL WELL CONSTRUCTION METHOD Russian patent published in 2024 - IPC E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely to construction of multilateral wells. Method of construction of multilateral well includes drilling of main shaft to design corridor of drilling of additional shaft, on which straight section is made with length sufficient for sidetracking window on it. Drilling of the main shaft is continued until it reaches the design zenith angle, thus the main shaft acquires a trajectory having the design zenith angle and providing a place for sidetracking of the additional shaft and its drilling within the productive deposits. Then the production string is lowered and cemented in the main shaft. In the production string at the end of drilling of the main shaft, below the planned interval of cutting the window, a rubberized longitudinally shaped pipe with a drillable plug is installed, branch pipe with helical half-turn surface, ending with key slot for oriented installation of starting wedge. After that, a window is cut out on the straight section, a separating packer is installed below the window, an additional shaft is drilled, then the flotation of the main shaft is restored.

EFFECT: simplified construction of multilateral well.

1 cl, 4 dwg