METHOD FOR RECONSTRUCTION OF AN INACTIVE WELL Russian patent published in 2023 - IPC E21B7/08 

FIELD: oil industry.

SUBSTANCE: invention is related to construction of wells intended for oil production, and, in particular, to technologies for drilling and completing sidetracks from the main wellbore to enable oil production from several productive underground reservoir zones. A method for reconstructing a well is claimed, in which kickoff and drilling of the first sidetrack are performed; a liner with pipes of maximum diameter is lowered above the kickoff window, where the liner head, made in form of a branch pipe with a half-turn helical line and a keyway, is installed below the planned window of the second sidetrack; the position of the head of the liner relative to the apsidal plane is determined; the wedge with the orienting lug is lowered; the window of the second sidetrack is cut out and the second sidetrack is drilled; after lifting the drill string, the wedge with the orienting lug is removed; the liner assembly of the second track with longitudinally profiled pipes in the upper part, to the shoe of which a hollow wedge is attached to the shear screws, is lowered; by pumping a cement slurry with a separating plug, the profiled pipes are inflated to the size of the second sidetrack and the inner diameter of the production string; then the liner of the second sidetrack is disconnected from the drill string; and the passability of the first sidetrack is restored.

EFFECT: reconstruction of an inactive well with the possibility of joint and separate production from sidetracks and the exclusion of the penetration of bridging agent and filtrate into the lower wellbores.

4 cl, 3 dwg