METHOD OF OIL WELL OFFSHOT DRILLING Russian patent published in 2017 - IPC E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: method of the oil well offshot drilling includes the continuous cutting of the production string interval and the cylindrical shaped cement stone from above and the truncated cone from the bottom, the insulation of the expansion interval by installing the lightly drilled insert from the soft metal of cylindrical shape longer, than the length of the cutting interval, in the upper part of which there is the channel, pumping into the expansion interval of the hardening sealing compound, the lightly drilled insert drilling after its polymerization, installation of the temporary cement plug below the branching and the whipstock in the main hole, the offshot drilling through the hardened sealing compound, the offshot drilling from the main hole, opening of the main hole by drilling the whipstock and the temporary cement plug. The continuous cutting of the production string interval and the cement stone is carried out in the vertical part of the bore hole. The lightly drilled insert has the central channel, covered from the top with the easily destroyed membrane. Drilling of the lightly drilled insert is carried out with the milling cutter, the lower end of which is provided with the cylindrical guide with the diametrical dimension, that allows to move inside the central channel according to the class of the loose-running fit, and the upper part of the cutter is equipped with centralizers.

EFFECT: offshot drilling, while keeping the main one in the tightness conditions and eliminating of the behind-the-casing flows.

6 dwg