DRILLING METHOD OF ADDITIONAL BORE FROM PRODUCTION STRING OF WELL Russian patent published in 2009 - IPC E21B7/06 

FIELD: mining engineering.

SUBSTANCE: invention relates to construction of multihole wells, particularly to drilling technique of additional bore from production string. It includes predrilling of additional bore of minor diametre as compared with major, with usage of whipstock, up to top of producing formation, its fixation by expanding shaped tube with pumping in of insulating material, and producing formation exposing with keeping on bottomhole of pressure, equilibrium to intrastratal or depressive relative to it. Additionally pumping-in of insulating material is implemented after lowering of shaped tubes, which are in suspension and allowing channels in bottom part, through which it is implemented filling of additional bore by insulating material bottom-up, after what shaped tubes are lowered with supporting on bottomhole, and channels overlapping with following expanding of shaped tubes and expansion of its top part.

EFFECT: it up-grades construction of additional bore ensured by reduction of time domain between pumping-in of insulating material into disclosed part of bore and its fixation by shaped tubes, and also there are reduced material costs for construction of additional bore from flow string of well ensured by reduction of round-trips.

2 dwg