WELL DRILLING METHOD Russian patent published in 2008 - IPC E21B7/00 H01B7/282 

FIELD: well drilling, particularly methods to drill orifices from predetermined area in existent well passing through underground reservoir carrying hydrocarbon fluid, and micro-drilling device.

SUBSTANCE: method involves moving drilling device provided with remote control and electric drive from ground surface along hydrocarbon fluid production pipe to selected area in existent well bore, wherein the pipe is sealed with respect to casing pipe wall; bringing drilling device in action so that cutting surfaces thereof may drill orifice from selected area of existent well to create drilling cuttings, wherein as drilling device operates the first produced fluid flow passes to ground surface through hydrocarbon fluid production pipe and the second produced fluid flow is injected over cutting surfaces of drilling device by means of downhole injection device provided with remote control and electric drive; conveying drilling cuttings entrained by the second produced fluid flow from drilling device. Assembly for said method realization comprises body having fluid channels, gripping device to be expanded in radial direction and having electric or hydraulic drive, as well as injection device having electric drive. Electric motor is adapted to activate drilling bit mounted on pushing device provided with electric or hydraulic drive. The drilling bit has cutting surfaces sized to create drilled orifice with diameter of 0.2-3 inches.

EFFECT: possibility to produce hydrocarbon fluid from existent well during orifice drilling from selected area.

35 cl, 5 dwg