METHOD FOR CONSTRUCTION OF MULTI-BARREL WELL AND GUIDE DEVICE FOR INSTALLATION OF CASING STRING IN ITS ADDITIONAL SHAFT Russian patent published in 2019 - IPC E21B7/08 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to oil and gas industry and can be used for drilling and fastening additional wellbores of multi-barrel well from previously drilled cased wells. Method of multi-barrel well construction includes opening of window in casing of primary borehole and drilling of the new additional borehole to the design depth using the extracted wedge-deflector, lowering the shank with casing pipes to the mouth of the new additional borehole with further sealing of the additional borehole, treatment of upper part of shank to obtain access to lower part of primary shaft, extraction of wedge-deflector, wherein inner diameter of casing of primary shaft before lowering wedge-deflector in area of window and above is expanded, wedge-diverter with anchor is removed until shank is lowered, which is made in the form of longitudinal corrugated pipe with increased perimeter in expansion zone of inner diameter of casing of the primary shaft. Shank lowered on the pipe string is placed in the additional shaft by means of a guide shoe attached from below. Corrugated sections of liner are straightened with excess pressure with fixation by rolling in additional barrel. Upper part of the shank is processed in two stages, at the first of which the guide window is cut in the shank to create communication with the primary shaft, on the second one – expansion of the upper part of the shank till it is pressed to expansion flush to the walls of the primary shaft. Guide shoe is inserted into the lower part of the shank with possibility of tight longitudinal movement. Shank before the lowering is equipped from the inside with the possibility of joint rotation by the hollow process string communicated by the side channels with the tight cavity of the shank and connected from below to the guide shoe, and from above – from the pipe string. Below lateral channels in the process string a saddle is placed under a drop-off element from the wellhead, after discharge of which into the well, the corrugated sections of the shank are redressed with excessive pressure with subsequent disconnection and removal of the guide shoe onto the surface.

EFFECT: higher reliability of the method and device, increased efficiency of the well and simplified process of isolation of the zones of complications, reduced accident rate and construction time of multi-barrel wells.

2 cl, 4 dwg