FIELD: mining.
SUBSTANCE: group of inventions relates to a deflector assembly of a multilateral borehole, a method for forming a multilateral borehole, and to a multilateral borehole. Deflector assembly of a multilateral borehole comprises a tubular element, part of a polished receiving socket, an outlet window, and an inclined deflector. The tubular element is comprised of a tubular part of the lateral wellbore located higher in the wellbore and a tubular part of the main wellbore located lower in the wellbore. The inner diameter (IDU) of the tubular part of the lateral wellbore located higher in the wellbore is larger than the inner diameter (IDD) of the tubular part of the main wellbore located lower in the wellbore. The part of the polished receiving socket is located between the tubular part of the lateral wellbore and the tubular part of the main wellbore located lower in the wellbore. The polished receiving socket is made configured to tightly seal the downhole tool passing through the inner diameter (IDU) of the tubular part of the lateral wellbore located higher in the wellbore, and in the direction towards the tubular part of the main wellbore. The outlet window is located in the side wall of the tubular part of the lateral wellbore located higher in the wellbore. The inclined deflector is located inside the tubular part of the lateral wellbore located higher on the wellbore in the immediate vicinity of the outlet window, inclined towards said window. The inclined deflector additionally comprises a through channel with a diameter (DTB), connecting the tubular part of the lateral wellbore located higher in the wellbore and the tubular part of the main wellbore located lower in the wellbore. The through channel forms the edge of the inclined deflector in order to ensure the passage of the first downhole tool, with a diameter (D1) less than the diameter (DTB), through the inclined deflector towards the tubular part of the main wellbore located lower in the wellbore and to divert the second downhole tool, with a diameter (D2) larger than the diameter (DTB), towards the outlet window.
EFFECT: provided suitable surface for sealing with a downhole tool deployed inside the deflector assembly.
14 cl, 16 dwg
