FIELD: oil and gas industry.
SUBSTANCE: inventions group relates to drilling multilateral oil and gas wells. The drilled window assembly contains the first pre-cut casing connection, containing the first tubular casing string element, having two or more grooves offset in the radial direction along its inner surface, located at an equal distance around the first tubular casing string element, the second pre-cut casing string connection, connected to the first pre-cut casing connection. The second precut joint comprises a second tubular casing member having a sidewall hole formed therein and an outer sleeve surrounding the sidewall hole in the second tubular casing member.
EFFECT: number of operations is reduced, time costs are reduced, access to lateral wellbores is simplified.
15 cl, 17 dwg
