JACK-UP DRILLING RIG WITH TWO DERRICKS FOR OPERATION UNDER ICE CONDITIONS Russian patent published in 2015 - IPC E02B17/02 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to the jack-up drilling rigs and to drilling methods at shallow waters with possible ice presence. The jack-up drilling rig contains floating hull with top deck; part of the floating hull for ice bending projecting downward from the deck perimeter and tapering inside; edge reflecting ice projecting vertically downward from bottom perimeter of the above mentioned part for ice bending to direct ice around the above mentioned floating hull, not under it; supports arranged inside the perimeter of the above mentioned floating hull; jack-up device connected with each support; two derricks installed on the deck. Two specified derricks are located from one horizontal side of the specified deck relatively to the first central line of the deck and at opposite horizontal sides of the specified deck relatively to second central line of the deck perpendicular to the first central line of the deck, or at opposite sides of the specified deck at similar distance from the deck centre, at that the specified first central line is parallel to the longitudinal axis of the specified derricks. Drilling method at shallow waters with possible ice presence includes: a) provision of the specified jack-up drilling rig; b) lowering of each support to sea bed and hull lifting from water, if ice is not dangerous for the rig; c) floating hull lowering on water with anti-ice configuration such that shape for ice bending projects above and below sea surface for break or removal of ice approaching the rig, if ice is dangerous for the rig; d) drilling using both derricks during steps b) and/or c).

EFFECT: technical result is increased efficiency of exploration and extension of the drilling season at places with possible ice presence.

14 cl, 8 dwg