SELF-ELEVATING DRILLING OFFSHORE UNIT OF ICE CLASS WITH SINGLE CONIC PILE-SUPPORTED LEG AND ADJUSTING SEATS Russian patent published in 2015 - IPC E02B17/02 

FIELD: oil and gas industry.

SUBSTANCE: system comprises the following: drilling unit having a floating hull with relatively smooth deck in its upper part and ice-bending form in its lower part passing downwards and inwards around the hull perimeter where the ice-bending form passes from the area close to the deck level and downwards to the area close to the hull bottom; area of ice deflector passing around the hull, not under the hull; at least three legs installed inside perimeter of the flowing hull bottom, at that the legs are designed to be retracted from the sea bottom in order to tug the drilling unit through shallow water as well be retracted towards the sea bottom and be retracted partially for complete or partial removal of the hull from water; and self-elevating device connected to each leg both for elevation of the leg from the sea bottom so that the self-elevating drilling offshore unit of ice class could float due to hull buoyancy and for retraction of legs towards the sea bottom when there is no ice; and single conic piled leg having the hull with supporting part at the bottom and upper deck at the top, at that the supporting part is fixed to piles driven to the sea bottom when construction of single conic piled leg is installed for usage with tilted surface that contacts ice around the hull, passing from a wider lower area to the narrower upper area where the lower area is placed below sea surface and upper area is placed above the sea surface; it includes units with adjusting seats made to receive shoe at least at one leg, fixed and kept at the same place for drilling through single conic piled leg; at that the drilling unit is made to elevate the hull over water and to drill through single conic piled leg, running down to water in order to transit into position of ice protection, at that ice may contact the ice-bending form of the drilling unit when ice is thin and the form is to be removed when ice is thick.

EFFECT: protection against ice impact and interaction of the drilling unit with single conic leg.

17 cl, 8 dwg