Offshore structure comprising a stabilised processing column

Abstract

The invention relates to an offshore structure with a floating support carrying process equipment and a processing column supported thereon. The processing column is connected via a hinging connection such as to maintain its upright position under low frequency inclinations of the vertical centre line of the floating support. Hereby, efficiency of liquid and gas contacting in the column under sea going conditions is maintained.

1 . Offshore structure ( 1 ) comprising a floating support ( 4 ) carrying processing equipment ( 5 ) for hydrocarbons, a vertical column ( 6 ) with a vertical centre line ( 13 ) and an upper end and a lower end, the column having internal distribution members ( 8 ) for contacting liquid and gaseous products comprising hydrocarbons, and a fluid connection ( 7 ) between the processing equipment ( 5 ) and the column ( 6 ), wherein the column is mounted on the support ( 4 ) along its length or at one of its ends via a frame ( 10 ,  17 ) in a pivoting connection ( 12 ,  16 ) such that the vertical centre line can pivot around two perpendicular horizontal axes, in response to slow inclinations of the vertical axis of the floating support.  
     
     
         2 . Offshore structure ( 1 ) according to  claim 1 , comprising a displacement member ( 18 ,  19 ) which is connected to a control unit ( 20 ) that is adapted to actuate the displacement member ( 18 ,  19 ) for displacing the vertical centre line ( 13 ) of the column ( 6 ) by an amount corresponding to a slow inclination of a vertical axis ( 14 ) of the floating support ( 4 ) for maintaining the vertical centre line ( 13 ) at a constant position.  
     
     
         3 . Offshore structure ( 1 ) according to  claim 1 , the control unit ( 20 ) compensating variations in the inclination of the vertical axis ( 14 ) of the structure ( 4 ) with a period larger than 25 seconds, preferably larger than 0.5 hour.  
     
     
         4 . Offshore structure ( 1 ) according to  claim 1 , wherein the column ( 6 ) is with its upper end suspended from the frame ( 10 ) via the pivoting connection ( 12 ).  
     
     
         5 . Offshore structure ( 1 ) according to  claim 4 , the frame ( 10 ), having at least two legs, a displacement member being connected to at least one leg for lengthening or shortening the leg.  
     
     
         6 . Offshore structure ( 1 ) according to  claim 1 , wherein the column ( 6 ) is at its lower end supported by the frame ( 17 ), the displacement member ( 18 ,  19 ) being on one side connected to the offshore structure and on the other side to the column ( 6 ).  
     
     
         7 . Offshore structure ( 1 ) according to  claim 1 , wherein a damping member is connected to the column for damping movements with a period shorter than 0.5 hour, preferably shorter than 25 seconds.  
     
     
         8 . Offshore structure ( 1 ) according to  claim 7 , the damping member comprising a weight.  
     
     
         9 . Offshore structure ( 1 ) according to  claim 1 , the pivoting connection ( 12 ,  16 ) comprising a ball joint.  
     
     
         10 . Offshore structure ( 1 ) according to  claim 1 , the pivoting connection comprising a gimbal-table.  
     
     
         11 . Offshore structure ( 1 ) according to  claim 1 , the fluid connection ( 7 ) comprising a flexible line.  
     
     
         12 . Offshore structure ( 1 ) according to  claim 2 , the control unit ( 20 ) compensating variations in the inclination of the vertical axis ( 14 ) of the structure ( 4 ) with a period larger than 25 seconds, preferably larger than 0.5 hour.  
     
     
         13 . Offshore structure ( 1 ) according to  claim 2 , wherein the column ( 6 ) is with its upper end suspended from the frame ( 10 ) via the pivoting connection ( 12 ).  
     
     
         14 . Offshore structure ( 1 ) according to  claim 3 , wherein the column ( 6 ) is with its upper end suspended from the frame ( 10 ) via the pivoting connection ( 12 ).  
     
     
         15 . Offshore structure ( 1 ) according to  claim 2 , wherein the column ( 6 ) is at its lower end supported by the frame ( 17 ), the displacement member ( 18 ,  19 ) being on one side connected to the offshore structure and on the other side to the column ( 6 ).