Derrick apparatus

Abstract

A derrick apparatus for a drilling machine ( 10 ), the apparatus comprising a fixed structure ( 48, 50 ) for supporting drill equipment ( 14, 16 ), wherein the fixed structure ( 48, 50 ) has a generally prismatic shape with a generally constant cross-section along the vertical extent of the fixed structure ( 48, 50 ), and wherein the fixed structure ( 48, 50 ) comprises supporting beams ( 48, 50 ) about outer parts of the fixed structure and a void extending across the internal width of the fixed structure ( 48, 50 ).

1 . A derrick apparatus for a drilling machine, the apparatus comprising a fixed structure for supporting drill equipment, wherein the fixed structure has a generally prismatic shape with a generally constant cross-section along the vertical extent of the fixed structure, and wherein the fixed structure comprises supporting beams about outer parts of the fixed structure and a void extending across the internal width of the fixed structure. 
     
     
         2 . A derrick apparatus as claimed in  claim 1  wherein at least one beam is hollow and generally vertically oriented, and wherein the vertical beam is used as a conduit for one or more of cabling, pipe work, access way and/or a personnel elevator. 
     
     
         3 . A derrick apparatus as claimed in  claim 1 , wherein the fixed structure comprises an integrated drill floor. 
     
     
         4 . A derrick apparatus as claimed in  claim 1 , wherein the derrick apparatus is a unitary structure comprising the fixed structure in combination with the integrated drill floor, whereby the derrick apparatus including the drill floor can be installed as a single unit. 
     
     
         5 . A derrick apparatus as claimed in  claim 1  wherein supporting beams of the fixed structure extend vertically through an integrated drill floor such that both the fixed structure and the drill floor are supported by the beams, and the beams extend beneath the drill floor toward a base of the derrick apparatus. 
     
     
         6 . A derrick apparatus as claimed in  claim 5 , wherein the supporting beams are for connecting to a foundation structure to thereby mount the unitary derrick and drill floor apparatus on the foundation structure. 
     
     
         7 . A derrick apparatus as claimed in  claim 1 , wherein the derrick apparatus is a derrick for a drillship and the fixed structure is arranged for a direct connection to the structure of the ship. 
     
     
         8 . A derrick apparatus as claimed in  claim 1 , comprising a main drill line and one or more additional firing line(s). 
     
     
         9 . A derrick apparatus as claimed in  claim 8 , wherein the main drill line comprises a fastline running between the crown block and a drawworks and/or a dead line running between the crown block and dead line anchor passes and wherein the fastline and/or dead line is outboard of the prismatic shape of the fixed structure. 
     
     
         10 . A derrick apparatus as claimed in  claim 8 , wherein the additional firing line(s) are formed by or supported by structures extending away from the fixed structure so that the firing line(s) is/are outboard of prismatic shape of the fixed structure. 
     
     
         11 . A derrick apparatus as claimed in  claim 1  comprising a folding top structure supported on the fixed structure and having an erected position and a folded position, wherein when in the erected position the top structure is for supporting a top drive drilling machine and wherein at least a part of the top structure is arranged to fold around and/or beside a part of the fixed drill equipment on the fixed structure such that when the top structure is in the folded position the height of the derrick may be reduced to the height of the fixed drill equipment without disturbing the fixed drill equipment. 
     
     
         12 . (canceled) 
     
     
         13 . A derrick apparatus as claimed in  claim 11 , wherein the folding structure comprises an arrangement of two or more hinged beams, for example box beams or girders, and wherein there is a void between two beams. 
     
     
         14 . A derrick apparatus as claimed in  claim 11 , wherein a void or multiple voids are used to provide space for parts of the folding structure, to enable the folding structure to move close to the fixed structure and/or to permit parts of the folding structure to be placed around or beside the fixed drill equipment. 
     
     
         15 . (canceled) 
     
     
         16 . A derrick apparatus as claimed in  claim 11 , wherein a part or part(s) of the folding structure are movably connected to the fixed structure at the height of the highest part of the fixed drill equipment or below that height and wherein the movable connection comprises a joint arranged for a sliding connection of the part of the folding structure relative to the fixed structure. 
     
     
         17 - 18 . (canceled) 
     
     
         19 . A derrick apparatus as claimed in  claim 11 , wherein the folding top structure comprises a first part with a rotating connection to the fixed structure and a second part with a rotating connection to the first part and wherein, the second part is rotatably connected to the first part at a point spaced from the rotating connection of the first part to the fixed structure, and wherein the second part is releasably connected to the fixed structure at a point spaced from the rotating connection of the second part to the first part. 
     
     
         20 . (canceled) 
     
     
         21 . A derrick apparatus as claimed in  claim 16 , wherein the connection of the first part and the second part is at an upper location on the top structure when it is in the erected position and forms a mounting point for the crown block and/or for the top drive drill machine. 
     
     
         22 . A derrick apparatus as claimed in  claim 19 , wherein the folding structure is arranged such that when folded, the first part folds down around or beside a part of the fixed drill equipment and the second part is slid down beside the fixed structure. 
     
     
         23 . (canceled) 
     
     
         24 . A derrick apparatus as claimed in  claim 11 , wherein the folding top structure comprises a frame rotatably connected at a first point to a first side of the fixed structure with an inclined beam rotatably connected to the frame at a second point spaced away from the first point and the inclined beam releasably connected to the fixed structure at a third point spaced away from the second point and the first point. 
     
     
         25 . A derrick apparatus as claimed in  claim 24 , wherein the frame is an A-frame and preferably includes a void enabling it to fold over and about a part of the fixed drill equipment on the fixed structure. 
     
     
         26 . A derrick apparatus as claimed in  claim 24 , wherein the inclined beam slides down a side of the fixed structure when the folding structure is moved to its folded position. 
     
     
         27 . A derrick apparatus as claimed in  claim 11 , wherein the folding top structure provides an offset drill centre and is arranged such that the mounting point for the crown block and/or drill line is offset from the centre of the fixed structure. 
     
     
         28 . A derrick apparatus as claimed in of  claim 11 , wherein the folding top structure supports the weight of the top drive and drill string when in operation and/or wherein when in the erected position the top structure used to support the crown block and the top structure is arranged such that in the folding operation the crown block remains connected to the top structure and moves with it to the folded position. 
     
     
         29 - 40 . (canceled) 
     
     
         41 . A method of manufacture of a derrick apparatus for a drilling machine, the method comprising: providing a fixed structure for supporting drill equipment, wherein the fixed structure has a generally prismatic shape with a generally constant cross-section along the vertical extent of the fixed structure, and wherein the fixed structure comprises supporting beams about outer parts of the fixed structure and a void extending across the internal width of the fixed structure. 
     
     
         42 . A method as claimed in  claim 41  comprising providing a unitary structure with a drill floor integrated with the fixed structure. 
     
     
         43 . A method as claimed in  claim 42  comprising manufacture of the unitary structure at an onshore site followed by installation of the unitary structure onto a vessel such as a drill ship. 
     
     
         44 - 46 . (canceled)