System, lifting device and method for supporting a pipe string

Abstract

The invention relates to a system for supporting a pipe string ( 2 ) to which an additional pipe element has to be connected, comprising a lifting device ( 1 ), a wedge device ( 3 ) and an abutment element ( 4 ). The invention also relates to a lifting device ( 1 ) comprising an attachment foundation ( 10 ), a lifting arm ( 11 ), which is in linked connection with the attachment foundation ( 10 ) and a replaceable tension element ( 14 ) in the form of a circular are connected to the lifting arm, where the wedge device ( 3 ) is releasable secured to the tension element ( 14 ), thus enabling the wedge device ( 3 ) to be moved by means of the lifting device ( 1 ) from an inoperative position in a position above the abutment element ( 4 ) to an operative position where the wedge device ( 3 ) abuts against the abutment element ( 4 ), thus securing the pipe string ( 2 ) by means of the wedge effect. The invention also relates to a method.

1 . A system for supporting a pipe string ( 2 ) comprising at least one pipe element, to which pipe string ( 2 ) an additional pipe element has to be connected, where the pipe string may, for example, be a casing in a well, comprising a lifting device ( 1 ), a wedge device ( 3 ) and an abutment element ( 4 ), 
 characterised in that the lifting device ( 1 ) comprises an attachment foundation ( 10 ), a lifting arm ( 11 ) with an inner and an outer arm portion ( 12  and  13  respectively), which inner arm portion ( 12 ) is in linked connection with the attachment foundation ( 10 ) and a replaceable tension element ( 14 ) in the form of a circular arc connected to the outer arm portion ( 13 ), where the wedge device ( 3 ) is releasably secured to the tension element ( 14 ), thus enabling the wedge device ( 3 ) to be moved by means of the lifting device ( 1 ) from an inoperative position in a position above the abutment element ( 4 ) to an operative position where the wedge device ( 3 ) abuts against the abutment element ( 4 ), thus securing the pipe string ( 2 ) by means of the wedge effect.    
   
   
       2 . A system according to  claim 1 , 
 characterised in that the outer arm portion ( 13 ) is substantially U-shaped, with its open end facing away from the inner arm portion ( 12 ).    
   
   
       3 . A system according to  claim 1 , 
 characterised in that the wedge device ( 3 ) comprises a plurality of wedge elements ( 31 ) where the wedge elements ( 31 ) are connected individually to the tension element ( 14 ).    
   
   
       4 . A system according to  claim 1 , 
 characterised in that in an active position in abutment against the abutment element ( 4 ) the wedge device ( 3 ) completely encircles the pipe string ( 2 ).    
   
   
       5 . A system according to  claim 1 , 
 characterised in that the tension element ( 14 ) is releasably attached to the lifting arm ( 11 ).    
   
   
       6 . A system according to  claim 1 , 
 characterised in that the attachment foundation ( 10 ) comprises attachment devices for releasable attachment of the attachment foundation ( 10 ) to the abutment element ( 4 ) and/or a base.    
   
   
       7 . A system according to  claim 1 , 
 characterised in that the abutment element ( 4 ) is segmented.    
   
   
       8 . A lifting device ( 1 ) for lifting a wedge device ( 3 ) for the purpose of pipe connection of several pipe elements, 
 characterised in that the lifting device ( 1 ) comprises an attachment foundation ( 10 ), a lifting arm ( 11 ) and a replaceable tension element ( 14 ), where the lifting arm ( 11 ) has an inner arm portion ( 12 ) pivotally connected to the attachment foundation ( 10 ) and an outer arm portion ( 13 ), and that the tension element ( 4 ) is substantially in the form of a circular arc and is releasably, pivotally connected to the outer arm portion ( 13 ), thus enabling the wedge device ( 3 ) to be releasably attached to the tension element ( 14 ) for lifting out of and into an active position.    
   
   
       9 . A lifting device according to  claim 8 , 
 characterised in that the outer arm portion ( 13 ) of the lifting arm ( 11 ) is substantially U-shaped.    
   
   
       10 . A lifting device according to  claim 8 , 
 characterised in that the tension element ( 14 ) comprises a ring element in the form of a circular arc, where the open section of the circular arc is substantially equal to or slightly smaller than the pipe diameter of the pipe string ( 2 ) that has to be supported.    
   
   
       11 . A lifting device according to  claim 10 , 
 characterised in that the length of the tension element ( 14 ) is at least equal to or longer than the outer circumference of the pipe string ( 2 ) that has to be supported.    
   
   
       12 . A lifting device according to  claim 10 , 
 characterised in that stoppers ( 16 ) are attached on the tension element's ( 14 ) ends of the circular arc.    
   
   
       13 . A lifting device according to  claim 8 , 
 characterised in that a bracket ( 17 ) is attached to the lifting arm ( 11 ) near the bottom of the U-shape and that a central point of the tension element's ( 14 ) circular arc is pivotally connected to the bracket ( 17 ).    
   
   
       14 . A lifting device according to  claim 8 , 
 characterised in that the outer portions of the U-shaped arm portion ( 13 ) are connected to at least two points on the tension element ( 14 ) by at least two flexible connecting elements ( 18 ).    
   
   
       15 . A lifting device according to  claim 12 , 
 characterised in that there are two connecting elements ( 18 ) and that these are mounted at opposite sides of the tension element ( 14 ).    
   
   
       16 . A lifting device according to  claim 12  or  13 , 
 characterised in that the attachment points for the connecting elements ( 18 ) on the lifting arm ( 11 ) are spaced at a greater distance apart than the attachment points for the connecting elements ( 18 ) on the tension element ( 14 ).    
   
   
       17 . A method for releasably supporting a pipe string during connection of a new pipe element to the pipe string, 
 characterised in that for a lifting device a tension element is chosen which is adapted to the diameter of the pipe element of the pipe string that has to be supported, that a wedge device is mounted on the tension element, that an abutment element is placed round the pipe element, that the lifting device with the wedge device are secured relative to the abutment element, that the wedge device is lowered to an active position by the lifting device, thus securing the pipe string.    
   
   
       18 . A method according to  claim 15 , 
 characterised in that the wedge device comprises wedge elements which are inserted onto the tension element.