System and Method for Installing Foundation Elements

Abstract

The invention pertains to a system ( 1 ) for installing foundation elements, such as piles or conductors ( 2 ), in a sub-sea ground formation ( 3 ), comprising a hydraulic driver ( 8 ) and a power converter ( 9 ) for generating hydraulic pressure in a hydraulic fluid for the driver ( 8 ). The driver ( 8 ) and the converter ( 9 ) are adapted to fit inside the foundation elements ( 2 ).

1 . System ( 1 ) for installing foundation elements, such as piles or conductors ( 2 ), in a sub-sea ground formation ( 3 ), comprising a hydraulic driver ( 8 ) and a power converter ( 9 ) for generating hydraulic pressure in a hydraulic fluid for the driver ( 8 ), characterised in that the driver ( 8 ) and the converter ( 9 ) are adapted to fit inside the foundation elements ( 2 ). 
   
   
       2 . System ( 1 ) according to  claim 1 , comprising a tank ( 10 ) for a hydraulic fluid, which tank ( 10 ) is mounted on or integrated with the converter ( 9 ). 
   
   
       3 . System ( 1 ) according to  claim 1  or  2 , comprising a hydraulic cylinder ( 11 ), a piston ( 12 ) accommodated in the hydraulic cylinder ( 11 ), high and low-pressure accumulators ( 13 ,  14 ), and a valve system ( 15 ) for alternately connecting the hydraulic cylinder ( 11 ) to the high and low-pressure accumulators ( 13 ,  14 ), wherein the cylinder ( 11 ), piston ( 12 ), accumulators ( 13 ,  14 ), and valve system ( 15 ) are mounted on or integrated with the converter ( 9 ;  26 ). 
   
   
       4 . System ( 1 ) according to any one of the preceding claims, comprising an impact weight ( 17 ) adapted to reciprocate inside a foundation element ( 2 ) and preferably to abut the inner wall of the foundation element ( 2 ), which impact weight ( 17 ) is connected to the piston ( 11 ) by means of a flexible element ( 19 ). 
   
   
       5 . System ( 1 ) according to any one of the preceding claims, comprising an acceleration compartment located above the piston ( 11 ) and/or communicating with a chamber ( 16 ) above the piston ( 11 ). 
   
   
       6 . System ( 1 ) according to any one of the preceding claims, wherein the driver ( 8 ) and/or the converter ( 9 ;  26 ) comprises a means for securing the driver ( 8 ) and/or the converter ( 9 ;  16 ) and any components integrated therewith to the inner wall of the foundation element ( 2 ). 
   
   
       7 . System ( 1 ) according to any one of the preceding claims, wherein the converter ( 9 ;  26 ), preferably a fluid pressure converter, comprises a fluid inlet adapted to be connected to a drill string ( 5 ), such that a fluid can be fed through the drill string ( 5 ) to the converter ( 9 ;  26 ). 
   
   
       8 . Method of installing hollow foundation elements, such as piles or conductors ( 2 ), in a sub-sea ground formation ( 3 ), by means of a hydraulic driver ( 8 ) and a power converter ( 9 ) for generating hydraulic pressure in a hydraulic fluid for the driver ( 8 ), which method comprises the steps of
 mounting the driver ( 8 ) and the converter ( 9 ;  26 ) inside the foundation element ( 2 ),   lowering the foundation element ( 2 ), the driver ( 8 ), and the power converter ( 9 ) from a vessel ( 4 ).   
   
   
       9 . Method according to  claim 8 , wherein the converter ( 9 ;  26 ) and any components integrated therewith is lowered by means of a drill string ( 5 ). 
   
   
       10 . Method according to  claim 9 , wherein an energy transferring fluid is fed to the converter ( 9 ;  26 ) through the drill string ( 5 ). 
   
   
       11 . Method according to any one of  claims 8 - 10 , wherein the driver ( 8 ) and the power converter ( 9 ) are positioned and preferably secured inside the foundation element ( 2 ) before lowering the foundation element ( 2 ), the driver ( 8 ), and the power converter ( 9 ) to the formation ( 3 ). 
   
   
       12 . Method according to any one of  claims 8 - 11 , wherein the converter ( 9 ;  26 ) and elements integrated therewith are secured to the inner wall of the foundation element ( 2 ). 
   
   
       13 . Method according to any one of  claims 8 - 12 , wherein water below the converter ( 9 ;  26 ) is replaced by a gas, thus reducing the resistance on the impact weight ( 17 ) during reciprocating movement inside the foundation element ( 2 ). 
   
   
       14 . Method according to any one of  claims 8 - 13 , wherein the impact weight ( 17 ), during reciprocating movement, is guided by the inner wall of the foundation element ( 2 ).