Non-rotating linear actuator with hydraulic feed through

Abstract

Providing hydraulic fluid from a hydraulic pump to a tool connected to respective first and second ends of a wellbore linear actuator and such an actuator. The actuator has a double acting cylinder with a cylinder head, a cylinder cap opposite the cylinder head, a piston head, and a piston rod. The piston head separates the cylinder into a first chamber and a second chamber, and the piston rod extends out of the second chamber through the cylinder cap. The double acting cylinder has first and second ends, and the double acting cylinder further includes a feed fluid passage between the first and second ends, wherein the feed fluid passage includes a first fluid line through the piston head and the piston rod, the first chamber, and a second fluid line through the cylinder head. The double acting cylinder is configured for preventing said piston rod from rotating relative said cylinder bore.

1 . A non-rotating wellbore linear actuator comprising;
 a double acting cylinder with a cylinder bore, wherein the double acting cylinder comprises:
 a cylinder head; 
 a cylinder cap opposite said cylinder head; 
 a piston head; and 
 a piston rod, 
   wherein said piston head separates said cylinder bore into a first chamber and a second chamber, and said piston rod extends out of said second chamber through said cylinder cap,   wherein said double acting cylinder has a first end at the cylinder head and a second end at the external end of the piston rod, wherein said double acting cylinder further comprises a feed fluid passage between said first and second ends,   wherein said feed fluid passage comprises:
 a first fluid line through said piston head and said piston rod; 
 said first chamber; and 
 a second fluid line through said cylinder head, and 
   wherein said double acting cylinder is configured for preventing said piston rod from rotating relative said cylinder bore.   
     
     
         2 . The wellbore linear actuator of  claim 1 , wherein the piston rod has a non-circular cross-section. 
     
     
         3 . The wellbore linear actuator of  claim 2  wherein the cylinder cap has a non-circular aperture for the piston rod. 
     
     
         4 . The wellbore linear actuator according to  claim 1 , further comprising a tool drain line between said first and second ends,
 wherein said tool drain line is arranged through said cylinder head, said piston head, and said piston rod, and   wherein said tool drain line comprises first and second telescoping tubular elements.   
     
     
         5 . The wellbore linear actuator according to  claim 1 , further comprising an actuate fluid port, arranged at said first or second end,
 wherein said first or second end, opposite said fluid port, is arranged for holding a downhole tool, and   wherein said wellbore linear actuator is arranged for feed-through of hydraulic fluid from said actuate fluid port to said downhole tool.   
     
     
         6 . The wellbore linear actuator according to  claim 5 , further comprising:
 a fluid pump; and   a fluid control circuit interconnecting said fluid pump and said actuate fluid port and arranged for opening and closing a fluid passage between said fluid pump and said first chamber to provide pressurized fluid to said tool and to extend said double acting cylinder when in an open position.   
     
     
         7 . The wellbore linear actuator according to  claim 6 , wherein said wellbore linear actuator comprises a fluid reservoir, and
 wherein said fluid control circuit interconnects said fluid reservoir and said actuate fluid port, and is further arranged for simultaneously opening a fluid passage between said fluid reservoir and said first chamber and for closing said fluid passage between said fluid pump and said first chamber to allow said double acting cylinder to retract.   
     
     
         8 . The wellbore linear actuator according to  claim 1 , further comprising a retract fluid port arranged at said first or second end,
 wherein said double acting cylinder further comprises a retract fluid passage between said retract fluid port and said second chamber.   
     
     
         9 . The wellbore linear actuator according to  claim 8 , wherein, said fluid control circuit interconnects said fluid pump and said retract fluid port and is arranged for opening and closing said retract fluid passage between said fluid pump and said second chamber to actively retract said double acting cylinder. 
     
     
         10 . The wellbore linear actuator according to  claim 1 , wherein, said fluid control circuit is further arranged for simultaneously opening said retract drain fluid passage between said fluid reservoir and said second chamber and for closing said fluid passage between said fluid pump and said second chamber to allow said double acting cylinder to extend. 
     
     
         11 . The wellbore linear actuator of  claim 4 , further comprising an electric connection through said first and second telescoping tubular elements, interconnecting first and second electric terminations arranged in said first and second ends, respectively. 
     
     
         12 . The wellbore linear actuator of  claim 1 , further comprising a telescopic position sensor, arranged through said first and second telescoping tubular elements, and arranged to provide an output value corresponding to a longitudinal position of said piston head within said cylinder bore. 
     
     
         13 . The wellbore linear actuator according to  claim 1 , wherein a retract fluid port is arranged at said first end, and said second end is arranged for holding said downhole tool,
 wherein said wellbore linear actuator comprises a retract fluid line arranged through said cylinder head and slidingly arranged through said piston head, and   wherein said retract fluid line interconnects said second chamber and said retract fluid port.   
     
     
         14 . The wellbore linear actuator according to  claim 1 , wherein a retract fluid port, is arranged at said second end, and said first end is arranged for holding said downhole tool,
 wherein said wellbore linear actuator comprises a retract fluid line longitudinally arranged inside said piston rod, and terminating in an end of said piston rod, opposite said second end, in said second chamber, and   wherein said retract fluid line interconnects said second chamber and said retract fluid port.   
     
     
         15 . A method for providing hydraulic fluid from a hydraulic pump to a rotary downhole tool connected to respective first and second ends of a wellbore linear actuator comprising:
 a double acting cylinder with a cylinder bore,   wherein said double acting cylinder comprises:
 a cylinder head; 
 a cylinder cap opposite said cylinder head; 
 a piston head; and 
 a piston rod, 
   wherein said piston head separates said cylinder bore into a first chamber and a second chamber, and said piston rod extends out of said second chamber through said cylinder cap,   wherein said cylinder head is at said first end and an external end of said piston rod is at said second end, and   wherein said cylinder is configured for preventing said piston rod from rotating relative said cylinder bore,   wherein said method comprises:
 closing a fluid passage between said first chamber and said rotary downhole tool and opening a fluid passage between said hydraulic pump and said first chamber to expand said wellbore linear actuator into position; and 
 opening said fluid passage between said first chamber and said rotary downhole tool to provide hydraulic fluid to said rotary tool. 
   
     
     
         16 . The method of  claim 15 , comprising;
 opening a fluid passage between said second chamber and a fluid reservoir, to expand said wellbore linear actuator into position,   closing said fluid passage between said second chamber and said fluid reservoir, to provide hydraulic fluid to said rotary downhole tool.   
     
     
         17 . The wellbore linear actuator according to  claim 2 , further comprising a tool drain line between said first and second ends,
 wherein said tool drain line is arranged through said cylinder head, said piston head, and said piston rod, and   wherein said tool drain line comprises first and second telescoping tubular elements.   
     
     
         18 . The wellbore linear actuator according to  claim 3 , further comprising a tool drain line between said first and second ends,
 wherein said tool drain line is arranged through said cylinder head, said piston head, and said piston rod, and   wherein said tool drain line comprises first and second telescoping tubular elements.   
     
     
         19 . The wellbore linear actuator according to  claim 2 , further comprising an actuate fluid port, arranged at said first or second end,
 wherein said first or second end, opposite said fluid port, is arranged for holding a downhole tool, and   wherein said wellbore linear actuator is arranged for feed-through of hydraulic fluid from said actuate fluid port to said downhole tool.   
     
     
         20 . The wellbore linear actuator according to  claim 3 , further comprising an actuate fluid port, arranged at said first or second end,
 wherein said first or second end, opposite said fluid port, is arranged for holding a downhole tool, and   wherein said wellbore linear actuator is arranged for feed-through of hydraulic fluid from said actuate fluid port to said downhole tool.