Drilling Rig System Having Improved Electrical Subsystem

Abstract

In embodiments, a drilling rig system includes a rig unit having rig equipment and a rig electrical subsystem configured for electrical communication with the rig equipment and including a rig electrical subsystem input transformer, an electrical system including a primary power supply subsystem remote from the rig unit, and an intermediate electrical subsystem.

What is claimed is: 
     
         1 . A drilling rig power system comprising:
 a movable rig electrical subsystem electrically coupled to a plurality of rig equipment, the movable rig electrical subsystem comprising a rig electrical subsystem input transformer for transforming intermediate power at a high voltage to rig power at a voltage that is less than the high voltage;   a stationary primary power supply subsystem remote from the movable rig electrical subsystem; and   an intermediate electrical subsystem comprising an intermediate subsystem input transformer electrically coupled to the stationary primary power supply subsystem for transforming primary power at another voltage that is less than the high voltage of the intermediate power to the high voltage of the intermediate power, and an intermediate conductor electrically coupled to the intermediate subsystem input transformer and the rig electrical subsystem input transformer.   
     
     
         2 . The drilling rig power system of  claim 1 , wherein the another voltage of the primary power is at or below 690 Volts AC, and the high voltage of the intermediate power is at or above 2300 Volts AC. 
     
     
         3 . The drilling rig power system of  claim 1 , wherein the voltage of the rig power is at or below 690 Volts AC. 
     
     
         4 . The drilling rig power system of  claim 1 , wherein the intermediate conductor comprises no more than a set of conductor members for carrying three-phase electrical current. 
     
     
         5 . The drilling rig power system of  claim 1 , wherein the intermediate electrical subsystem comprises another intermediate conductor electrically coupled to the intermediate subsystem input transformer and the rig electrical subsystem input transformer. 
     
     
         6 . The drilling rig power system of  claim 1 , wherein the intermediate electrical subsystem comprises a conductor carrier reel configured to support the intermediate conductor for rotation about a conductor carrier reel axis during extension or retraction of the intermediate conductor. 
     
     
         7 . A drilling rig power system comprising:
 a movable rig electrical subsystem electrically coupled to a plurality of rig equipment, the movable rig electrical subsystem comprising a rig electrical subsystem input transformer;   a stationary primary power supply subsystem remote from the movable rig electrical subsystem; and   an intermediate electrical subsystem comprising no more than two three-phase intermediate conductors electrically coupled to the stationary primary power supply subsystem and the rig electrical subsystem input transformer.   
     
     
         8 . The drilling rig power system of  claim 7 , wherein the intermediate electrical subsystem enables the movable rig electrical subsystem to travel away from the stationary primary power supply subsystem while maintaining electrical communication with the stationary primary power supply subsystem. 
     
     
         9 . The drilling rig power system of  claim 7 , wherein the no more than two three-phase intermediate conductors are retractable to enable the movable rig electrical subsystem to travel toward the stationary primary power supply subsystem while maintaining electrical communication with the stationary primary power supply subsystem. 
     
     
         10 . The drilling rig power system of  claim 7 , wherein the no more than two three-phase intermediate conductors are configured to carry intermediate power at a high voltage. 
     
     
         11 . The drilling rig power system of  claim 7 , wherein at least one of the no more than two three-phase intermediate conductors is included in a composite intermediate cable structure that comprises the intermediate conductor and a control cable for communicating data between a rig unit and subsystems remote from the rig unit. 
     
     
         12 . The drilling rig power system of  claim 7 , wherein the rig electrical subsystem input transformer transforms intermediate power received through the no more than two three-phase intermediate conductors at a high voltage to rig power at a voltage lower than the high voltage. 
     
     
         13 . The drilling rig power system of  claim 7 , wherein the intermediate electrical subsystem comprises a conductor carrier reel configured to support the no more than two three-phase intermediate conductors for rotation about a conductor carrier reel axis during extension or retraction of the intermediate conductor. 
     
     
         14 . A method of powering a movable drilling rig unit, comprising:
 transmitting primary power at a voltage that is less than a high voltage from a stationary power supply subsystem to an intermediate subsystem input transformer;   transforming the primary power at the intermediate subsystem input transformer into intermediate power at the high voltage;   transmitting the intermediate power from the intermediate subsystem input transformer to a rig electrical subsystem input transformer on the movable drilling rig unit through a high voltage intermediate conductor;   transforming the intermediate power at the rig electrical subsystem input transformer into rig power at another voltage that is lower than the high voltage; and   transmitting the rig power from the rig electrical subsystem input transformer to a plurality of rig equipment on the movable drilling rig unit.   
     
     
         15 . The method  claim 14 , wherein the another voltage of the primary power is at or below 690 Volts AC, and the high voltage of the intermediate power is at or above 2300 Volts AC. 
     
     
         16 . The method  claim 14 , wherein the voltage of the rig power is at or below 690 Volts AC. 
     
     
         17 . The method  claim 14 , wherein the high voltage intermediate conductor comprises no more than a set of conductor members for carrying three-phase electrical current. 
     
     
         18 . The method  claim 14 , comprising:
 transmitting the intermediate power from the intermediate subsystem input transformer to the rig electrical subsystem input transformer on the movable drilling rig unit through an additional high voltage intermediate conductor.   
     
     
         19 . A method of powering a movable drilling rig unit, comprising:
 transmitting primary power from a stationary power supply subsystem to a plurality of rig equipment on a moveable drilling rig unit through no more than two three-phase intermediate conductors.   
     
     
         20 . The method of  claim 19 , comprising:
 supporting the no more than two three-phase intermediate conductors on a conductor carrier reel for rotation about a conductor carrier reel axis during extension or retraction of the no more than two three-phase intermediate conductors.