Device and method for using the device for "in situ" extraction of bitumen or ultraheavy oil from oil sand deposits

Abstract

The device has at least one electrical conductor loop formed of a feed conductor, a return conductor and an inductor connected therebetween. At least the inductor is at least partially or completely disposed in the oil sand deposit. The device further has an alternating current generator that is electrically connected to the at least one conductor loop by at least two electrical contact points. The alternating current generator has a transformer with at least one primary and at least one secondary winding. The at least one secondary winding comprises a center tap to which a ground potential U e is electrically connected.

1 - 12 . (canceled) 
     
     
         13 . A device for in situ extraction of bitumen or ultraheavy oil from oil sand deposits, comprising:
 at least one electrical conductor loop, each including a forward conductor, a return conductor and an inductor connected between the forward conductor and the return conductor, at least the inductor being arranged at least partially in the oil sound deposit; and   an AC generator, electrically connected to the at least one conductor loop via at least two electrical contact points, the AC generator including a transformer having at least one primary winding and at least one secondary winding, the at least one secondary winding having a center tap to which a ground potential is applied electrically.   
     
     
         14 . The device as claimed in  claim 13 , wherein the ground potential is applied one of passively to the center tap electrically via a galvanic connection, and actively to the center tap using circuitry via an electrical circuit. 
     
     
         15 . A device for in situ extraction of bitumen or ultraheavy oil from oil sand deposits, comprising:
 at least one electrical conductor loop, each including a forward conductor, a return conductor and an inductor connected between the forward conductor and the return conductor, at least the inductor being arranged at least partially in the oil sound deposit; and   an AC generator, electrically connected to the at least one conductor loop via at least two electrical contact points, the AC generator including a transformer having at least one primary winding and at least one secondary winding, the at least one secondary winding, a ground potential being applied electrically to the conductor loop at a point spatially removed from the AC generator.   
     
     
         16 . The device as claimed in  claim 15 , wherein the ground potential is applied spatially on the inductor at a furthest point on the conductor loop from the AC generator. 
     
     
         17 . The device as claimed in  claim 16 , wherein the AC generator applies a voltage of at least 10 kV via the inductor that inductively heats the oil sand deposit. 
     
     
         18 . The device as claimed in  claim 17 , wherein the transformer is a matching transformer the voltage of at least 10 kV. 
     
     
         19 . The device as claimed in  claim 18 , wherein the inductor has a length greater than 1 km 
     
     
         20 . The device as claimed in  claim 19 , wherein the inductor has a length greater than 5 km. 
     
     
         21 . The device as claimed in  claim 19 , wherein, except for where the ground potential has been applied, the electrical conductor loop is electrically insulated completely from the oil sand deposit, so that application of the ground potential results in heating of the oil sand deposit via the electrical conductor loop purely inductively. 
     
     
         22 . The device as claimed in  claim 21 ,
 further comprising power converters electrically connected to the primary winding, and   wherein the at least one primary winding is DC-isolated from the at least one secondary winding.   
     
     
         23 . The device as claimed in  claim 22 , wherein the AC generator is an HF generator with an electrical power of greater than 1 MW at 5 to 200 kHz 
     
     
         24 . The device as claimed in  claim 23 , wherein the AC generator is an HF generator with an electrical power of greater than 1 MW at substantially 50 kHz. 
     
     
         25 . A method for in situ extraction of bitumen or ultraheavy oil from oil sand deposits, comprising:
 installing a device with at least one electrical conductor loop, each including a forward conductor, a return conductor and an inductor connected between the forward conductor and the return conductor, at least the inductor being arranged at least partially in the oil sound deposit;   and an AC generator, electrically connected to the at least one conductor loop via at least two electrical contact points, the AC generator including a transformer having at least one primary winding and at least one secondary winding, the at least one secondary winding having a center tap; and   applying the ground potential at one of the center tap of the secondary winding and a point on the conductor loop spatially removed from the AC generator, so that a voltage between the at least two electrical contact points is lower than an output voltage without the ground potential applied.   
     
     
         26 . The method as claimed in  claim 23 , wherein said applying results in the voltage between the at least two electrical contact points being substantially half the output voltage without the ground potential applied.