Inductive Power Coupler

Abstract

In one aspect of the present invention, a downhole tool string component has a tubular body with at least one end adapted for threaded connection to an adjacent tool string component. The end has at least one shoulder that abuts an adjacent shoulder of an adjacent end of the adjacent tool string component. At least two electrically conducting coils are disposed within an annular recess formed in the at least one shoulder and an annular trough is disposed in the annular recess. The annular trough houses at least one of the at least two electrically conducting coils and each coil is electrically insulated from each other.

1 . A downhole tool string component, comprising:
 a tubular body with at least one end adapted for threaded connection to an adjacent tool string component;   the end comprising at least one shoulder that abuts an adjacent shoulder of an adjacent end of the adjacent tool string component;   at least two electrically conducting coils disposed within an annular recess formed in the at least one shoulder;   an annular trough disposed in the annular recess houses at least one of the at least two electrically conducting coils; and   each coil is electrically insulated from each other.   
     
     
         2 . The component of  claim 1 , wherein the adjacent shoulder comprises at least two adjacent electrically conducting coils and an adjacent annular trough disposed in an adjacent annular recess formed in the adjacent shoulder configured similar to the at least two electrically conducting coils and the annular trough in the downhole tool string component and couple when the downhole components are connected together at their ends, wherein the at least two coils and the at least two adjacent coils induce magnetic fields in each other when the coils are electrically energized. 
     
     
         3 . The component of  claim 1 , wherein the at least two electrically conducting coils and the annular trough are part of a modular unit that plugs into an electrical circuit disposed in the downhole tool string component. 
     
     
         4 . The component of  claim 1 , wherein the annular trough concentrates a magnetic field generated by at least one of the at least two electrically conducting coils. 
     
     
         5 . The component of  claim 1 , wherein a first coil of the at least two electrically conducting coils comprises at least two annular loops. 
     
     
         6 . The component of  claim 5 , wherein the first coil is housed within the annular trough. 
     
     
         7 . The component of  claim 5 , wherein a magnetic current with a frequency of 35 kHz to 150 kHz is emitted from the first coil when the first coil is electrically energized. 
     
     
         8 . The component of  claim 5 , wherein the first coil comprises a positive lead and a negative lead that connects the first coil into an electrical circuit disposed in the downhole tool string component. 
     
     
         9 . The component of  claim 1 , wherein a second coil of the at least two electrically conducting coils comprises a single annular loop. 
     
     
         10 . The component of  claim 9 , wherein the second coil is grounded to the at least one shoulder. 
     
     
         11 . The component of  claim 9 , wherein the second coil is housed within the annular trough. 
     
     
         12 . The component of  claim 9 , wherein the second coil is disposed outside of the annular trough. 
     
     
         13 . The component of  claim 9 , wherein a magnetic current with a frequency of 2 MHz to 7 MHz is emitted from the second coil when the second coil is electrically energized. 
     
     
         14 . The component of  claim 1 , wherein the annular trough comprises segments with a composition alternated between at least two different ferrite alloys. 
     
     
         15 . The component of  claim 1 , wherein an electronic amplifier is disposed in the downhole tool string component that amplifies an electrical signal of at least one of the at least two electrically conducting coils. 
     
     
         16 . The component of  claim 1 , wherein the annular trough comprises a material comprising a composition selected from the group consisting of ferrite, Ni, Fe, Cu, Mo, Mn, Co, Cr, V, C, Si, Zn alloys and combinations thereof. 
     
     
         17 . The component of  claim 1 , wherein the annular trough comprises two side walls and a bottom of uniform thickness. 
     
     
         18 . The component of  claim 1 , wherein a steel housing is disposed within the annular recess and houses the annular trough. 
     
     
         19 . The component of claim  21 , wherein one of the at least two electrically conducting coils is disposed intermediate the steel housing and the annular trough. 
     
     
         20 . An inductive coupler, comprising:
 at least two electrically conducting coils disposed within an annular recess;   an annular trough disposed in the annular recess houses at least one of the at least two electrically conducting coils; and   each coil is electrically insulated from each other.