Subsurface Logging Methods 



395 



Z= Distance of center "O" of 

 solenoid system below 

 ground loop 



r= Radius of ground loop 



A= Angle through which the 

 two solenoids are seen fromi 

 ground loop 



A 



Ground Loop 



Of Unit 



Cross Sectional 



Area 



:^^ 





>An?iplifier a 

 '.Oscillator 

 Housing 



\ 

 \ 



\/ • 



/ 



^ / 

 / 



/ 



Figure 176. Elecetrical principle (A) and apparatus (B) used for induction logging. 

 (From Oil and Gas Jour.) 



