NEW TYPES OF WELL RESISTIVITY-METERS 



387 



Av^ is the potential difference between the electrodes M^ and A^^ 

 of the probe placed along the x axis. (The same current was 

 used). 

 x\s a consequence of these observations it was established that the value of 

 y changes from 7 to 10 with the change of the specific resistance of the 

 fluid from 0.5-20 D m, confirming the notion that a rearrangement of the 

 electric field is caused by changes in the salinity of the fluid. In the quoted 

 example, judging from the nature of the change of y, it follows that, as 

 salinity of the fluid decreases the current -density along the x axis decreases 

 in comparison ^vi^h the current density along the z axis. 



0-06 



005 



004 



003 



0-02 



6 8 0-1 



Fig, 1. The dependence of the well resistivity-meter coefficients on the specific electric 

 resistance of the fluid. 1 — REU type of resistivity-meter; 2 — RA-3 type of a serial 

 resistivity -meter; 3— PTL VOGSGT (Ufa) serial resistivity -meter ;4-GML BGK (Ufa) 

 serial resistivity-meter. 



The reason for the rearrangement of the field with the change in the sahn- 

 ity of the fluid should, evidently, be sought in the phenomena which occur 

 at the electrolite -metal interface, and in particular in the so-called contact 

 resistance of this boundary. 



The contact resistance is not proportional to the specific resistance of the 

 electrolite and with the decrease in the salinity of the fluid the contact 

 resistance increases much less than the specific resistance. It is this that 

 causes a rearrangement of the electric field consequent upon a change in the 

 specific resistance of the fluid. 



25* 



