350 S. G. KoMAROv AND Z. I. Keivsar 



where q^ is the specific resistance of the stratum; 



Q^is the specific resistance of this stratum Avith 100% filhng of itp> 

 pores by water (water-bearing stratum). 



The specific resistance of the oil-bearing stratum q^, necessary for calcul- 

 ating the coefficient of increase in resistance Q, is determined from the data, 

 of VKZ*. 



The specific resistance of the water-bearing stratum is calculated for the- 

 formula 



9w=^Qs.w (2> 



\vhere q^ ^ is the resistance of the stratum Avater, at the temperature of the- 

 stratum ; 



F is the relative resistance of the rock. 



The stratum water of the Devonian sandstones of the Uralo-Volzhsk pro- 

 vince has about 260 g/1. of salts; in agreement with this its specific resis- 

 tance can be taken as being equal to 0.034 D/m at a temperature of 30'^ 

 (according to Morozov 0.03 O/m^^^), according to Dolina 0.05 Q/m(^*)). 



To determine the relative resistance of the Devonian sandstones according 

 to their porosity Dolina recommends (^) the use of the relationship ob- 

 tained from the results in determining porosity of pores and the VKZ data 

 in structure contoured wells; 



F = 0.65m-^'^\ (3> 



where m is the coefficient of porosity in relative units. 



For this purpose, it is also possible to use other results (^'■'^°). 



For comparatively homogeneous strata in the absence of results on the 

 porosity of the stratum, the specific resistance of the water-bearing stratum. 

 Q^j^ is taken as the average value of the resistance of the stratum for the struc- 

 ture contoured wells. 



Thus, Dolina, at one of the Tataria deposits, from the VKZ results for 

 154 structure contoured wells obtained an average value for the resistance- 

 of the water-bearing Devonian sandstone of 0.7 Q/m. This value was 

 recommended for use in calculating the coefficient of increase in resistance. 



The coefficient of water saturation is determined from the coefficient of 

 increase in resistance Q from the curve Q ^f{K^), obtained on the basis- 

 of experimental studies of rock samples. 



It is assumed that the water contained in an oil-bearing stratum cannot 

 take part in the general movement of the liquid in the stratum and is inter- 

 stitial (connate). In this case, the water saturation determined from the curve 

 Q =f{K^) is the residual interstitial water saturation -K^^. id- 



* VKZ — All-Union Commission on mineral Resom-ces. 



