354 S. G. KoMAROv and Z. I. Keivsar 



A COMPARISON OF THE RESULTS IN DETERMINING THE PERMEABILITY BY 

 THE SPECIFIC RESISTANCE WITH DATA FOR CORE ANALYSIS 



For a number of strata of Bashkiria, Tataria and Nizhnii Povolzh'e de- 

 posits the values of permeabiHty of the strata determined, according to 

 the instructions (*), from their specific resistance were compared with data 

 on the permeabihty of strata estabhshed by measurements on samples. 



The permeabihty of strata of the Tuimazinskian and Romashkinskian 

 deposits was deterinined by Dolina<^'^)*. The specific resistance of the 

 waterbearing stratum, was taken, as shown above, to be 0.7 O/m. 



Guzanova determined the permeabihty of the strata for the Shkapovskian 

 deposit (^^). The specific resistance of the water-bearing stratum was also 

 taken as being 0.7 Q/m. 



For the Nizhnii Povolzh'e the permeability of the strata was determined 

 by SusLOVA (^^) ; the specific resistance of the water-bearing stratum was 

 determined from the porosity of the strata; the resistance of the stratum 

 water was taken as 0.04 O/m. The permeability of the samples was taken 

 from the data of the appropriate laboratories. 



The permeability from the specific resistance was determined for strata 

 removed from the water— petroleum contact. 



In comparing the results of determining permeability from the specific 

 resistance with the results of core analysis, all the wells, in which samples 

 were taken from the stratum and its specific resistance measured, were se- 

 lected. 



For each well: 



(a) KpQj. tbe permeability derived from the specific resistance according 

 to the curve 3 of Fig. 1 was determined; 



(b) The mean arithmetic value of the permeabihty of the stratum was 

 determined from measuremerxts on samples taken from the sanie well, K ; 



(c) The absolute value for the difference was found 



X = \ K^ ~K^ \ 



■^ 1 ^^per ^^per \ 



Since the values of the permeabihty K^^^ from the large number of 

 determinations are more accurate than the values obtained from a small 

 number of determinations then the "weight" of the difierence x for a differ- 

 ent number of determinations of permeability from the cores will be different. 

 We considered that for four or more determinations, the weight of the 



* From these data the conclusion was previously made that the mean error in deter- 

 mining the permeabihty is close to 20-25% (*). 



