THE PERMEABILITY OF OIL-BEARING STRATA 



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to values which did not correspond to the actual values for the permeabiHty 

 (Table 4). 



Tliis is due to the fact that the most probable values for the coefficient of 

 increase in resistance of a number of deposits is much less than the most 

 probable value of the coefficient of the increase in resistance for the Devonian 

 sandstone of the Bashldrian and Tatarian deposits (Fig. 8). 



Fig. 7. A comparison of the values of the coefficient for the increase in resistance 



with permeability for different porosities. Tuimazinskian deposit, stratum i)j. Circles — 



porosity up to 19%; black points — porosity above 22%; the curve corresponds to the 



dependence Q = /{Kp^j) for the Z)j stratum (according to Fig. 5). 



The followng conclusions can be drawn from a consideration of Figs. 6 

 and 8. 



1. For different strata there are different curves for the dependence of 

 the coefficient of increase in resistance on the permeability. Even for the 

 Devonian sandstone, and in the same oil field the difference between the 

 curves Q = f{K ) is so great that for each stratum, it is necessary 

 to use its own curve for the dependence of the coefficient of increase in 

 resistance on the permeability. 



The reasons for the difference between the curves Q ^f{Kp^^) for 

 different strata are: 



(a) The difference in the values for the interstitial water saturation of 

 separate strata and in the character for the change in the interstitial water 

 saturation on the permeability; 



(b) The absence of a unique dependence of the coefficient of increase 



Applied geophysics 24 



