156 Crt, METELND 
productive horizon both are seen to decline rapidly in resistivity 
toward the edge of the productive zone. 

in chs m?m 

Pesistivities 


j 3 gE A jf Bi i g j 
Fic. 37.—High resistivity of two producing sands, Wewoka field, Seminole 2rea, 
Qxlahoma, 1929. (Peney Reed No. 1.) (After Schlumberger.) 

Resistivitrses a) 




oon Suse Book: oot aor aor @or 
Disteace between wolle a feet ond 
8 
«0 z 
6 . 9 
: = i 
001 & : L 
ra} = c. # 5 
1200 x We = , 
i “ a I ‘ 
% “ 
1200 =e g > Ls fee 
“= Ya fe D> UL 4 
= > an PWS. 
Ca o- gt 9 aes 
1400 | 7 zi B, a 
= V2t—— neo 
F LS wer’ wso. erie” 
A 
Fal let Bn Ky wsad eee H 
A BA vA pee 
bs a 
es nd , as 
000 bys 8 
wso se 
Sooo te un mores wSO C 
9 
2200 
7. 
~orred WSO 
Fic. 38.—Electrical correlations between wells in the Maracaibo field, Venezuela. 
(After Schlumberger.) 
2. ELECTRICAL VERTICAL DRILLING IN DIRECT PROSPECTING FOR OIL 
If it is possible to recognize oil-bearing beds in wells in such indis- 
putable manner, is it not possible to get the same or similar results by 
measurements from the surface? The results obtained thus far in ap- 
proaching a solution of this problem will now be discussed. 
486 
