258 I. C. WHITE PETKOLEUM FIELDS OF NORTHEASTERN MEXICO 



Juan Casiano Well No. 7 — Continued 



Feet In. 

 1,175 



Gray shale. 



1,294 



Shell ( underreanied ) . 



1,296 



Gray shale. 



1,342 



Sandy shell (underreamed). 



1,348 



Gray shale. 



1,484 



Shelly. 



1,508 



Gray shale. 



1.538 



Shelly. 



1.556 



Gray shale. 



1,782 



Cable broke (fishing job). 



1,992 



Brown shale. 



2,040 



Gray shale. 



2,070 



Light blue shale, showing of mica. 



2,078 



Gray shale. 



2.106 8 



Landed 10-inch casing. 



2,107 



Lime. 



2,112 



Oil, September 11, 1910. 



Production to April 16, 1913, 20,697,000 barrels, and still flowing 

 22,000 barrels daily under a pressure of 281 pounds. 



Top 



Feet 





20 



Clay. 



45 



Shale. 



65 



Shale. 



85 



Slate. 



105 



Shale. 



165 



Shale. 



175 



Shells. 



190 



Hard shells. 



210 



Slate. 



230 



Shale. 



270 



Shale. 



310 



Shale. 



620 



Shale. 



645 



Mud. 



740 



Shale. 



770 



Slate. 



785 



Shale. 



795 



Slate. 



805 



Shale. 



865 



Shale. 



890 



Shale. 



900 



Slate. 



950 



Slate. 



una 



No. 2 

 Feet 







975 



Slate. 





1,005 



Slate. 





1,040 



Shale. 





1,135 



Slate. 





1,150 



Slate. 





1,165 



Hard slate. 





1,185 



Shells and mud. 





1,215 



Shells. 





1,230 



Shale. 





1,270 



Shale. 





1,290 



Shells. 





1,310 



Struck some oil. 





1.325 



Shale. 





1.330 



Rock. 





1,460 



Shale. 





1,490 



Lime and shale. 





1,500 



Limestone. 





1,505 



Shale. 





1,510 



Limestone. 





1 520 



Lime rock. 





1,544 



Well flowing October 29, 

 1906. 



