74 
OIL FIELDS OF TEXAS-LOUISIANA COASTAL PLAIN, [bull.212. 
tory. Or the failure to find the oil rock in any of the wells outside 
the proved field may be due to a combination of these causes. 
The second section, B — B, is upon a line N. 15° E., coinciding approx- 
imately with the long axis of the pool. It shows very clearly the 
arching of the strata in this direction. About 1,100 feet beyond the 
Denver and Beaumont well, toward the northeast, is the Big Jumbo, a 
dry hole, which stopped, after passing 14 feet into limestone, at a 
depth of 2,000 feet. This is not certainly identified as either the cap 
or oil rock, but probably represents approximate^ the horizon of the 
latter, which would indicate a steep dip, about 40°, immediately 
beyond the margin of the productive territory. The same indications 
of very steep dips away from the pool are afforded by all the dry 
wells which have been drilled immediately about its margin. 
WELL SECTIONS. 
Several sections of wells in the Spindletop pool have already been 
published, notably that of the original Lucas well. Considering the 
number of wells drilled in this small area, very few logs having any 
degree of accuracy are obtainable. The method employed in drill- 
ing — by means of the rotary drill, which is described on a subsequent 
page — does not favor the keeping of accurate records. The only 
means which the driller has of determining the character of the mate- 
rial which he is passing through is its relative hardness and the 
material brought up by the return-water flow. By the caving in of 
the sides of the hole below the casing any soft material which lias 
been passed through and not cased off may be brought up, and not 
necessarily represent the bed at the bottom of the well, but a mixture 
of materials from various depths. A few logs have been kept with as 
much accurac}^ as the method of drilling permitted, and two of these 
will be given, chiefly to indicate the extreme variability of the 
materials overlying the oil horizon. 
Log of the Geyaer-Kaltenbaeh well, block S3, Spindletop. 
[Elevation, 25 feet.] 
Character of strata. 
Yellow clay 
Quicksand 
Blue clay 
Quicksand. 
Coarse gravel _ . 
Blue clay 
Hard blue shale 
Blue clay 
Coarse gravel - 
Blue clay 
Thickness. 
From— 
Feet. 
Feet. 
20 

36 
20 
134 
50 
105 
190 
20 
295 
10 
315 
4 
325 
51 
329 
17 
380 
13 
397 
To- 
Feet. 
20 
56 
190 
295 
315 
325 
329 
380 
397 
410 
