COMPOSITION OF THE OIL-FIELD WATERS. 63 
Table 4. —Analyses of normal ground water (“top water 1 ') from wells in the Coalinga 
and Midway oil fields , Cal. 
22 
23 
24 
25 
26 
PROPERTIES OF REACTION IN PER CENT. 
Primary salinity.. 
Secondary salinity.. 
Primary alkalinity.. 
Secondary alkalinity.. 
Per cent of rS0 4 in rS0 4 +rCl. 
Ratio of rCC> 3 +rHC 03 to rS 0 4 . 
CONSTITUENTS IN PARTS PER MILLION. 
59.2 
28.4 
0 
12.4 
77.7 
.18 
92.4 
0 
2.0 
5.6 
92.4 
.09 
53.8 
35.6 
0 
10.6 
78.3 
.15 
94.0 
5.4 
0 
.6 
7.0 
.08 
90.2 
3.4 
0 
6.4 
30.6 
.22 
Sodium (Na). 
Potassium (K).. 
Calcium (Ca). 
Magnesium (Mg). 
Iron oxide (Fe 2 0 3 ) and alumina (Al 2 O a ) 
Sulphate (S0 4 ). 
Chloride (Cl). 
Carbonate (CO 3 ). 
Bicarbonate (HCO3). 
Silica (Si0 2 ). 
a 442 
al,335 
a 661 
08 ,794 
140 
76 
6 39 
1,062 
226 
6 121 
34 
22 
2,518 
154 
b 141 
249 
148 
6 105 
1,793 
368 
6 169 
397 
61 
6 2.4 
1,381 
13,304 
6 71 
17 
45 
911 
8.4 
23 
39 
605 
1,013 
0 
175 
32 
Hydrogen sulphide (H 2 S). 
REACTING VALUES IN PER CENT. 
Alkalies: 
Sodium (rNa). 
Potassium (rK). 
Alkaline earths: 
Calcium (rCa). 
Magnesium (rMg). 
Strong acids: 
Sulphate (rS0 4 ). 
Chloride (rCl). 
Weak acids: 
Carbonate (rCOs). 
Bicarbonate (rHCC> 3 ). 
ANALYSIS AS REPORTED. C 
2,106 
o29.6 
10.7 
9.7 
34.0 
9.8 
6 6.2 
4,221 
o47.2 
1.4 
1.4 
42.7 
3.5 
6 3.8 
3,493 
o26.9 
11.6 
11.5 
35.0 
9.7 
6 5.3 
24,055.4 
o 47.0 
2.4 
.6 
3.5 
46.2 
6.3 
2,717.4 
Present 
44.7 
.4 
1.3 
3.6 
14 
32 
.0 
3.2 
Sodium sulphate. 
Sodium chloride.. 
Sodium carbonate 
53.33 
21.74 
217.70 
14.83 
3.59 
76.10 25.95 
35.46 1,282.50 
Calcium sulphate. 
Calcium carbonate. 
Magnesium sulphate.... 
Magnesium carbonate.., 
Iron oxide and alumina 
14.84 . 
9.47 5.00 
19.44 . 
1.92 4.48 
2.27 . 
Silica 
.98 
33.01 
12.07 
37.62 
69.42 
6.92 
17.75 
3.67 . 
6.12 .14 
. 2.65 
123.01 
246.58 
204.05 
1,405.33 
a Reported and calculated as sodium but includes potassium. 
6 Reported and calculated as carbonate but probably in part bicarbonate, 
c In hypothetic combinations, in grains per U. S. gallon. 
Coalinga field: 
22, 23, and 24. Kern Trading & Oil Co. wells in sec. 25, T. 20 S., R. 14 E. Nos. 22 and 23 represent 
water which corroded the casing and temporarily flooded the wells. The water certainly occurs 
above the oil and probably more than 500 feet above it. No. 24 represents water from a depth 
of 648 feet, or just above the zone of tar sands and 480 feet above the oil. Analyst, Kern Trading 
& Oil Co. 
Midway field: 
25. Standard Oil Co. well 6, sec. 12, T. 32 S., R. 23 E. Water is from 670 to 730 feet, or about 2,000 
feet above the horizon of the oil. Analyst, Standard Oil Co. January, 1912. 
26. August Water Co., California Amalgamated well 2, sec. 35, T. 32 S., R. 23 E. Sulphur water from 
1,090 feet, probably in shale of Monterey group. Temperature, 84° F. (See p. 19.) Sampled 
by G. S. Rogers, July, 1914. Analyst, Chase Palmer. 
I 
