COMPOSITION OF THE OIL-FIELD WATERS. 
59 
Table 2. —Analyses of normal ground water from shallow-water wells in the Coalinga, 
Midway , and Sunset oil fields, Cal. 
PROPERTIES OF REACTION IN PER CENT. 
Primary salinity. 
Secondary salinity. 
Primary alkalinity. 
Secondary alkalinity. 
Per cent of rS0 4 in rS0 4 +rCI. 
CONSTITUENTS IN PARTS PER MILLION. 
Sodium (Na). 
Potassium (K). 
Calcium (Ca). 
Magnesium (Mg). 
Sulphate (S0 4 ). 
Chloride (Cl). 
Carbonate (C0 3 ). 
Bicarbonate (HC0 3 ). 
Silica (SiOg). 
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 (rC0 3 ). 
Bicarbonate (rHC0 3 ). 
ANALYSIS AS REPORTED, c 
Sodium sulphate. 
Sodium chloride. 
Sodium carbonate. 
Calcium sulphate. 
Calcium carbonate. 
Magnesium sulphate.... 
Magnesium carbonate... 
Iron oxide and alumina. 
Silica. 
8 
9 
10 
11 
12 
13 
14 
78.0 
80.2 
72 
37.2 
58.2 
76.0 
87.4 
4.2 
.0 
25 
43.4 
37.6 
12.6 
0 
.0 
1.8 
0 
.0 
0 
0 
3.4 
17.8 
18.0 
3 
19.4 
4.2 
11.4 
9.2 
88.5 
87.0 
79 
72.7 
43.6 
26.6 
60.2 
a 470 
a 457 
a 981 
a 198 
a 980 
a 254 
719 
9.5 
59 
45 
297 
166 
257 
61 
39 
34 
26 
21 
75 
217 
6 
22 
Trace. 
7 
48 
3.3 
914 
814 
2,177 
649 
1,473 
166 
879 
88 
88 
423 
180 
1,399 
335 
429 
6 140 
6 143 
6 54 
6 134 
6 91 
6 51 
32 
170 
44 
61 
21 
45 
26 
44 
1,749 
1,641 
4,022 
1,402 
4, 465.3 
899 
2,257.5 
a 39.0 
a 41.0 
a 36.0 
a 18.6 
a 29.1 
38.0 
45.0 
.4 
5.6 
4.6 
12.5 
18.0 
8.7 
10.3 
2.8 
5.4 
4.4 
1.5 
13.4 
12.2 
1.7 
2.6 
36.4 
35.0 
38.4 
29.3 
20.9 
11.8 
26.3 
4.7 
5.1 
10.1 
11.0 
27.0 
32.5 
17.4 
6 8.9 
6 9-9 
61.5 
6 9.7 
6 2.1 
5.7 
1.5 
4.0 
74 30 
70.35 
126.49 
14.56 
11.03 
8.48 
8.50 
40.82 
17.40 
134.91 
1.27 
.58 
1.20 
55.96 
15.20 
45.78 
8 56 
6.60 
2.19 
13.10 
3.79 
4 01 
2.96 
21.70 
57.95 
4 22 
5.20 
2.17 
3.36 
.41 
1.25 
.19 
2.56 
3.57 
2.82 
2.62 
102.13 
95.90 
235.24 
81.96 
260.83 
a Reported and calculated as sodium but includes potassium. 
b Reported and calculated as carbonate but probably in part bicarbonate, 
c In hypothetic combinations, in grains per U. S. gallon. 
Coalmga fielded Qfl Cq water well 3> seC- 2 8, T. 19 S., R. 15 E. Analyst, Standard Oil Co., September, 
9. Standard Oil Co. water well 2, sec. 36, T. 19 S., R. 15 E. Depth, 444 ieet. Analyst, Standard 
10. Associated Pipeline Co., shallow water well at station 1, sec. 18, T. 20 S.,R. 15 E. Analyst, Smith, 
Emery & Co. Authority, Associated Oil Co. • , ^ j T , 
11. Traders Oil Co. water well, sec. 24, T. 20 S., R. 14 E. Depth, 85 feet. Analyst, L. J. Stabler, 
May, 1909. Authority, Traders Oil Co - m „ ,, .. „ . . . „ ... „ £ n 
12. California Oil & Gas Co., water well 1, sec. 6, T. 21 S., R. 15 E. Analyst, Smith Emery & Co. 
MidwayanBJunsetfieWs.. gec> 5> T 31 s> R 25 E. Analyst, Kern Trading & Oil Co., Jan. 1, 
1913 
14 Midway Northern Oil Co. water well, sec. 32, T. 12 N., R. 23 W. Water from sands at 350 and 
790 feet. Sampled by G. S. Rogers, August, 1914. Analyst, Chase 1 aimer. 
Most of these waters may be readily distinguished from surface 
waters, but their distinction from the modified waters beneath 
them is less easy. As shown by figure 4, the shallower waters are 
