INTRODUCTION. 
7 
the system of interpretation of water analyses adopted in this report, 
have been freely consulted, and Dr. Palmer in particular has been a 
constant source of help in the study of the chemical relations of water 
and oil. The writer is indebted also to Mr. It. B. Dole for generous 
consultation on some of the problems touching the chemistry of 
natural waters. Dr. Chase Palmer and Mr. S. C. Dinsmore made 
many of the water analyses included in the report. 
Special mention should be made of the unpublished work of Mr. E. 
A. Starke, of the Standard Oil Co., on the chemistry of the waters of 
the California oil fields. Mr. Starke has collected and studied a large 
number of water analyses and reached several years ago many of the 
conclusions that the writer has recently arrived at independently. 
Mr. Starke noted the absence of sulphate in waters associated with 
oil and ascribed it to chemical reaction between the two, and so has 
guided his prospecting to a considerable extent by studying the com¬ 
position of the waters encountered in prospect wells. The special 
thanks of the writer are due Mr. Starke for his free discussion of the 
subject and for the use of some of the analyses included in this report. 
The success of any study of underground conditions in an oil field 
depends on the good will and courtesy of the operators, and the 
writer desires gratefully to acknowledge the support and cooperation 
of all the companies visited. A complete list of those who have 
cheerfully and generously furnished information would include 
practically all the operators in the Coalinga, Midway, and Sunset 
fields, many of whom spent considerable time in assisting in the col¬ 
lection of samples of water for analysis. The following gentlemen 
rendered the writer especially valuable aid: Messrs. B. H. van der 
Linden, M. E. Lombardi, E. G. Gaylord, Paul Paine, M. J. Kirwan, 
W. W. Orcutt, M. L. Requa, T. A. O’Donnell, E. O. Faulkner, W. M. 
Wallace, J. E. Elliot, W. A. Ambrose, F. B. Tough, J. J. Hern, R. D. 
Bush, T. J. Crumpton, W. A. Greer, W. E. Brown, and J. H. Dearin. 
NEED FOR MORE ANALYSES. 
In the course of this investigation more than 50 samples of water have 
been specially analyzed and about 250 analyses, most of them made 
for industrial purposes, have been furnished by the oil companies. 
These have been sufficient, it is believed, to form a fair basis for the 
principles set forth in this paper, but they are inadequate to give 
more than a general idea as to the character of the waters in any par¬ 
ticular locality. In the Westside Coalinga field all the evidence leads 
to the conclusion that conditions are fairly constant, and that even 
with the data at hand it is possible to determine the general horizon 
of a water from its analysis. In the Midway-Sunset field, however, 
the zone of water altered by the oil may in some localities extend 600 
feet above the oil measures, and it is at present impossible to deter- 
