SOME SUGGESTIONS FOR INDICATING DRILLING 
OPERATIONS 
MAURICE G. MEHL 
No doubt it has occurred to all who make use of maps show- 
ing drilling operations, that the symbols used for this purpose 
are not entirely satisfactory. Mr. E. G. Woodruff recently 
called attention to the advantages in the uniform use of sym- 
bols in a paper entitled Notebook form and symbols for petro- 
leum geologists. 1 A few illustrations will serve to emphasize the 
need for improvement in the methods for describing petroleum 
and gas development graphically. 
4. b. c. d. e. f. g. h, L J, A 
Fig. 1 
There seems to be no agreement among geologists, drafts- 
men, and others responsible for the symbols as to how a certain 
feature, a gas well, for instance, shall be designated. Most state 
geological surveys have designs of their own selection, and even 
the geologist as an individual is sometimes partial to a set of 
symbols that is distinctive rather than useful. Unfortunately, 
there seems to be no assurance that a design, once having been 
selected for a certain feature, will be used consistently by its 
author. The accompanying designs (fig. 1) will give some idea of 
the great variety in the symbols used for a single feature. As 
the source from which these designs were compiled does not 
include private reports, the list is in no manner complete. 
Adding to the confusion is the common practice of using the 
same design to describe many different features. The symbol 
1 Economic Geology, vol. 14, no. 5, p. 424, 1919. 
169 
