fuller] IMPORTANCE OF ACCURATE WELL RECORDS. 13 
the shaft o»- drill can c^termine the occurrence and nature of the 
changes in question. 
The shaft is of immense value in restricted areas, but it is the widely 
distributed and of ten deep borings that afford information in regard 
to the broader features of interest to the driller, to the operator in 
search of oil, gas, or brines, and to manufacturers and others seeking 
artesian waters. 
The importance of accurate records of borings was early recognized 
by the more enterprising of the drillers and by certain companies 
operating in oil and gas, and the success of such drillers and operators 
has been to a considerable extent due to their recognition of the 
importance of the precise information afforded by the borings, their 
insistence that records be kept, and their attention to other similar 
details, minor in themselves but often sufficiently important in the 
aggregate to make the difference between failure and success. It is 
probable that there is now not one successful operator on a large scale 
who does not require the keeping of at least partial records. 
Among the many ways in which well records are of value the fol- 
lowing may be mentioned: To the oil and gas driller they furnish 
information as to (1) the best point for locating the well, (2) the depth 
of the supposed productive bed, (3) the character of the material to be 
penetrated, (4) the amount of water which will be encountered, (5) the 
amount of easing required, and (6) the limit of depth to w T hich it is 
desirable to drill. To the owners of such wells information as to each 
of the foregoing points, especially those affecting the cost of the wells, 
is furnished by the records, in addition to which data relating to still 
more important factors, namely, those of quantity and quality of sup- 
plies, are furnished. In the case of drillers and owners of water wells 
the same information is supplied, but here the items affecting the cost 
are of increased importance owing to the lower value of the product, 
and questions of head, quantity, and quality of supply again come to 
the fore. To prospective owners records show the results obtained 
by others and the probabilities of success of new ventures, while to 
the geologist they are of value in assisting him to a more thorough 
understanding of the geology, which in turn enables him to more 
intelligently answer the numerous questions constantly referred to 
him by drillers, well owners, and others. 
A more detailed statement concerning the uses of records is given 
in the following paragraphs, with the view of presenting their benefits 
more fully to those drillers and owners, especially the smaller oper- 
ators, who do not have the facilities of the larger companies for col- 
lecting and preserving their own records, but who by furnishing 
information can assist the Survey to a knowledge of the various 
regions, and thus enable it in turn to give them the benetit of the 
results of the studies of its geologists. 
