The nomenclature of the oil fields has many unique names and strange uses for old words. Drillers from different parts of the country meeting on the same ground find themselves using differ ent expressions for the same thing, as the Texan's use of 'gumbo' for the Pennsylvanian's 'sticky clay,' and the latter's for the Texan's 'rock,' both meaning any hard substance. Such lo calisms have resulted in there being no common tongue in the description of material drilled, and the knowledge of what these expressions may mean is rather necessary to a complete interpre tation of the usual log.
Logs may be compiled from daily drilling reports where they are in use. Where they are not, the log is usually kept in a note book by the drillers or the foreman. The use of drilling reports, however, is far more satisfactory, especially if supplemented by a diary kept by the superintendent. The usual shift in oil field work is twelve hours, from noon till midnight, and from midnight till noon ; two reports, one for each crew, show the advance made during the day and such other information as is desired. These blanks are printed in triplicate and bound into books of 50 or 100 sets; two copies are torn from the book and turned in at the end of the 'tower,' the oil field term for shift. One copy goes to the main office, the other remains at field headquarters, the third stays with the book at the well.
When wells have been completed, the best manner of compil ing the logs for future reference is some form of graphic represen tation. This may be an elaborately colored drawing, or a more
simple sketch, prepared on tracing cloth so that blue prints may be taken from it, along the lines of the typical log shown in Fig. 30, which embodies all the information necessary for ordinary reference.
When several wells have been drilled in a neighborhood, the use of models, very similar to those prepared at mines to show the positions of orebodies, will bring out the features of the under ground geology, particularly the dip and strike of oil sands. One may easily be made by letting a horizontal hoard represent any datum plane higher than the highest point on the property ; the positions of the wells are then platted to scale on the board, holes drilled through it at these points and long round wooden pegs, rep resenting the wells, slipped into• the holes (Fig. 31). On the pegs are painted in various colors the data to be shown, such as eleva tion of land surface at well, depths of water sands, tar and oil sands, etc., at a scale of either one or two inches to the hundred feet. The same may be shown pictorially, if desired, in a stereographic projection similar to that in Fig. 32, which is a record of the same data shown in the model in Fig. 31 ; this latter method is one fol lowed by many of the larger companies.