392 F. H. OLIPHANT 



has enabled the operator to pump economically small wells 

 that otherwise could not be operated, and it has also enabled 

 him to handle large quantities of water where petroleum must 

 be secured at a small outlay. Petroleum wells are often pump- 

 ed in clusters of from 5 to 25, the number varying according 

 to the depth and other conditions. Where the wells are com- 

 paratively shallow, and not too far apart, they can be pumped 

 readily and with small loss by means of rods operated by steam 

 or gas engines. Formerly deep wells were operated by a single 

 boiler in or near the center of a cluster of from 4 to 6 wells, 

 each of which had a steam engine connected with steam pipes 

 radiating from this boiler. The loss by condensation when 

 this method was used was very great. 



The gas engine has in many instances replaced the steam 

 engine, the change often being effected by the removal of the 

 steam cylinder and the substitution of a gas cylinder. The 

 boiler is dispensed with. The gas engine will run unattended 

 for hours, as it is only necessary that it be kept lubricated. 

 The steam engines usually employed in petroleum operations 

 are generally not well cared for, so that the steam used for 

 the work accomplished is often extravagant. In ordinary 

 practice the internal combustion engine, of which the natural 

 gas engine is a type, is most economical, and equals in effective- 

 ness the triple expansion condensing engine. When the natu- 

 ral gas engine is operated in the most economical manner, 

 there is a saving of nearly 50 per cent in fuel over that re- 

 quired to be consumed under boilers to operate high duty steam 

 engines, and a saving of 90 per cent over the consumption re- 

 quired for the ordinary steam engine. 



Almost the entire production of natural gas is distributed 

 to the consumers by wrought iron pipes, which vary from 1 

 inch to 20 inches in diameter. There are also in use a number 

 of miles of riveted wrought iron pipes of a diameter of 3 feet. 

 Lately many long lines have been constructed of pipe 18 and 

 20 inches in diameter. The pressure at the field end of these 

 lines is in some instances as high as 400 pounds to the square 

 inch, but it is usually from 100 to 200 pounds. Where the 

 natural well pressure is not sufficient, it is increased by large 

 compressors, before described. 



