PETEOLEUM EESOURCES — AENOLD. 279 



districts, or States. The price may vary from 10 to 15 cents a barrel 

 at the well, as at certain periods in the history of the Mexican or 

 California fields, or it may range up to $2.50 per barrel, and in ex- 

 ceptional cases much higher, when the demand is great and the sup- 

 ply limited. Price of oil largely affects the other artificial factors, 

 which may be summarized as follows: 



2. Depth of ivells and time required to drill. — Production may be 

 accelerated or retarded by the time required to drill wells. In some 

 places wells can be put down in a week or 10 days; elsewhere it may 

 take from one to two years to finish a well. In a shallow well dis- 

 trict production can be increased quickly by a vigorous drilling pro- 

 gram ; in deep well areas much time and mone}' may be necessary to 

 increase or even sustain production. 



3. Distance separating wells. — Within a certain underground 

 reservoir, the quantity of oil that ultimately can be recovered and 

 the rapidity with which it may be produced are largely dependent 

 on the distance separating the individual wells. The thicker the 

 wells the quicker the recovery of the oil and the greater the expense 

 of recovery. Wells may be spaced 25 feet apart or as near together 

 as the derricks will stand, as in the congested Spindle-top field of 

 Texas, or they may be separated by a distance of one-fourth mile or 

 mo]"e. Ownership of property often determines the spacing of the 

 wells, many small tracts under separate ownership tending toward 

 congestion of development and rapidity of recovery. Conservation 

 is best attained by single ownership of large bodies of land, so that 

 development will be determined by the principle of recovering the oil 

 at the least possible expense, that is, with the least number of wells. 



4. Condition of loell, pump, etc. — The condition of the well, pump, 

 and other physical properties involved in the winning of the oil 

 greatly influences the production. Clean wells, efficient pumps, and 

 energetic employees tend toward maximum production ; sanded up or 

 improperly perforated wells, leaky pumps, and inexperienced or 

 careless employees militate against successful operation. 



5. Discovery of new fields. — The discovery of new fields is a most 

 potent factor in oil production. The search for new fields is stimu- 

 lated by high prices; their discovery usually results in a flush yield 

 and a lowering of the price. Obviously, each new field raises the 

 normal production to be expected from any district or State, and it 

 is this factor of new territory which lends so much uncertainty to the 

 oil business. 



6. Distance from market. — The distance from market of any field 

 or group of wells often determines the rate of development and con- 

 sequent production. Those fields nearest to market or favorable 



