Q66 F. H. KAY OIL FIELDS OF ILLINOIS 



sand has \)ven fouiid at the hase of the Niagaran. Many of tlie wells 

 drilled outside of the present producing field harve developed small quan- 

 tities of oil at the contact of the N^iagaran with the Maquoketa, but in the 

 alisence of a proper reservoir no other commercial accumulations have 

 been discovered. Practical exploration demands that all the domes in the 

 western part of the State be located and tested in the hope that the com- 

 bination of favorable structure w^ith porous beds may somewhere be dis- 

 closed. 



Context of Oil pee Acre 



Eecent careful planimeter measurements show that Illinois has at pres- 

 ent approximately 230 square miles of producing oil territory. Up to the 

 end of 1916 it has produced about 1.830 barrels of oil per acre. 



It is difficult to secure accurate fi5>ures concerning the actual produc- 

 tion from a given sand. In general, however, despite the fact that the 

 Illinois sands are extremely variable, some of them attaining a thickness 

 of more than 100 feet- in places, the producing part is generally but a 

 small per cent of its total thickness. The different lenses of the Eobinson 

 sand in Crawford County average about 25 feet in thickness, whereas the 

 ^^pay^^ sand and averages only about 7 feet. In two of the pools the sand 

 ranges from 25 to 40 feet and is saturated with oil throughout, but this 

 condition is exceptional. 



The following fig;ures are furnished through the kindness of the Ohio 

 Oil Company. They represent the total production per acre to January 

 1, 1917, of typical farms underlain by the different producing sands of 

 Illinois : 



Total Pr-oduction per Acre for typical Areas, Illinois Sands 



Sand Depth Period, years Barrels 



Casey 350 10 5,309.98 



Casey 350 10 2,919.37 



Robinson 900^ 9 719.14 



Bridgeport 800-1,150 9 8,390.49 



Buchanan 1,150-1,350 10 36,233.98 



Kirkwood 1,350-1,650 9 2,546.22 



McClosky 1,750-2,000 S 15,672.80 



Many farms in the Lawrence County field produce from the four last- 

 mentioned sands, and at the same rate would have produced to date more 

 than 60,000 barrels per acre, a figure that becomes especially interesting 

 in view of the fact that the field will be active for many years. 



2 Average thickness, 7 feet. 



