STATE GEOLOGIST. 123 
five miles north of Sugar Grove, showed a rock pressure of 400 pounds, 
and one on section 2 of Laurel township, Hocking county, drilled in De- 
cember, 1901, recorded 700 pounds and nine months later 650 pounds per 
square inch. These variations indicate that the field does not consist of 
one vast reservoir, but of several small disconnected areas. These are 
separated either by the sandstone disappearing or more probably by the 
rock becoming so compact in places that it cannot act as a reservoir for 
the gas. : 
The open flow of the wells has varied greatly. Thus wells early 
drilled in the vicinity of Lancaster have ranged from almost nothing to 
12,000,000 cubic feet per day. Among the largest reported are the follow- 
ing: One in Laurel township, Hocking county, 9,500,000 cubic feet ; 
one on the Hummel tract in Berne township, Fairfield county, 10,000,000 
cubic feet; the Mithoff well in Lancaster, 12,000,000 cubic feet. These 
figures, of course, refer to the initial open flow. 
As has already been stated the initial closed pressure in the Homer 
field ranged from 700 to 800 pounds per square inch, and the open from 
1,000,000 or less to more than 11,000,000 cubic feet in 24 hours. Data 
concerning the wells in the Newark and Thurston fields have already 
been given, and it is seen that the initial closed or rock pressure of the 
entire central Ohio fields has ranged from 700 to 800 pounds per square 
inch, and that the largest well had an open flow approximating 12,000,000 
cubic feet per day. A number of experiments have been made by tor- 
- pedoing the wells, but the results have not been satisfactory. 
Life of Wells.—This depends on several factors; such as nature of 
gas rock, closed pressure, initial flow, proximity of other wells, rapidity 
with which gas is used, care taken of wells, presence or absence of salt 
water in the gas rock, etc. A small number of wells drilled ten years 
ago are still producing, but such records are unusual. The short life of 
the Thurston field has already been noted. The Homer field is too young 
to have demonstrated its lasting qualities. The following records in the 
Sugar Grove field show the decline in rock pressure and open flow of the 
wells in that territory. These are wells that have been in almost con- 
tinuous use. Of course where the wells are closed in during a large part 
of the year the decrease is much slower than the records previously given 
indicate. This point is well illustrated in the wells north of Lancaster, 
which were drilled about ten years ago, but still have a closed pressure 
of from 500 to 600 pounds per square inch. As has already been stated 
the company is holding them in reserve until the wells in other parts of the 
field are inadequate to meet the demands. The table shows very clearly 
the brief life of the wells. Since the rock pressure is decreasing it follows 
that wells drilled hereafter will be exhausted even more rapidly than those 
given below. 
