Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1940-06-29

X URRENT NEWS regarding oil devel-
! opment in Illinois is always inter
- esting to us because we cannot help
but feel, that these accounts are the
outlines of future history of the Montana
ell industry.
Illinois is going through a period of
development that is coming in Montana,
we believe, and the day is not far dis
tant wher Illinois history will be re-
peating in Montana.
This is brought to mind currently by
the development of Ordovcian produc-
ton in Centralia field. This may again
completely revise the figures on Illinois
reserves and may force Illinois produc-
ton up to a half million barrels per day.
Illinois production figures had to be re-
vised as a result of the development of
Devonian production, and now comes the
discovery in the lower horizon
In Kevin-Sunburst field the Ordovician
is found at approximately 5000 feet. 1t
would be much shallower in many places
in the Sweetgrass Arch, notably at Ban
natyne where 1000 feet would test all
known horizons capable of producing oil.
There are scores of structures where the
Devonian can be reached under 5000
feet-which is shallow drilling in this
day.
The Devonian. known to contain oil,
was found at $500 feet in Kevin-Sun-
burst field, and at 5000 feet at Bears
Den structure where it also carried oil.
The Ordovician is the horizon in which
the famous Wilcox sand of the Midcon-
tinent is found. It's oil possibilities have
not even been considered here in Mon
tana, but the Illinois discovery points
out the fact that the Trenton limestone
is an important source of oil in the United
States. We were reminded by a geolO-
gist with whom we talked this week that
there is a 100-foot sand in the Ordovi-
clan in northern Montana. 1t is exposed
in the Rocky Mountains and is there
called the Flathead quartzite.
The development of deeper horizons
in Illinois was delayed for many years
by the same cry that has been heard in
Montana: that there are no SANDS in
the horizons below the Madison lime.
Illinois is getting 10,000-barrel wells
from the Devonian lines which are treat
ed with 5,000-gallon acid shots. The
LIMESTONES and not SANDS have made
Illinois a great oil producing state.
Illinois, like Montana, produced con-
siderable oil from horizons above the
big lime and then dropped out of the
picture as an important oil producing
state. The fields dropped off to strip
per production. Royalties and leases
were not IradeQ IN because none cOulu
see any possibilities in the future.
With the coming of the science of
acidization and deeper drilling, combined
with geophysical prospecting, someone
conceived the idea that old fields in
Illinois offered greater certainty for deep
production than places where there had
been no drilling The theory sounded
sc simple that many dismissed it as a
foolish waste of money, but deeper drill
ling brought new production and acidi-
cation brought large wells and so in five
years time Illinois has become the No.
1 problem child" on the oil industry,
with a recent peak production of 47S,4s1
barrels per day.
IwN HE lime production in Illinois
comes from about the same drill
ling depths as at Kelvin, most of
the production coming from around 1000
feet, average Kelvin production aver
ages less than 1000 feet. Then came
the inevitable dry hole in the lime and
the drillers kept on going. The result
was that they penetrated the Devonian
and brought in a well in centralia field