Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1941-01-04
IS THERE OIL IN THE DEVONIAN
CONTINUED from Page Onsl

was TO iDe SupplieQ 10 them some
what later from the Chattanooga
shales."
He declared that much of the
eo-ealled mississippi lime" pro-
duction in Oklahoma and Kansas
has been proved to be of older
age. THE absence of representa-
tives of the upper Shaly Mississip-
plan (Madison lime in Montana)
beds in northeastern oklahoma
leads to the belief that 1t has been
removed by erosion from that sec
ton. The late Mississippian Is the
source of much oil in Illinois and
western Indiana. The source of
the oil in these various areas may
be considered as either the early
Mississippian or late Devonian Chat
tanooga shale, or it's equivalent, or
as the shale beds in the middle
and upper Mississipian.
In urging the importance OF the
Devonian. Lilley pointed to the oil
production found in the Devonian
in the Mackenzie valley Of Canada.
He referred to the Fort Norman
oil field which is in the Rocky
Mountain uplift, as is Alberta and
Montana, and which produces from
the Devonian. Thi. field was dis
covered in 1919. The wells are on
Mackenzie river. about so miles
northwest of Fort Norman. The
discovery well was reported to nave
developed into 100-barrel pro-
Queer. Two other wells produced
about 40 barrels per day. A new
refinery is now being built by I'M
periaI to handle this crude
In the Mackenzie river area the
Devonian is expoled on the surface
and is known to be highly petroli-
ferrous with frequent oil seepages.
Presence of oil seepages caused the
drilling at Fort Norman, rather
than structural conditions.
G. S. Hume in "Oil and Gas in
Western Geology Series No. of
Canada Department of Mines, re-
lates the history of this develop
ment and tells of the Devonian for
nation
Northwest Company Imperial
Oh Company No. l well was drill
ed in 1920 on the east side of Mac
kenzie river at the mouth of BOs-
worth creek. This is the "discov-
cry" well in which oil estimated at
100 barrels a day was obtained at
depth of 7S3 feet The oil came
from the Fort Greek shales and
cavings caused the cessation of the
flow. In 1922 the well was deep
ened to 951 feet and flow OF 60
to 20 barrels of oil was secured.
In 1928 the well was further deep
ened to 1.025 feet and the flow of
oil increased to about 100 barrels.
II is understood the well has a
potential capacity at the present
time of about 100 barrels a day.
The we'll is now capped.
The No. 2 we'll $50 feet from
the No. 1, had a production of ITO
bbl per day.
1.-The Northwest Oil company's
No. well was drilled on seepage
of oil issuing from the Bosworth
formation. A number of other
seepages from this formation are
known east OF the Mackenzie, but
so far as the writer is aware no
seepages have been reported in this
area west of the Mackenzie. The
Bosworth formation consists Of
alternating beds of shale and sand
stone and is considered the most
favorable for oil accumulations OF
any of the Devonian formations,
since the proportion of sand in it
is much higher than in any other
Devonian horizon.
"As proved by the Northwest Com
q L. ha -
Creek formation contains oil. The
shales of this formation in many
exposures are highly bituminous.
THE brecciated limestOnes that
are tentatively placed in the Sill
urian Bear Mountain formation are
in places so highly bituminous that
a strong odor is emitted on break
ing the rock. These brecciated
limestones are. in places, quite dolo-
mitic and are sufficiently porous
to act as an oil reservoir. At other
places, however, they contain much
gypsum and it is possible the brec-
citation has resulted from the
change of anyhydrite to gypsum
1t is possible in certain localities
these rocks might be found to be
Oll-DedIIuB, DuL IN the noun ldlHH
where they are exposed no seepages
of oil from them were seen.
The basal Cretaceous beds are
largely sandstones with some shale
and as they lie in certain localities
on the Bosworth formation which
rs undoubtedly oil-bearing, they
might under favorable structural
conditions act as oil reservoirs
The basal sandstones are overlain
by fissile black shales capable
on account of their fineness, oil
acting as suitable cap rock tC
retain the oil. In certain locali
ties, however, the. Black Creta-
ceous shales rest directly on the
Devonian and as the Cretaceous Is
separated from the Deyonian by al
erosional unconformity, the Creta
eeous rests on the Bosworth forma
ton in some localities, as for ex
ample at the Ramparts of the Mac
kenzie, the Cretaceous shales rest OF
the Ramparts limestone The mos
favorable localities. therefore, fot