Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1937-02-13
IMPORTANT OIL
Confined from Page One

tural arrangement which is consid-
cred favorable. There can be no
doubt that either a fault or a steep
monoclinal fold exists in about the
position shown on the map, for al
! titudes determined at definite hori-
IONS on each side show a distinct
lack OF continuity OF structure. The
total effect Is to produce a fold
with a closure of more than 200
! feet. Previous drilling on small
folds occurring in narrow strips be-
tween faults of the north-south sys-
tenn in this region has not given
favorable results. The several wells
drilled in Sec. 4-3S-25E. and one
each in Sec 81 and Sec. 34-2S-25E
were all failures. However, a con-
sideration of the structural rela-
tions shows that none Of these wells
were drilled in reasonably favorable
locations, and therefore the close
proximity of several dry holes to
the fold does not condemn it.
Well Locations
1T is believed that test well
should be located in the area north
west of the Fromberg fault and
northeast of the inferred fault in
one of the following tracts; the
NEA Sec 23-2S-25E, the NV u
NWA Sec. 24-2S-25E; the Sh Sec.
13-2S-25E Except the SEA SEX
or the NWA NV 1S-2S-26E. OF
these tracts, the first is probably
the most favorable. because of it's
nearness to both faults. A well
about 1920 feet deep would test
the Madison limestone horizon of
the Soap Greek field.
Three More DOmes
Three dOmes of small area and
closure were also mapped The
best of these lies in Sec. 33-1S-27E,
and Sec. 4-zS-z7E This dome is the
highest point of an eastward |
antIciinai flexure, on which |
the other small domes are also To-
Gated. The upper part Of this dome
has a circular outline and clos
ure of not more than $50 feet. The
favorable features Of this dome are
that although its area is relatively |
small, dips as high as II degrees
are known on the northeast and the
lip into the syndicate to the south
reaches 3 degrees. Furthermore, the
distance to the Outcrops of the re-
IerVoir rocks is so great that the
lrtesian circulation should not be
rigourous enough to flush out the
ill that might have accumulated.
he unfavordDle features are that
f the Fromberg fault zone is an eff
eetiVe barrier to artesian circula-
ion, as it is believed to be, con-
of artesian flow in the
leighborhood might be expected to
esult, and this would offset the eff
ect of the distance from the noun
aims. In the light of the last con-
liberation and the small acreage
hat could be expected to be produc-
i've, this dome seems to offer less
nducement to the prospector than
light of the folds already describ-
d.
Two Small DOmes
The other two domes, which lie
n the same anticlinal axis with
avorable and are not shown on the
zap. They are in Sec. 32-1S-27E,
nd Sec. 35-1S-26E. The one in Sec.
is the larger of the two and is
aulted. A test we'll that is being
rilled on the west or down-drop-
ed side of the fault will probably
ross it at a depth of about 5000
set, or below most or ell of the
ossible ou-bearing beds. This test
therefore, may not be entirely con-
Iusive in its findings.
Although nearly a score of test
oles have been drilled in the area
in 1929, very few if any of them
ave been located in the most favor
BILE places for testing the oil pos