Montana oil and mining journal., 1942-06-06

So it was that recently the Coolidge Wait
well, in the midst Of a stripper area, dropped
into a vug or crack In the top Of the Madi-
son lime and began flowing. It was the most
unlikely spot for a flowing well in all Kelvin
field. There was nothing on the surface to
even family suggest the possibility of fault
or crack. The crack must be small one. 1t
is a safe guess that wells one Or two lOca-
tiOns away viii be very small producers, un-
less acid is used to open up flow channels
to the crack
In the early days of the field, many
scOffed at the theory of GrenviIIe G. Howard
(geOlOgist who spotted the Sunburst discOv-
cry weI) who joined with the late Charley
EmmOns in the belief that there were two
faults or lines Of fracture crossing the field
from northwest to southeast. Those who
scOffed, today face the fact that 80 percent
of the production of the field has come from
pools located along these alleged faults. They
truly are not faults, with displacement such
as marks the BALCONIES fault of the Mid
continent. They are mere breaks In the Iime
severe enough 50 that there is some evidence
Of them on the rimrOck surrounding the field
on the west and some surface shOwings
which EmmOns and Howard interpreted as
evidence of disturbance.
In the light of 20 years of production his
tory, it is pretty certain that whether or
not the condition can be called a fault.
there is SOMETHING that caused the Madi-
son lime to be fractured along a trend cor
responding to that mapped by these pioneer
biologists.
This leads TO the further conclusion: If
those are NOT faults (that is, if they are
merely lime fractures without dispIacement)
then what might we have If we had true
FAULT in Kelvin field?
Everyone knows that Cat Creek field owes
its S23,OOO,OOO worth of production to a series
of small faults which bisect the sharp anti
cline. The accumulation was against these
faults without the fauIting there is grave
doubt whether there would have been an
oil field in the Cat Creek sands. Likewise,
Dry Greek field is known to owe its exist
ence to the presence Of sharp minor fauIting.
Operators have for many years been look
ing and hoping for a major fault In north
ern Montana, similar TO the BALCONIES or
other famous faults of the Aidcontinent
Texas and California. These faults invariably
give some Of the worlds greatest fields
Where the mountain building forces are
great enough to break the crust of the earth,
nting one side of the cracked portion up
higher than the other side, there is enough
cracking and breaking 20 make plenty of
flow channels in the hard IimestOnes, suf-
ficient to allow great quantities Of oil to
migrate up from below. In this process the
oil mounts ahead Of the water In the Kelvin
field the water table averages about 800 TO
400 feet higher than the top of the Madison
lime. So the water from below win carry
the oil only slightly higher than the top Of
the lime. There Is no water in the Sunburst
sand, some 600 feet higher than the top
Of the lime.
If anyone can find a major crack in the
lime-One big enough to be dignified with
the name "faults-then is 1t not reasonable
to believe that major production may be
found? That is why we are carefully watch
ing West Kelvin where the 'Rimrock fault
has been slowly worked out One company
has spent upward Of $4,000 in prospecting
along this fault line, starting up in the rim
rock where the Colorado shaIe is sharply
Tilted up above the Eagle sandstone, whereas
The normal position Of the Eagle sand is
ABOVE the Colorado shaIe.
~BiIP' Cassidy, drilling west of the town
# Kelvin, found the KOOtenai section en-
ireIy missing in one place. His well checked