Montana oil and mining journal., 1942-04-11

commercial The first commercial well drilled
the Campbell discovery well, found its oil
at the TOP of the Madison lime and there
fore the TOP of the Madison lime has since
been the Objective-the stopping pOint-Of
every other well drilled.
The Dry Forks well was drilled OFF
STRUCTURE-in about as unfavOrabIe a
spot as can be found in the Sweetgrass
Arch In spite of this structural handicap,
it had oil in the DevOnian.
1t follows that if structure or oil trap
can be found in this region, it may contain
oil in not only commercial quantities but in
large quantities.
Is Midway the place?
E. Byers Emrick, disc0verer of POndera
and Bannatyne oil fields, discovered Midway
and so named it because of its relative pO-
sition between these two oil pools. He found
surface evidence of a fold but it was diff
cult to locate the "high," owing to glacial
drift. Ralph Arnold cOncurred In his geOI-
Ogy and Montana Pacific Oil Co. (Organized
by Ralph ArnOId) drilled a wen on the
west end of the fold. 1t was dry. However,
such companies as Midwest Refining Co..
Ohio Oil Co., Texas Pacific Coal g. OIL Co.
and others purchased leases on the structure,
their geOlOgists finding evidence Of structural
conditions
In fact, Midwest Refining Co. (Standard
of Indiana) was not convinced by the dry
hole and employed firm of geOphysists to
make a survey of Midway district. That was
the first time geophysicaI methods were
used in Montana. The discovery of the ''high"
a considerable distance EAST Of the Mon
tana Pacific well caused Midwest to attempt
to lease up the structure-hOwever, without
success. The Midwest tried TO use a COM
munity lease and the landowners refused
to lease. However, Midwest did succeed in
securing several 10-year commercial leases
and these the Midwest held for the full
term of 10 years. Thus StandOInd had faith
enough to invest $40 per acre in part Of
Midway.
After the Midwest leases expired, Emrick
interested HeiIand Research Co. of Denver,
to make a geOphysical survey Of the struc-
ture Using seismOgraph, this firm found a
structural condition, confirming the work
of the pioneer geOphysicists.
Thus Midway Is the only structure In the
SweetgraSs Arch which has been established
as 4 structure or trap capable Of holding
oil by TWO geOphysical methods, plus geOI-
Ogy. The presence Of a vast dome is proven
by the logs Of wells drilled north, northeast
south and west and the regional dip Of the
strata is to the east-tO the eastern edge of
the Sweetgrass Arch. Midway Is said to be
ON the axis of the Arch at a point where
the influence Of the Belt mountains caused
the axis to swing southwest off its normal
course of northwest to southeast.
The most successful geOIOgists who have
visited the Sweetgrass Arch agree today that
the DevOnian carries oil. The presence of
oil in the DevOnian in Bears Den, in the
Sweetgrass Hills; in the Frazer-Rice deep
test on the northeast edge of Kelvin field,
and in the Dry Forks well, is pretty good
evidence that the DevOnian is a petrOlifer-
Ous horizon. Add to that the known De-
VOnian oil in northern Alberta, and there is
no possibility Of anyone cOntesting the
statement that the DevOnian where present
S an oil-bearing formation.
The advantage Of geOphysicaI survey over