Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1937-10-02

Geophysics VS.. Doodlebugs

the operator stays within proven con-
tours. If the operator would choose
corner of his lease and drive of golf ball
as far as possible in on his lease, drill
ling in the spot where the ball comes TO
rest, he will have just as good results as
with the doodle bug.
But il does not end there. When the
bug" hits it right in a proven oil field,
THE operator is tempted to follow it out
onto the plains. And there is where the
bug comes to certain disaster. No oil
field has been brought in within the con-
fines of Montana with a dOOdIebug as
a guide. To show the accuracy with
whicIJ they work, a doodle bugger an
nOunced that a well located northwest
of the RimrOck pool, near Kelvin, would
be a 0O-barreI well That was the first
time anyone had been able to put him
'On the spot" by getting his prognOsti-
cation BEFORE the completion of the
well. These ''bugs" always remember
their prophecies AFTER the well has
come in. In this case, he had no escape
and he had lot of people believing in
him. The well was a dry hole. Then
some other operators went a mile be-
yOnd the dry hole and brought in a good
weil-proving that the bug, knew
nothing more about it than did the tramp
who happened by the well Just at meal
time
Of geOphisics, as a rule. They expIain
their instruments" in terms of geophysics.
Some of them talk of the "magnetic
principle" referring to magnetometers.
Others tell of the radio principle" which
they know is applied to amplify vibra-
lions set up by seismic disturbances. All
of them point to the record of geophysics
in finding oil fields, in other states,
where no surface evidence of structure
is to be found.
1T is true that geophysics offer the
first look into the ground" that has
been provided to scientists. But geo.
physical instruments DO NOT LOCATE
OIL. All they do is to reflect structural
conditions. In other words, vibrations
can be reflected off hard surface, like
an echo. A man standing close to a cliff
shouts and the echo will come back to him
quickly. Another man standing a long
distance away shouts and there is a great
er elapsed time before he hears his own
voice echoed back. IL the first man knew
the exact distance to the cliff and meas
ured the time OF the echo, he could tell
the distance the second man was standing
from the cliff, If he had the exact meas
ure of the time required for the sound TO
return to the second man.
With this hOmedy principle in mind,
il is apparent that if the speed of vi
bration through the earth is known, it
is possible TO measure the distance from
the surface of the ground to a competent
formation such as the massive Madison
limestone. Where the Madison lime is
arched up in an anticline, the echo
comes back much more quickly than from
spots where the lime is in normal hOFi-
zontal position. Thus structure can be
determined. These vibrations travel at
the rate of 5000 to 5000 feet per second,
so it requires very precise instruments to
measure the elapsed time 1t requires the
drilling of shot holes and the firing Of
charges Of dynamite; it requires deli
cate instruments which viii record the
slightest of vibrations; it requires even
more precise instruments to magnify,
THESE vibrations so that they can be trac-
ed on a chart, not by anything so clum-
sy as a needle but tiny ray of wavering
light which records its travel on photo
graphic sheet.
No doodle bug artist can successfully
represent that he fuses geOphysical prin-
ciples." It is true that the doodle bug
is a mysterious thing. So is a planchette.