Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1938-03-12

to rather formidable load on the
producers when industry in general again
becomes active.
"a RESPECTS for future oil discoy-
cries approximating in volume those
of the past have been appreciably
narrowed by reason of the fact that all
the oil-bearing horizons of the country
have now been subjected to more or less
intensive scientific examination. The
relatively new geophysical methods of
prospecting, and the more general appli-
cation of geological principles to the
search for oil, are still inconclusive on
the negative SIDE But it is generally
agreed that capable scientific examination
reduces the prospects for any subsequent
discovery in a field showing MO favor
able indications by an average Of perhaps
755, depending upon how responsive
the particular strata may be to geological
reconnaissance.
At the beginning of this century, 500
of the new oil discoveries were made
by random drilling and obvious evidence,
with only 1919 by scientific methods.
At the quarter-century mark, new discov-
cries by the dominant empirical method
had shrunk to 57.5%, while scientific
methods accounted for 425%. In the
1931-35 period, only 1870 of the new
discoveries were by the empirical meth
DDS. against $50 by scientific methods
and 2.4% from deeper drilling. These
pronounced contra trends demonstrate
the superiority of scientific prospecting.
And the intensive application of these
methods TO all the potential oil-bearing
horizons of the country, over a period
of 10 or is years, has materially reduced
the possibility of further discoveries COM
parable with those Of the past.
A rather extraordinary increase in the
90 nF d4snnunFfnc
ing the 1926-3O period, concurrent with
the more general application of scientific
prospecting methods, also has implica-
tions that should not be neglected Aver
age annual discoveries by five-year periods
showed an orderly increase from around
800 million barrels at the beginning of
this century, to 875 million in the 1921
25 period In the next five-year period
(when empirical methods of discovery
showed their greatest decline from 57.5
to 177% of the totaD the average an
nual discoveries scored an extraordinary
increase to the all-time high of 2,165
million barrels. And the subsequent pre-
cipitate decline to 725 million barrels
in the next five-year period suggests the
possibility that the great discoveries of
the 1860 period, coincident with the
preponderance of the more precise scien-
tific finding methods, may have brought
in the last of our large-scale oil reserves.
1t is thus apparent that there is al
ready a deficit in new discoveries, in
line with the conclusions previously ad-
vanced; and that the proximate status
quo in total reserves over the past sew
eral years has been maintained largely
bv marginal extensions of already known
fields.
There was a sharp rebound in ad-
ditions to the reserves in 1887, though
AZ so ,,.sd av, he
mates, which suggests the American
Petroleum Institute may be leaning to
the optimistic in it's Interpretation of the
results. The APP estimates the addi-
tions at 2,444 million barrels, against
1.S49 million as estimated by The Oil and
Gas Journal. AS previously noted, the
average annual discoveries in the 1881
35 period amounted to 725 million bar
rels, and the peak 5-year average annual
was 2.165 million in the 1926-3O period
The 1887 results involved heavy drill
ling operations. an increase of 500 over
the number of wells in 1885, and the
second largest of record Substantially
the bulk of these new additions to the
reserves continue to be marginal extern
sions of presently known fields. There
were no important new fields brought in.
If rate of ~ billion barrel addi-
tons to the reserves can be maintained,
the theoretical peak production will be
in 1850, and the ultimate reserves will
be four times the present reserve in
Guiding supplementary recoveries from
presently known fields with the higher
prices anticipated at peak production
An addition of IL billion barrels per
annum about meets the conditions in
the example given previously, where the
existing reserve is doubled and the
theoretical peak falls in 1913.