The Daily Ardmoreite. [volume] (Ardmore, Okla.) 1893-current, 1922-08-14
INTERESTING FACTS AND FIGURES
RELATIVE TO SPACING OF WELLS


furnishing a very interesting topic in
the ranks OF the local fraternity, and
is vitality affecting method of develop
ment in the fields of Carter county, in
asmuch as many are favoring one well
10 each 10 acres. whereas others be-
lieve that more wells 10 tract of this
size should be drilled. The economical
aspect is the outstanding feature. c.
w. Tomlinson, Ardmore representative
of the ]. B. Schermerhorn interests. is
an advocate of drilling more than one
we'll to each 10 acres and has made a
very intensive and comprehensive study
Of the matter 10 substantiate his argu-
ment, which appears in full as follows:
Bullein No. 1874 of the Bureau Of
Mines, by Carl IL. Beal and j. S. Lewis,
Is entitled Some Principles Governing
the Production of Oil Wells" 1t con-
tains a careful study of the production
records of the Bartlesville field and Of
the Glenn Pool, extending in each case
ever a nine-year period. a very careful
study is made Of the effect on produc-
ton and on ultimate profit Of different
spacing of wells.
Bartlesville Spacing.
A large number OF properties in the
Bartlesville field were drilled with an
average of three to four wells to 10
acres, and a large number Of other
properties in the same field We're drilled
with an average of about half that num-
Der OF wells. The properties in the
oh, Nf oil
acre from so per cent to 100 per cent
greater than is true for the group Of
properties in which the wells were
more widely spaced. Correspondingly,
the net income per acre from the close
ly spaced properties is shown to have
been double the net income from the
widely spaced properties.
Bureau Of Mines Data.
I. Z. Swigart and f. Y. Schwarzen-
bek, also of the Bureau of Mines, in
their bulletin on Petroleum Engineer
ing in the Hewitt Oil Field Oklahoma"
reached the conclusion (page 39) that
the recovery from 10 acres is almost
two times greater than drained by four
wells than when drained by one well, T."
and that (page 34) "a wells TO 10 acres
is more profitable than one well TO 10
acres for the top Hewitt sands, provid-
ed the wells average over 70 barrels
per day for the first month. They
reached the conclusion that one well
to five acres would be approximately
ideal spacing for greatest profit.
Both of these studies by the Bureau
Of Mines. from widely separated fields,
give approximately the following re-
suits: The second we'll on a 1O-acre
tract adds from 40 per cent to 60 per
cent to the ultimate total production
Of that tract; the third and fourth wells
on the same tract yield together a fur
ther addition OF from % per cent TO 40
Per cent OF the production from a single
we'll
Opposing Argument.
A chief argument cited by those who
favor wide spacing is this: In several
instances OF properties whose early
drilling has been widely spaced inter.
mediate locations have been drilled lat
er after the production OF the property
had dropped to a low figure These in
termediate wells have seldom increased
the total production of the property suf.
f!ciently to be profitable. The 9.year
results of the Bartlesvile field seem
10 be sufficient answer 10 this conten-
ton. The failure of these later inter
mediate wells is readily explained by
the reduced pressure then existent in
the sand. II the same hole had been
drilled when its neighbors We're drilled,
1t doubtless would have recovered the
oil from the sand in its vicinity much
more effectively. Recovery is certainly
more complete under high.pressure con.
ditions than with low pressure. It
seems rational to believe also that in
any ordinary sand the effectiveness OF
recovery decreases with increasing dis.
tance from q well. In the case OF
q cavernous limestone with heavy arte-
sian water pressure below the oil, the
oil content OF cavities a thousand feet
from the well may be drained as fully
as from the openings Immediately ad-
joining the well. But this can hardly
be true Of q sand. undess Il be remark
ably coarse. Where one well is drilled
Q 10 acres the corners OF the l0-acre
lots are 4G7 feet from any well
More Wells-MOre Oil.
To state the case simply. the more
wells drilled on a given tract. which is
producing from ordinary sands. the
greater the oil recovery from that tract:
hut each succeeding well adds a smaller
Increment 10 the total production than
its predecessor in the series. On 10
acre tract, the second well adds about
80 per cent; the third well about % per
cent. and the fourth well about 10 per