The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1920-08-04
OF
OIL HEAVY LOSS
$27,000,000 a Year Lost in Mid.
Continent Field Alone.
IT ESCAPES AS GASOLINE

II ESCAPES AS GASOLINE
From Two. Thirds to Four-Fifths OF
the Less Could Be Saved by Protect
ing the Oil From the Air, Says Pc.
troleum Engineer in Report to the
| Government Bureau of Mines,
Problem Taken Up at Experiment
Stations.
In a report sent to the United States
bureau of mines, ]. H. Virgins, as
sistant petroleum engineer, says that
| the evaporation of crude oil causes
one of the largest single losses to
which the oil is subjected after it is
taken from the ground. The few days
which crude oil is stored on the lease
| before being taken by the pipe line
| causes an aggregate loss per year
from evaporation estimated at 1922
100000 gallons of gasoline in the mid
continent field alone. This has value,
at % cents per gallon, Of $26,8SO,OOO
and represents about 8 per cent of the
total gasoline produced in the United
States from all fields and all sources.
This problem is now being taken up
at the Bartlesville experimental sta
ton and at the San Francisco office
of the bureau of mines. Mr.. Virgins
in preparing his report covered only
the mid-continent field, whose output
represents more than one half the
United States production. Some of
the important features Of his report
are as follows:
Features Of Report
"The rate at which oil of given
quality and under given temperature
conditions will evaporate depends
chiefly on the way it is handled. The
ordinary method is to pump the oil
from the well, force 1t through a pipe
line gathering system, and then into a
tank by means of overshot connec-
tons. In this tank, called flow tank,
any free water is separated by grav-
ity, then the oil Is led by another pipe
to the lease storage tank. The latter
is also filed by overshOt connections
which permit the oil to fall 8 to 10
feet and splash into the tank, causing
spray. After standing In this tank
perhaps two to ten days the oil Is
run by the pipeline company by
means of pumps and pipe lines to the
large steel storage tanks. These have
bottom connections and nearly gas
tight roofs. The oil is run from here
TO large tank farms or directly to the
refinery by pipe lines or tank cars.
Each of these steps constitutes a
different class as regards rate of evap.
grafton. These classes may be divided
as follows: (1) Filling tank by over
shot connection; (2) filling a tank
by bottom connections; (3) storage in
small unprotected tanks on the lease;
az storage in small tanks on the
lease which have some protection such
as shading or an alright jacket, and
(5) storage in $1,000 or $1,000 barre
|" steel tanks which have so-called gas
tight roofs.
"Filing the tank by overshot cor
nections Is the cause of the most rap
i'd loss. The amount Of this loss de
ponds on several variables, such as
the height from Which the oil falls
the velocity and size of the stream
and the size Of the tank as compared
with the time required to fill it. Sew
eral tests were made which show that
the loss in "a hours from such condi
tons ranges from to 2Ia per cent of
the original volume in the summer
time Evaporation during the storage
on the lease in unprotected tanks
shows a high rate. Data obtained
from some of the largest independent
producing companies in the mid-conti-
nent field show that the average period
of storage is five days. in that time
oil stored in a 250-barrel steel tank,
unprotected, will lose % to 81 per
cent by volume; oil stored in 500-bar-
rel steel unprotected tanks, about 2
per cent; a 1900 barrel wooden tank,
which is protected by a house that
acts both as a shade and windbreak,
will lose about IL per cent. The above
figures are for summer conditions but
tests covering this phase Of the sub
ject were run for summer, autumn and
winter.
Conclusions Drawn.
data were kept on semi-monthly
losses in eighty $1,000 and 37,0O0bar-
rel steel tanks from which the average
evaporation loss was computed. Re-
suits show that oil stored in such a
tank will In the first year lose 3 per
cent of its original volume, and In the
second year FL per cent, giving loss
for the first two years Of 81 per cent !
In considering evaporation losses Of
crude oil, one must remember that the
portion that escapes is gasoline, and
moreover is the lighter. most valuable
part of the gasoline. This light gaso-
line, If saved, would command the
highest price. The value Of the frac-
ton lost is more than three times the |
value of an equal volume of crude. |