Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1936-05-09
OUR NEXT OIL FIELD?
The Del Bonita Test AND me Dunbar FoId

NY o MOntanan can afford to overlook
the significance and importance of
developments at the Del Bonita
well ON the northwest rim of the Sweet
grass Arch.
This well happens to be short distance
north of the MOntana-AIberta boundary.
Its location in Canada means nothing.
The Almighty Hand which placed the oil
in the folds along the east face of the
Rocky Mountains was no reSpector OF
man-chOsen geographical boundaries. The
boundary line means nothing, geolOgicalIy.
The Del Bonita well might just as well
be in Montana in Alberta, so far as
it goes to determine the oil and gas pos
sibiIities of the west TANKS of the Sweet
grass Arch.
Significance of the Del Bonita wen
applies to similar folds west of Cut Bank
oil field. The Del Bonita well proves
that beyond the possibility of a doubt,
deep folds along the face of the Rocky
Mountains win produce oil and gas. As
prospecting proceeds westward, rock pres
sure Will likely increase. Some big wells,
unprecedented In Montana oil history,
may mark the development of the area
WEST of the Sweetgrass Arch.
The Del Bonita well is not a large oil
producer it stands. 1t may develop
into a large producer before it is COM
pleted. But without large production in
particular AON<4&AOMs IACEG ~ no QuCS@
ton but that it proves the presence OF oil
in the folds west of the Sweetgrass Arch.
In other words, wherever the oil pros
pectOr can find a reversal or a fIattening
of the beds as they climb up onto the
Arch, he may safely expect TO find oil
in either the Sunburst sand, the Cut
Bank sand, the ElIis-NIadison contact or
in a ''break" in the lime.
The Del Bonita well had oil in the
SunbuFst sand: how much, none knows.
It was drilled with rotary tools and the
showing wan passed by for the reason
that Sunburst sand production, as a rule
ds Of not great significance in the Cut
Bank area. The possibilities of this Sum
burst sand showing were not appre-
became a 1,O0O-barreI well.
1t viii be recalled that the Lander
had a showing of oil in the Sunburst
sand but it was cased off and drilling
continued, as usual, to the Cut Bank
sand. The well was hardly commercial
in the lower horizon, so the owners shot
away the casing and the surrounding
layer of cement i'm an effort to get a fe
more barrels of oil to possibly make the
well a small pumper. The heavy charge
of nitro glycerine was followed by a
gusher flow rated at 1900 barrels per
day. This well has actually made L.
800 barrels in "a hours, so this is not
guess nor an estimate of the initial. 1t
has been called 1,OOO-barrel well by the
owners but it consistently made more than
900 barrels per day.
This well brought to light the pos
'ibility that i'm proceeding westward down
he flanlxs Of the Sweetgrass Arch, oil
will be found in the upper sands. As
Importing evidence for this theory, oil
S found In considerable quantities i'm an
ven higher sandstone, in the base of the
colorado formation, on the EAST slope
4 the Arch.
Realization of these facts caused the
wners of the Del Bonita well, located
Orth and west of the Lander well, TO re-
ret their failure TO test the showing
the Sunburst sand before IL was mud
ed and cased off, Accordingly, they
led TO shoot this sand with perf0rator
hich fired "A calibre sIugs into the
'rmatiOn, penetrating the steel and mud
nd lodging deep I'm the sandstone. This
ethOd has never before been tried i'm
70 north Rocky Mountain region and it's