Hewitt Oil Field 215 
as a datum plane on which to draw subsurface contours. Four east-west 
cross-sections, three north-south sections and two northeast-southwest 
sections were drawn. In addition to these cross-sections the logs of all 
producing wells were plotted on individual graphic log forms, thus 
making sections in any direction available for purpose of correlation 
and study. 
From these cross-sections and plotted logs the accompanying sub- 
surface map was made (Fig. 1). Correlation lines were drawn on the 
top of the producing sands and also on the water sands above the oil 
sands and thru sands carrying only slight shows of oil and gas. These 
correlation lines on the water sands help to check the correlation of 
the sands, although the water sands cannot be depended upon entirely 
because of their lenticular nature. 
These correlation lines show that the oil sands have a considerable 
degree of regularity, although there are some irregularities due to local 
thickening and thinning of the sands and aiso to inaccurate logs. The 
sands in the Hewitt field are much more regular than in the Healdton 
field but not as regular as in the fields of the northern part of Oklahoma. 
The structure of the Hewitt field as shown by the accompanying 
subsurface map (Fig. 1) is an elongated dome with the long axis ex- 
tending north and south, about 10 degrees west of north. The top of 
the dome is flat, covering about one-quarter section and dipping off 
steeply to the west, southwest and south. Since the completion of the 
accompanying map further drilling, extending the field north, shows 
that the Hewitt anticline has as minor structural features two domes 
connected by a slight saddle. 
The crest of the main Hewitt dome, or the dome further south, is 
in the northwest quarter of section 22, Township 4 South, Range 2 
West. From the apex the Hewitt sands dip steeply to the west, south- 
west and south. The dips to the east and north are not nearly so 
steep as in the other directions. However, the east and north sides of 
the field have not been fully limited by dry holes so the amount of dip 
has not been determined. The sands dip north to about the west quarter 
of section 15, Township 4 South, Range 2 West, where they commence 
to rise to the second dome located probably in the northwest quarter of 
section 15, Township 4 South, Range 2 West. 
The principal differences between the two domes of the anticline 
is that the north dome is higher structurally and yields strong gas wells 
whereas the south dome is lower and has never produced any dry gas 
from the Hewitt sand. 
In addition to the two minor domes on the main anticline there 
are indications of the presence of two faults. Along the north line of 
section 22-4S-2W wells are producing at considerably different depths. 
Either the sands dip steeply to the north forming a very sharp syncline 
between the two domes or else the Hewitt sand zone is faulted. The 
failure to find sands at depths where the Hewitt sand should occur in 
offset wells strongly suggests a fault with the upthrow side to the 
south. On the north side of the north line of section 22 in section 15 
the Hewitt sand not only is found about 300 feet deeper than in offset 
wells to the south, but the sand is not as productive as in the wells 
