U.S. DEPARTMENT OF THE INTERIOR
Well logs and
core data from selected cored intervals, National Petroleum Reserve, Alaska
Nelson,
Philip H.
1
,
and
Kibler,
Joyce E.
1
This report is
preliminary and has not been reviewed for conformity with U.S. Geological
Survey editorial standards or with the North American Stratigraphic Code.
Any
use of
trade, firm, or product names
is for descriptive purposes only and does not imply endorsement by the
U.S. Government.
2001
In June, 2001, the U.S. Geological
Survey presented a core workshop, “Petroleum plays and systems in the National
Petroleum Reserve – Alaska (NPRA)”, in conjunction with the Society for
Sedimentary Geology and the American Association of Petroleum Geologists.
This
collection of plots of well logs and core measurements includes all cored
intervals presented at that workshop (Table 1).
The left-most track on the
plots includes the gamma-ray and spontaneous potential (SP) logs, which
are sensitive to lithology.
The
second track gives the depth in feet.
The third track shows the
resistivity logs, scaled in ohm-meters over two or three logarithmic cycles.
The
resistivity logs are of various types:
deep
induction (ILD), deep laterolog (LLD), shallow laterolog (LLS), laterolog
8 (LL8), spherically focused log (SFLA_A), and 16-inch normal (R16 or SN).
The fourth track includes
the neutron log, scaled in percent porosity.
The
bulk density log is scaled from 1.65 to 2.9 g/cc, so a sandstone with a
grain density of 2.65 g/cc would have a porosity matching the neutron scale.
The
porosity measurements on core samples, labeled PORCORE, are scaled to match
the neutron scale.
Porosity increases
to the left.
Where available, total
organic carbon (TOC) measurements, in weight percent, are also plotted
in this track.
Permeability measurements
on horizontal plugs (PERMCORE) are plotted in the fifth track.
Permeability,
in millidarcies over four logarithmic cycles, increases to the left.
The cored intervals (left
red bar) and the intervals over which drill stem tests were conducted (right
green bar) are shown in the sixth track.
Plots for all wells extend
only over cored intervals, except the plot for the Lisburne well, which
extends over the entire well.
The
Lisburne plot includes the sonic log and mud weight and also includes a
color bar showing the Torok Formation and the thrusted repeat sections
of the Lisburne and Etivluk Groups.
Formation intervals were taken
from Bird (1988), with a few modifications where Kemik Sandstone has been
re-interpreted as Kingak Shale (Houseknecht, 2001).
Well
locations and well test results are also given by Bird (1988).
Abbreviations
for formation tops are used on the well log plots; these abbreviations
are explained in Table 2.
Bird, K.J., 1988, Alaskan
North Slope stratigraphic nomenclature and data summary for government-drilled
wells, Chapter 15
in
Geology and exploration of the National Petroleum
Reserve in Alaska, U.S. Geological Survey Professional Paper 1399, p. 317-353.
Houseknecht, D.W., 2001, Sequence
stratigraphy and sedimentology of Beaufortian strata (Jurassic – Lower
Cretaceous) in the National Petroleum Reserve – Alaska (NPRA),
in
Houseknecht, D.W., ed., NPRA Core Workshop; Petroleum plays and systems
in the National Petroleum Reserve – Alaska, SEPM Core Workshop No. 21,
p. 57-88. |
