Petrographic survey and appraisal of reservoir quality and potential, National Petroleum Reserve, Alaska

50 Pages·1991·5.5 MB·English

by  Mowatt, Thomas C

blm library
rtment ofthe Interior
.and Management
88070040
Alaska State Office
222 West 7th, #13
Anchorage, Alaska 99513
Petrographic Survey and Appraisai of
Reservoir Quality and Potential,
—
National Petroleum Reserve Alaska
Thomas C. Mowatt and
Joseph A. Dygas
JK
870
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06
September 1991
no 36
.
c. 2
Author
Thomas C. Mowatt is a geologist forthe Bureau of Land Management. Joseph A. Dygas is a geologist and
the chief of the Branch of Lease Operations, Division of Mineral Resources for the Bureau of Land
Management Alaska State Office.
Open File Reports
OpenFile Reportsidentifytheresultsofinventoriesorotherinvestigationsthataremadeavailabletothepublic
outside the formal BLM-Alaska technical publication series. These reports can include preliminary or
incomplete data and are not published and distributed in quantity. The reports are available at BLM offices
in Alaska, the USDI Resources Library in Anchorage, various libraries ofthe Unversity of Alaska, and other
selected locations.
Copies are also available for inspection at the USDI Natural Resources Library in Washington, D.C. and at
the BLM Sen/ice Center Library in Denver.
Petrographic Survey and Appraisal of
Reservoir Quality and Potential,
—
National Petroleum Reserve Alaska
Thomas C. Mowatt and
Joseph A. Dygas
Bureau of Land Management Open File Report 36
Alaska State Office September 1991
Anchorage, Alaska 99513
.
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WALAKPA #1 TEST WELL
3060' - KINGAK. LITHARENITE. FINE SAND. 10% VISIBLE
POROSITY, OF FAIR (OR BETTER?) EFFECTIVENESS.
FAIR RESERVOIR QUALITY AS IS.
FAIR-GOOD POTENTIAL FOR IMPROVEMENT, VIA DISSOLUTION
OF LABILES (CARBONATE CEMENTS AND GRAINS; CHERT,
AND/OR OTHER LITHIC GRAINS)
SOME MINOR CLAYS (AUTHIGENIC-?--CHLORITE? IN
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SUMMARY
As part of the reservoir management, resource assessment, and
planning programs of the Bureau of Land Management in Alaska, the
oil and gas resource potential of the National Petroleum Reserve in
Alaska (NPRA) is undergoing review in light of new technical
information, as well as changing national and international
socioeconomic conditions. Emphasis in this work has been on
integration of geological, petrophysical, geophysical, and engineering
information, in order to provide a refined, more technically
substantive knowledge base for resource assessment and management.
Petrologic-mineralogic characteristics have been reinvestigated,
related to petrophysical parameters and wireline log responses, and
integrated with available engineering data, for selected key wells
within and peripheral to the NPRA. Particular attention has been
directed to diagenetic relationships, effects on reservoir quality, and
implications for untested portions of this sizable sedimentary basin.
Emphasis has been on clastic rocks, Brookian as well as pre-Brookian.
Only some 127 exploratory wells (all but one under government aegis)
NPRA
have been drilled within or adjacent to the (which is a
geographic area on the order of 37,000 square miles-about the size of
the state of Indiana). Many of these wells were only drilled to
relatively shallow depths.
In almost every well drilled to any appreciable depth in the area,
there have been noteworthy manifestations of the presence of
hydrocarbons. The results to date might well be interpreted as being
rather promising, actually, from a qualitative geological-geochemical
perspective, in terms of the potential for significant resources to be
present.
INTRODUCTION
The National Petroleum Reserve in Alaska encompasses a large
portion of western Alaska, north of the Brooks Range, as shown by
Figure 1. An appreciable portion of the NPRA is underlain by geologic
terranes favorable for occurrences of petroleum resources. This has
been recognized for many years (Gryc, 1985). The NPRA must also, of
course, be considered in the overall regional context of northern
Alaska, and contiguous offshore areas of the Beaufort Sea and the
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Figure 1. Location map. National Petroleum Reserve in Alaska
(NPRA)
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