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Alaska Gas: Key Drivers and Issues
- The first gas production from northern Alaska will focus on the
proven, low-cost reserves at Prudhoe Bay (26 tcf).
The most likely scenario for exports of northern Alaska gas is a gas
pipeline down existing highways from Prudhoe Bay to Alberta, Canada. No
decision has yet been announced. The State of Alaska, Yukon Territory,
and most stakeholders advocate a highway route. Existing regulatory
permits and international treaties, subject to review, authorize the
highway route.
Phillips Alaska estimates that prices above $3.50/mcf at Chicago city
gate are needed for economic success. Chicago city gate prices were
approximately $8/mcf in January 2001.
Gas delivery to U.S. via gas pipeline from Prudhoe Bay is not expected
before years 2007-2010. Regulatory delays or litigation could delay it.
The gas pipeline will be sized for efficient transportation of the
known gas reserves at Prudhoe Bay. For a 4.0 billion cubic feet per day
pipeline, excess capacity would become available in year 2023 (assuming
a 2007 start up).
Cook Inlet remaining natural gas reserves (2.56 tcf) will be depleted
by year 2012. New gas sources must be located soon to supply the
majority of the State’s population which lives in the area around Cook
Inlet.
The most attractive gas province in the Bering Sea is North Aleutian
basin, which is closed by moratorium until year 2012.
LNG export models are required for future Bering Sea gas production.
Potential gas resources cannot be taken to the U.S. West Coast because
there are no LNG receiving facilities. The most likely LNG export models
deliver gas to Japan or other Asian Pacific Rim countries.
Alaska has a huge resource base of discovered and undiscovered gas
(217.91 tcf), but 88 percent of this gas is undiscovered. Expensive and
time-consuming exploration programs will be required to identify new
commercial gas fields.
Summary
Alaska contains 39.88 trillion cubic feet (tcf) of gas remaining in
developed and known undeveloped fields. Some of this gas is in fields too
small or remote to justify economic development. Of the known gas
reserves, 26.92 tcf may be considered available for export at appropriate
market prices and pending construction of new gas transportation systems.
Most of this gas is in onshore fields and mostly beneath State of Alaska
surface or submerged lands. No Federal offshore gas reserves are
considered to be readily available for export at present.
Three percent (0.92 tcf) of Alaska’s exportable gas reserves occur
within fields in the Cook Inlet basin of southern Alaska and are at
present dedicated to future LNG exports to Japan. Cook Inlet has 2.56 tcf
in total remaining gas reserves, most of which is used locally or
converted to fertilizer feedstock. At present rates of consumption, all
Cook Inlet gas reserves will be depleted by year 2012.
Ninety-seven percent (26 tcf) of Alaska’s exportable gas reserves
occur within fields in or near the Prudhoe Bay field in northern Alaska.
The Prudhoe Bay area gas reserve base totals 30.90 tcf (developed fields
and Point Thomson field, not including carbon dioxide), but some of this
gas will be consumed (current rate 0.2 tcf/yr) by future (oil and gas)
production activities at Prudhoe Bay. The stranded gas reserves at Prudhoe
Bay are presently attracting proposals for construction of a gas
transportation system that can take the natural gas to markets outside of
Alaska.
In the Mackenzie delta area of Canada (300 miles east of Prudhoe Bay),
exploration drilling from 1970 and 1989 discovered 53 oil and gas pools
about equally divided between the onshore and offshore areas. The
Mackenzie delta area contains approximately 9-12 tcf of discovered gas,
some of which may be in pools sufficiently large to justify construction
of a new gas pipeline to take the gas south to Alberta. The largest gas
field is Taglu (2.07 tcf) located onshore. All of the Mackenzie delta
discoveries are stranded at the present time, although several development
proposals are under consideration.
A total of 83 exploration wells have tested prospects in the Federal
waters offshore Alaska since 1976. Exploration results have been
disappointing, and the few significant oil and gas discoveries made in the
Arctic remain undeveloped due to high capital costs and uncertain prices.
Two offshore oil fields, Liberty and Northstar, will begin production in
2001-2003, but the associated gas will be used for lease operations. The
Burger well, located on the Chukchi shelf 360 miles west of Prudhoe Bay,
penetrated the largest gas pool found to date in the Alaska Federal
offshore. However, Burger is located in a formidable setting far from
existing infrastructure and is uneconomic to develop with current
technology and price conditions.
Most (82%) of the 190.99 tcf of undiscovered natural gas resources
forecast for Alaska and the Alaska Federal offshore occur in the Arctic.
If the undiscovered gas resources in the Mackenzie delta (53 tcf) are
added to those onshore in northern Alaska (63.5 tcf), and Federal
submerged lands on the Beaufort (32.07 tcf) and Chukchi shelves (60.11 tcf),
the Arctic regional undiscovered gas potential totals 208.68 tcf. This
volume is equal to 40% of the total U.S. undiscovered conventional gas
resource base (526 tcf). Arctic Alaska and the Mackenzie delta seem
destined to someday become major producing areas for natural gas. However,
a significant fraction of the undiscovered gas resources could occur in
small, remote accumulations that may never be profitable to develop.
Across Alaska and the Alaska offshore, unconventional sources like gas
hydrates and coal bed methane are estimated to contain up to 170,000 tcf
of natural gas in place. Most of this hypothetical natural gas resource is
contained in gas hydrates that are located far offshore in water depths
exceeding 300 m and will remain inaccessible for the foreseeable future.
However, 37 to 44 tcf of gas are estimated to occur in sub-permafrost gas
hydrates in and around the Prudhoe Bay-area developed oil fields and might
be exploited on an experimental basis once a gas transportation
infrastructure is installed.
Resource assessments in 1995 and 2000 estimated the total undiscovered
conventionally recoverable gas resource base and the fractions of that gas
resource base that could be profitable to develop. Several Alaska
provinces, onshore and offshore, were found to potentially hold economic
gas resources at landed market prices of $2.11 and $3.52/mcf (constant
$2000, equivalent to oil at $18/bbl and $30/bbl). At $2.11/mcf paid at a
variety of markets, 6.172 tcf gas might be economic to develop across
Alaska (5.14 tcf for offshore alone). At $3.52/mcf, 12.23 tcf gas might be
economic to develop (8.67 tcf for offshore alone). The undiscovered
economically recoverable gas resources (12.230 tcf) represent only 6% of
the 190.99 tcf total undiscovered conventionally recoverable gas resource
base for all of Alaska.
At high gas prices like those witnessed in the U.S. in recent months,
economic recoverability improves for most offshore Alaska provinces. At a
gas price of $6/mcf (constant $2000) delivered to a variety of markets,
the Alaska Federal offshore could contain a total of 35.78 tcf of
undiscovered economically recoverable gas. At $6.00/mcf, 20.0 tcf could be
economic to co-produce with oil resources on the Chukchi shelf and deliver
as LNG to Pacific Rim markets. Associated gas resources produced through
new offshore oil fields on the Beaufort shelf and delivered to a plantgate
at Prudhoe Bay become economic at prices of $1.00/mcf or higher, with 4.66
tcf economically recoverable at $6/mcf. If produced gas is delivered to a
hypothetical plantgate at Kivalina—the port for the Red Dog mining
operation—Hope basin could have economically recoverable gas resources
of 2.27 tcf at $6/mcf. Not all basins invite economic development. Even at
a $6.00/mcf price, most of the Bering Sea provinces remain uneconomic. Gas
prices of $10/mcf to $15/mcf would be required to support significant
economic gas development in Norton basin, St. George basin, or Navarin
basin. At $6/mcf, North Aleutian basin in southern Bering Sea offers 5.90
tcf of undiscovered, economically recoverable gas. However, North Aleutian
basin is under a moratorium forbidding oil and gas leasing, exploration,
or development until year 2012. At $6/mcf delivered to the local gas
transmission pipeline network in Cook Inlet region, the Lower Cook Inlet
(Federal waters) could have 1.24 tcf of undiscovered economically
recoverable gas. At $6/mcf delivered as LNG to Japan, the Shumagin-Kodiak
shelf and Gulf of Alaska shelf could have 1.40 tcf and 0.31 tcf,
respectively, of undiscovered economically recoverable gas.
The Prudhoe Bay-area gas reserves (26 tcf ) are the key assets that
will drive near-term strategic decisions about how to transport and market
stranded natural gas from northern Alaska. Since 1977, natural gas
recovered during oil production has been re-injected to increase oil
recovery or used as fuel for production facilities. Over 35 tcf of gas has
already been produced and re-injected or consumed at the Prudhoe Bay area
fields. In 1999, gross gas production from the North Slope oil fields was
3.15 tcf (8.63 bcfpd) of which 93 percent was re-injected.
The 5.8 billion barrels oil reserves remaining (as of late 1999) in the
Prudhoe Bay area fields (originally17 billion barrels) are now only a
little larger than the remaining gas reserves—an energy asset equivalent
to 4.6 billion barrels of oil. Northern Alaska oil production is declining
precipitously and there is some concern about when production will fall
below the minimum required to profitably operate the Trans Alaska oil
pipeline (TAPS). As the Prudhoe Bay area oil fields begin to approach
depletion, daily gas production is increasing and gas-handling capacities
may someday further constrain oil production. Expansion of gas-handling
facilities may be required to allow oil production to continue at optimum
rates, or, at least at rates sufficient for TAPS operations.
Alternatively, gas sales out of Prudhoe Bay could help avoid capital
outlays for new gas-handling equipment. Limited gas sales could begin at
any time from the Prudhoe Bay-area fields without affecting recovery of
the remaining 5.8 billion barrels of oil reserves. Major gas sales could
begin after year 2015 with no harm to ultimate oil recoveries, and the
impacts of earlier gas sales could possibly be mitigated through measures
like increased waterflood and carbon dioxide re-injection (Meyers, 2000).
At present, three concepts are in the forefront for commercializing the
stranded gas resources in northern Alaska and Mackenzie delta:
- A New Pipeline Connecting to the Canadian gas pipeline network.
Build conventional or high-pressure gas pipelines to carry the gas from
Prudhoe Bay and Mackenzie delta to northern Alberta or British Columbia,
where the new pipeline would join the Canadian pipeline network and
supplement ongoing transmission gas exports to the U.S. Pipeline
capacities of 2.5 bcfpd (0.9 tcf/yr) or 4.0 bcfpd (1.46 tcf/yr)
delivered to the western Canada pipeline network typify most proposals.
- Liquefied natural gas (LNG) to Asian Pacific Rim.
Build a
conventional or high-pressure gas pipeline that carries the gas from
Prudhoe Bay-area fields to a port in southern Alaska, where the gas is
chilled to liquefied natural gas (LNG) and loaded on special LNG tankers
for transport to the Asian Pacific Rim or perhaps the U.S. West Coast
via return pipeline from hypothetical a port in western Mexico. System
throughput for current proposals ranges from 1.5 bcfpd (0.5 tcf/yr) to
2.5 bcfpd (0.9 tcf/yr).
- Gas to liquids (GTL) and tankers to U.S. West Coast.
Build a
new facility in the Prudhoe Bay area and use GTL technology to convert
natural gas to middle-distillate (diesel-like) liquids. The GTL product
could be pumped in segregated batches through the Trans Alaska oil
pipeline and then transported by tankers to the U.S. West Coast. A
50,000 bpd (0.5 bcfpd or 0.2 tcf/yr) plant has been promoted by one
group, but BP-Amoco, a major owner of the gas at Prudhoe Bay, is
presently building a small experimental GTL plant at Nikiski in Cook
Inlet, Alaska (operational in 2002).
The original proposal for a gas pipeline through Canada—the Alaska
Natural Gas Transportation System (ANGTS) and now sometimes called the
"Highway Route"—followed the Dalton Highway from Prudhoe Bay
to Fairbanks and then followed the Alaska Highway to central Alberta. A
1995 study published by the ANGTS group (abstr. by Thomas and others,
1996, p. 3-4) estimated that delivery costs for their $16.7 billion
project would range from US$2.82/mcf to US$4.17/mcf in $1995 (or $3.29/mcf
to $4.86/mcf in $2000). A similar "highway" gas pipeline project
now being studied by the Prudhoe Bay gas owners would cost US$10 billion
(2.5 bcfpd line) to US$12 billion (4.0 bcfpd line) and could profitably
deliver gas to Chicago for $3.50/mcf (Meyers, 2000). Chicago city gate
prices were approximately $8/mcf in January 2001. U.S. domestic natural
gas demand, now at 22 tcf/year, is predicted to rise to 35.57 tcf/year by
year 2020 (AEO, 2000, tbl. A1), thus ensuring a future of strong demand
for any gas that can be profitably brought to the U.S. market from
northern Alaska or Canada.
Alaska has the only LNG export operation in the U.S. Small amounts of
LNG (0.06 tcf/year) from gas fields in Cook Inlet have been sent to
Yokohama, Japan since 1971. A much grander LNG export model, shipping
perhaps 0.9 tcf/year, has been proposed by Yukon Pacific Corporation for
moving gas from northern Alaska into the Asian Pacific Rim and U.S. West
Coast markets. The LNG project at the largest scale would require
construction of a new gas conditioning plant at Prudhoe Bay, an 800-mile
gas pipeline, a new LNG plant and marine terminal at Valdez in southern
Alaska, and a new LNG tanker fleet, all for approximately $12.76 billion
($2000). No economic studies of the most recent LNG proposals are publicly
available. A 1995 study by Thomas and others (1996) using a 0.85 tcf/yr
LNG project costing $16.03 billion ($1995) found that a flat world oil
price of $19.36/bbl ($1995) was required for the LNG project to
economically "breakeven" (NPV10=0). The AEO (2000) Reference
Case forecasts that world oil will reach this price in year 2015. A
$19.93 world oil price is approximately equivalent to an LNG price of
$3.77/mcf (in September 2000, Cook Inlet LNG shipments to Japan were
receiving $4.33/mcf). A 1999 DOE update study by Robertson (1999) found
the LNG project to be unprofitable (NPV10= — $2,402 billion),
in fact providing the poorest return of all marketing concepts modeled by
that study. An LNG export volume of 0.9 tcf/year would be equal to a very
large fraction (28%) of the entire 1998 Asian Pacific rim LNG market
(3.225 tcf/year). The chief risk element of the LNG proposals is that such
large exports might flood the principal market and cause a price collapse.
Because of market risk and capital cost considerations, plans for smaller
initial LNG-based projects (output as low as 0.46 tcf/year, costing $8.2
billion to construct) have also been proposed, but the economics of the
smaller scale projects are not publicly available.
Gas-to-liquids (GTL) technology forms an attractive option because it
can supplement the throughput of the Trans Alaska oil pipeline (TAPS) and
perhaps extend the operating life of this critically important oil
transportation system decades into the future. The addition of GTL liquids
to the oil transportation system would also moderate per-barrel oil
pipeline tariffs, which are expected to rise in the future as the volume
of pipeline throughput falls. The continued existence of the oil pipeline
and a lowering of future oil pipeline tariffs are critical to the
economics of future development of smaller, undiscovered oil fields in
northern Alaska and the Arctic Federal offshore. A 1995 study by Thomas
and others (1996) of a hypothetical 300,000 bpd (3 bcfpd or 1.1 tcf/yr)
northern Alaska GTL project costing $13 billion found that a
"breakeven" (NPV10=0) flat world oil price of
$19.94/bbl ($1995) was required for economic viability. The AEO (2000) Reference
Case forecasts that world oil prices will not reach this price until
after year 2020. However, in September 2000, the actual world oil price
averaged $31.10/bbl (or $26.69/bbl in $1995). GTL, or at least its modern
component processes, involve relatively new technologies that are only now
entering commercial applications. A recent study of northern Alaska GTL
economics by Robertson (1999) revealed that incremental construction of
several small GTL facilities allowed for "learning"—resulting
in cost reductions to facilities built later in the life of the project.
This "incremental" GTL model provided the most favorable
economic outcome. Future market demand for GTL product is expected to be
robust. The chemical conversion of natural gas to liquid hydrocarbons
creates an essentially refined product that is free of polluting agents
and that as a transportation fuel can command premium market prices,
particularly on the U.S. West Coast, where ultra-clean motor fuels will be
mandated.
The gas transportation system that is eventually constructed to take
Prudhoe Bay gas reserves to market will be scaled to the known reserve
volumes. For this reason, the gas transportation system will be completely
filled for years after start up with production from Prudhoe-area gas
fields. Newly-discovered gas will have to await declines in the area
production levels such that excess capacity (unfilled space) develops in
the gas transportation system. If we assume that a gas pipeline to Prudhoe
Bay is operational by year 2007 and that excess capacity becomes available
after 90 percent depletion of known reserves, the earliest shipments of
newly-discovered gas would be in year 2015 for an 8 bcfpd line, or year
2023 for a 4 bcfpd line, or year 2033 for a 2.5 bcfpd line. An 8 bcfpd gas
pipeline has not been proposed but this is the present rate of gas
recycling in the Prudhoe-area fields. There are currently proposals for
the two smaller pipelines, of which the 4 bcfpd pipeline seems to be
favored. Of course, if substantial new gas discoveries justified
the additional expense, increasing pipeline pressure (adding compression
equipment) could increase pipeline capacity at any time.
Northern Alaska and its contiguous continental shelves are richly
endowed with natural gas. However, finding and developing any significant
fraction of this undiscovered resource will prove very costly. At the
current slow pace of leasing, exploration, and development, a significant
fraction of the undiscovered natural gas endowment of northern Alaska
could remain unavailable to meet market demands for many decades.
Because of the long lead-time required for major construction projects,
the time may now be at hand for decisions about how to export the stranded
natural gas reserves of northern Alaska and northwestern Canada. These
decisions will lead to construction of a huge natural gas marketing
infrastructure costing billions of dollars. Gas production strategies and
new infrastructure will determine the character of oil and gas development
in northern Alaska and northwestern Canada for many decades to come.
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