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OIL SANDS
ENERGY POLICY & FORECASTS
BITUMEN FROM TAR SANDS SEEN AS
HYDROCARBON FOR THE 21ST CENTURY
The long-awaited development of the world's
large resources of heavy oil and tar sands never
materialized in the 1980s and is not likely to be
harnessed in the 1990s. There is good evidence,
however, that these resources will play a
prominent role early in the coming century. That
is the conclusion reached by G. Stosur, of the
U.S. Department of Energy, and S. Karla, of
AGIO Oil and Gas Corporation, in a paper
prepared for the International Conference on
Problems of Complex Development and Produc
tion of Hard-Accessible Oils and Natural
Bitumens, held in Kazan, Tatarstan last fall.
Worldwide resources of bitumen are estimated at
over 3,000 billion barrels, with 62 billion barrels of
in situ bitumen in the United States. This com
pares with a worldwide estimate of conventional
crude oil reserves of 997 billion barrels, of which
25 billion barrels are in the U.S.
U.S. tar sand resources are separated into two
categories, depending on the degree of certainty
about the extent and nature of the resource:
- The
- The
measured resource, defined as the
bitumen resource defined with core and
log analyses
speculative resource, defined as the
bitumen that is presumed to exist from
reported tar shows on drillers'
lithological
logs and/or geological interpretations
The total U.S. tar sand resource is estimated at
61 .9 billion barrels of bitumen in situ. One-third
of this resource is well defined and is in the
measured category, while the remaining
resource is in the speculative range. Measured
resources are concentrated in Utah and Texas,
with over 70 percent occurring in those two
states (Figure 1).
3-10
The physical and chemical characteristics of U.S.
tar sand resources vary widely from deposit to
deposit. Most deposits occur in sandstone and
limestone formations, with the former having
a higher concentration of bitumen.
generally
Some of the minerals and metals that tend to ac
cumulate with bitumen include barium, nickel,
vanadium, titanium and zirconium. For illustra
tive purposes, some characteristics of the richest
U.S. tar sand deposits are shown in Table 1 .
The world's largest tar sand deposits are found in
the Athabasca area of Alberta, Canada. The
measured Canadian resource has been es
timated at 1.7 trillion barrels of bitumen in place,
or about 65 percent of the world's total. In addi
tion to being vastly larger than the U.S. tar sand
prospects, Athabasca deposits are significantly
richer and more concentrated than those found
in the United States. This makes them better can
didates for development.
Technical and Economic Potential for the
Development of U.S. Tar Sands
In response to the requirement by the U.S. Con
gress to evaluate the development potential of tar
sands in the U.S., a major evaluation of the U.S.
tar sand prospects was completed in 1994, in
cluding economic assessment of 26 projects. In
this study, potential bitumen recovery from tar
sands was estimated, assuming two distinct con
ventional recovery processes: surface mining
and steam soak.
The total technically recoverable bitumen from
surface mining methods in the U.S. was es
timated to be approximately 4.9 billion barrels.
Although this process technically can recover as
much as 80 percent of bitumen-in-place, it is also
more costly than the alternative process of steam
soaking. Economic analysis shows that the
threshold price for the most favorable surface
mineable tar sand deposit is approximately
$25 per barrel and that almost one-half of the
technically recoverable target can be produced
as liquid fuel at a price of around $45 per barrel
(Table 2). A significant portion of the production
THE SYNTHETIC FUELS REPORT, JANUARY 1995