Kherlen Batbayar1 ([email protected]), Lesli J.
Wood1, J. Frederick Sarg1
1 Department of Geology and Geological Engineering, Colorado
School of Mines
PROBLEM
www.geo.arizona.edu www.geo.arizona.edu
http://pages.uoregon.edu/
Mann et al., 2005
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KEY QUESTIONS
PROBLEM
STUDY AREA DATA
Kh1 borehole data
OBSERVATIONS
ACKNOWLEDGEMENT
HYPOTHESES
Depositional, stratigraphic and oil potential assessment of the
Middle Jurassic Eedemt Formation and Lower Cretaceous Zuunbayan
Formation in the Choir-Nyalga, East Gobi, and Central Gobi
lacustrine basins of Mongolia
• Richness differences between samples in Mongolia are a
function of them being different temporal deposits
• Mongolia is a developing country in desperate need of energy
independence and economic stability much like Jordan.
• Oil shale became the promising new source of energy and
income.
However, after 5 years of exploration by companies like Genie
Energy LLC, ENEFIT Estonia, etc, the subsurface oil shale was found
to be much lean and not economically viable shale oil for
development compared to the surface samples.
FUTURE WORK
• The Khoot subbasin samples, from both outcrop and subsurface,
have been analyzed and determined to be dominantly Type 1
lacustrine oil shales.
• Data are available from five subsurface, two of which have
locations that are currently known - KH2 and KH4.
• There is a progressive increase in TOC and IO values from KH1
through KH7.
• KH4, located most proximal to outcrop samples, shows the most
similarity to outcrops in terms of geochemistry.
• KH2 appears to be located in the deepest part of the Khoot
sub-basin, but it shows very low TOC and OI values.
OB-DH-5, oil shale with
fauna, int. 298.5 m
• Outcrop samples lie along the margins of the basins, where
analogs show us source rocks can be very lean, as opposed to lying
in the basin-centered, high richness shales.
• Most of the data available are from the Khoot subbasin of the
Central Gobi basin.
• The image on the left is of a oil shale core taken in
the Overjargalant Basin, Mongolia. It contains age significant
fauna.
• The seismic line below cuts through the Khoot, Choir, Khashaat
Khudag, and Olongiin Uhaa sub-basins of the Central Gobi, Choir
Nyalga, and East Gobi basins (with stars inside).
A Bouger gravity anomaly map for the Khoot sub-basin is overlain
with TOC values for surface samples, samples from two shallow
boreholes and sample from KH2 and KH4. Graphs to the right show
variability of TOC with depth in the two shallow boreholes shown.
The richest surface samples appear to be overlain by a thick
blanket of Quaternary age sediments, possibly influencing their
organic content?
Isostatic residual anomaly map by Guy et al (2004) shows that
subbasins associated with the richest oil shale deposits might be
located more to the east of Block 25 (in yellow) as well as to the
left of the Khoot study area (in black) within Block 25. These
observations are consistent with the hypothesis that the richest
oil shales are located basin-ward.
KHOOT SUB-BASIN GEOCHEMICAL ANALYSIS KH1 borehole data
KH2 borehole data KH4 borehole data
KH5 borehole data KH7 borehole data
• Explore the nature of the lacustrine sub-basin relative to the
larger lacustrine basins.
• Locate other wells provided and continue to assess
geochemistry data relative to basin geography.
• Compare and contrast the Mongolian basins to those of the
Uinta and Piceance as analogs to source rock distribution.
• Quantify the total in place shale oil in the selected
basins.
• Why do the surface samples have profoundly higher TOC values
than the outcrop-proximal subsurface samples?
• Do the large
Mongolian lacustrine basins (BEIGE) have their richest organic
content deposits in their centers, similar to lacustrine basins
such as the Uinta and Piceance Basins of North America?
• If not, then where ARE the richest organic content deposits in
these Mongolian basins, and what is the total in place shale oil in
these basins?
Eastern Mongolian Basins
KH2
KH4
Shallow borehole 2
Shallow borehole 1
• I thank my wonderfully supportive advisors Dr. Lesli Wood and
Dr. Rick Sarg, as well as Dr. Jerry Boak.
• And special gratitude to Genie Energy Mongolia Ltd’s chief
geologists Dr. Yuval Bartov for making this research possible by
donating data.
Source: USGS
Source: USGS
