Genesis and organic geochemical characteristics of oil shale in Eastern Azerbaijan

Abstract

The paper presents a study on genesis and organic geochemical characteristics of oil shales, occurred in different tectonic zones of Eastern Azerbaijan. Lithostratigraphic properties of oil shale containing sediments, evolutionary dynamics and structural types of organic matter were studied. In terms of paleogeography, it was defined that the formation of oil shales in examined regions, are associated with an almost identical sedimentation conditions (in shallow freshwater and silty pools - lagoons). The organic matter of the oil shales is mainly consist of phytoplankton (algae) and zooplanktons (fish larvae etc.). Connected with orogenic phases, the formation of oil shale, coal and oil in southeastern slope of the Greater Caucasus links their similar genetic properties. Thermal analysis of oil shale revealed that when organic matter loses the most part of its weight at a higher temperature (≥400 °C) corresponds to aliphatic, but at lower temperatures (≥200 °C) aromatic structures. Pyrolysis of oil shale samples showed that in the initial stage (500-550 °C), excluding the amount of gas, bitumen and pyrolytic water were increased. Increasing the temperature up to 800-850 °C leads to the conversion of higher molecular hydrocarbons into lower, and formation of gases and coke residues. The gradual increase in temperature ends with carbonization of kerogen. An abrupt change in the yielding of bitumen is mainly observed at a temperature of 400 °C. Thermal analysis and pyrolysis of oi shale samples, taken from different studied regions allow making conclusion that some of their kerogens is fully matured.

Full text

4
1. Introduction and Background
Oil shales in Eastern Azerbaijan are insignificantly
related to Cretaceous but the major known outcrops
are found in the Paleogene-Miocene deposits. The
total number of outcrops is more than 60 in the
republic. The most often oil shales are recorded in
Shamakhi-Gobustan region, where more than 50%
of outcrops are located. In addition, the outcrops
have been also found in Absheron, Ismayilli and
Guba-regions [1, 2] (fig.1).
Initial studies of oil shales in Azerbaijan were
carried out in the last century by Azerbaijani and
Russian scientists. Until end of the XX century these
sediments were investigated at various aspects in
studies of several researchers. The studies were
devoted of the short geological and geochemical
descriptions of the oil shales cropping out on the
surface [3-10].
Since 2000, the studies on the oil shale were
continued at the Institute of Geology and Geophysics.
Specialists of Department of «Mud volcanism» have
been conducting researches on geology, geochemistry,
probable resources and industrial application of oil
shales on the basis of the researches, that have been
carried out in other countries [11-26].
In this study, stratigraphy and genesis of oil
shales in Azerbaijan were investigated. In addition,
a big part of the paper is devoted to the types and
changes of organic matter in the oil shales during
different stages of lithogenesis.
2. Distributional areas of oil shale in
Azerbaijan
Shamakhi-Gobustan region occupies a vast area
of the southeastern margin of the Greater Caucasus
and is characterized by complex tectonic structure.
The geological structure of the region is mainly
consisting of the Mesozoic and Cenozoic sediments.
There are more than 30 oil shale outcrops, and oil -
GENESIS AND ORGANIC GEOCHEMICAL CHARACTERISTICS
OF OIL SHALE IN EASTERN AZERBAIJAN
Ad.A.Aliyev*, O.R.Abbasov, A.J.Ibadzade, A.N.Mammadova
Institute of Geology and Geophysics, ANAS, Baku, Azerbaijan
SOCAR Proceedings No.3 (2018) 004-015
A b s t r a c t
The paper presents a study on genesis and organic geochemical characteristics of oil
shales, occurred in different tectonic zones of Eastern Azerbaijan. Lithostratigraphic
properties of oil shale containing sediments, evolutionary dynamics and structural
types of organic matter were studied. In terms of paleogeography, it was defined
that the formation of oil shales in examined regions, are associated with an almost
identical sedimentation conditions (in shallow freshwater and silty pools - lagoons).
The organic matter of the oil shales is mainly consist of phytoplankton (algae) and
zooplanktons (fish larvae etc.). Connected with orogenic phases, the formation of oil
shale, coal and oil in southeastern slope of the Greater Caucasus links their similar
genetic properties. Thermal analysis of oil shale revealed that when organic matter
loses the most part of its weight at a higher temperature (≥400 °C) corresponds to
aliphatic, but at lower temperatures (≥200 °C) aromatic structures. Pyrolysis of oil
shale samples showed that in the initial stage (500-550 °C), excluding the amount
of gas, bitumen and pyrolytic water were increased. Increasing the temperature up
to 800-850 °C leads to the conversion of higher molecular hydrocarbons into lower,
and formation of gases and coke residues. The gradual increase in temperature
ends with carbonization of kerogen. An abrupt change in the yielding of bitumen is
mainly observed at a temperature of 400 °C. Thermal analysis and pyrolysis of oil
shale samples, taken from different studied regions allow making conclusion that
some of their kerogens is fully matured.
Keywords:
Oil shale;
Genesis;
Organic matter;
Kerogen;
Tthermal analysis;
Pyrolysis.
© 2018 «OilGasScientificResearchProject» Institute. All rights reserved.
*E-mail: ad_aliyev@mail.ru
http://dx.doi.org/10.5510/OGP20180300356
SOCAR Proceedings
Oil and Gas Fields Exploration, Geology and Geophysics
journal home page: http://proceedings.socar.az

5
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
gas fields in the region [23].
A few oil shale outcrops (Qyzmeydan, Zarat,
Heyberi, Kurkechidagh and etc.) were discovered in
Northern Gobustan. They are related to Cretaceous
sediments which have no commercial value.
Numerous outcrops like Jengichay, Kecheller,
Boyuk Siyeki and others were recorded in Central
and South Gobustan, where the Paleogene-Miocene
sediments are widely occurring. These outcrops
are confined to the Middle Eocene, Maikopian
(Oligocene-Lower Miocene), Konkian and Meotian
successions (Middel-Upper Miocene) (fig.2) [24].
There have been recorded more than 15 oil shale
outcrops in Absheron. The outcrops are mainly
associated with the Upper Maikopian, Konkian
and Meotianian sediments. Upper Meotian oil
shales have been revealed in Binegedi, Fatmayi,
Saray, Ateshgah and other anticlines. Oil shales
tied to the Maikopian sediments have been found
in the west part of Absheron. In the border
with Shamakhi-Gobustan region, there are only
two (Goytepe and Uchtepe) oil shale outcrops,
which are related to the Middle Eocene (Koun)
sediments.
In studied sections oil shale beds of different
thickness are alternating with other rocks.
Sometimes, the signs of bitumen traces are
recorded in these sections. For example, such a
feature was revealed in the Konkian-Karaganian
(Middle Miocene) sediments in Zigilpiri outcrop.
Fig.1. Location map (1:1000000) of oil shale fields in Azerbaijan [2]
Oil shale outcrops: 1 – Guba; 2 – Zarat; 3 – Bakhyshly; 4 – Diyally; 5 – Heyberi; 6 – Qyzmeydan;
7 – Altyaghaj; 8 – Kemishdagh; 9 – Embizler; 10 – Charqyshlaq; 11 – Kurkechidagh; 12 – Talyshnuru;
13 – Khilmilli; 14 – Aghdere; 15 – Yashma; 16 – Engekheran; 17 – Shamakhi; 18 – Erebshalbashy;
19 – Shabandagh; 20 – Jeyirli; 21 – Goredil; 22 – Qaraja; 23 – Tuva; 24 - Qibledagh; 25 – Ahudagh;
26 – Sheibler; 27 – Kichik Siyeki; 28 – Boyuk Siyeki; 29 – Qarayokhush; 30 – Jengidagh; 31 – Jengichay;
32 – Kecheller; 33 – Pirekeshkul; 34 – Aghburun; 35 – Islamdagh; 36 – Mayash; 37 – Goytepe;
38 – Orjandagh; 39 – Saray; 40 – Jorat; 41 - Guzdek; 42 – Kecheldagh; 43 – Fatmayi; 44 – Bayqushlu;
45 – Alaqyshlaq; 46 – Qaryqyshlaq; 47 – Bayqushqaya; 48 – Sungur; 49 – Bayanata; 50 – Sarıdagh;
51 – Qırdagh; 52 – Shorbulaq; 53 – Kosmalı; 54 – Uchtepe; 55 – Qaraheybet; 56 – Masazyr; 57 – Bineqedi;
58 – Xyrdalan; 59 – Zigilpiri; 60 – Qyrmeki; 61 – Shabandagh; 62 – Ateshgah.

6
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
Fig.2. Location map of oil shale outcrops (linked to the
Middle Eocene-Meotian sediments) in Shamakhi-Gobustan region
Eosene (Koun): 1 – Yashma (Meotian); 2 – Charqyshlaq; 3 – Embizler; 4 – Shamakhi (Upper Maykopian);
5 – Erebshalbashy (Upper Maykopian); 6 – Aghdere (Upper Maykopian); 7 – Shabandagh; 8 – Tuva;
9 – Qarajuzlu (Upper Maykopian); 10 – Kichik Siyeki (Upper Maykopian, Konk); 11 – Jengichay;
12 – Kecheller; 13 – Ashaghykend; 14 – Aghburun; 15 – Pirekeshkul;
 Upper Maykopian: 16 – Engekheran; 17 – Goredil; 18 – Sheibler; 19 – Qibledagh;
20 – Jengidagh; 21 – Bayanata (Meotian);
 Konk: 22 – Islamdagh (Meotian); 23 – Mayash (Meotian); 24 – Boyuk Siyeki (Meotian);
25 – Sungur (Meotian); 26 – Bayqushqaya (Meotian);
 Meotian: 27 – Jeyirli; 28 – Ahudagh; 29 – Bayqushlu; 30 – Alaqyshlaq; 31 – Qaryqıshlaq;
32 – Sarydash; 33 – Qyrdagh; 34 – Kusmelidagh
True thickness,
m
Gray and brown gray finely «laminated» oil shale, oil smell 0. 63
Dark gray «laminated» shales 0.15
Gray and dark gray oil shales 0.42
Low sandy gray shales 2.31
Gray, brown gray, sometimes dark gray and thick
«laminated» oil shale, oil films along bedding planes 1.31
Gray, dark gray and dense «laminated» shales 5.9
Gray, dark gray and sometimes brown gray oil shale, oil smell 2.35
Gray, dark gray and sometimes brown gray shales 0.42
Gray and dense shales 0.63
Gray, dark gray, brown gray oil shale with oil films 2.52
Thick «laminated» and dense gray shales 8
Gray and brown gray, and sometimes dark gray oil shale, oil smell 1.36
Below we submit a lithological description of this succession:

7
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
The oil shale outcrops of the Maikopian Series
(Oligocene-Lower Miocene) were observed only
in the north-western part of Pre-Caspian-Guba
region, but they do not draw attention to their
economic efficiency.
Oil shale outcrops of the Konkian sediments
having thickness 8 - 15 m have been developed on
the Chandagar River banks. The Meotian sediments
were recorded in the southeast of Shuraabad field.
Two oil shale beds have been described in the
section of the Meotian in the Yashma area.
Oil shales in the Guba area are dated by the
Upper Sarmatian. There is section consists of oil
shale beds, ranging in thickness from 27 to 255
m and alternating with shale beds, which hardly
can be differentiated from oil shales. The greatest
practical interest is assosiated with the oil shale
bed of the Upper Sarmatian, which occurs 29 km
to the NW-SE from Gudiyalchay River toward
Velvelechay River [12] (fig.3). Several individual
outcrops of oil shales have been found near the
Gilgilchay River and as well as to the north-west
of Gudiyalchay River, between the watershed
Gusarchay-Tahirjalchay and village Anig.
Thick oil shales were recorded in the area
between rivers Velvelechay and Garachay. There
are three localities, known by the most favorable
properties for practical use. 11 oil shale beds have
been recorded in the section trending for 4.7 km
in the first locality. The second section is located
between rivers Kamalchay and Chagachukchay
and there are 14 oil shale beds in a section
matching for 3 km. The third oil shales containing
section consists of 16 oil shale beds occurring
within the area of 1.5 km and located on the right
bank of Garachay River [12].
The Diyally outcrop is located 7 km east of
Ismailly city. Tectonically, the area relates to
the Vandam Lahij zone. There were discovered
two troughs (moulds), composed of Sarmatian
sediments and occurring for a distance of 1.5 km.
The thickness of oil shales is 300-370 m, in the
north they are covered by the thrust of Kemchi
suite limestone (Cretaceous) (fig.4).
3. Genesis and organic geochemistry of oil
shales
Oil shales in the upper horizons of Miocene
occur in Gobustan, Absheron and Guba and were
comparatively studied. In the example of all
three mentioned regions, some lithostratigraphic
characteristics of oil shale are described in table 1.
In all of these areas, the accumulation of
sediments may almost related to the certain
environment ‒ shallow freshwater and silty pools
(lagoons), which are particularly characteristic for
the first and third sections. In the first section the
ash bed was also recorded.
Taking into account that the coal debris is
presented in the oil shales we tried to reconstruct
the history of oil shale accumulation by analyzing
the coal formation, which is refer to the folding
phases in the south-eastern end of the Greater
Caucasus (fig.5).
The black oil shales with the thickness of 4 m
are related to the Upper Cretaceous (Cenomanian)
sediments in the section of the North Gobustan
(Kemishdagh). There in the section were also
recovered fish larvaes and algae [26]. The most
likely accumulation of these rocks is connected to
the Austrian orogenic phase.
The «laminated» dark brown oil shales in the
section located in the vicinity of village Heyberi of
Shamakhi region composed of marl and dated as
Coniacian-Campanian [27] the most probable are
linked to the Sub-hercian orogenic phase.
In Azerbaijan, oil shale outcrops are mainly tied
to the middle Koun (Middle Eocene) and these
were accumulated during the Laramide orogenic
phase (end of the Cretaceous and beginning of the
Fig.3. Geological map (1:100000) and profile across oil shale fields in Guba area

8
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
Fig.4. Geological map and profiles (1:20000) across Diyally oil shale field

9
Cenozoic).
The oil shales of the Makopian Series is
associated with accumulation that took place after
the Pyrenean orogenic phase.
Oil shales of the Miocene sediments may
accumulate after the Attic orogenic phase.
The formation of brown coals in Vandam zone is
most likely connected to freshwater environment,
which probably existed during the East Caucasian
orogenic phase. This phase corresponds to the time
of accumulation of the Lower Pliocene Productive
Series in the South Caspian basin.
Regarding the genesis of brown coal, oil shales
and oil, it is assumed that accumulation of coal
occur on the banks of the highly vegetated pools;
oil shales - simple flora and fauna (algae, plankton,
fish larvae and etc.); oil - organic matter in subsided
areas in the marine basins. Thus a conclusion on
the transformation of coal, oil shales and oil into
each other can be present in such a form
coal ↔ oil shale ↔ oil
In addition to oil shales, there were traced
bituminous limestone and marls in the same
sections of Gobustan, Diyally and Guba. Chemical
analyzes show that increased percentage of
carbonates leads to the growth of pitch amount,
and decrease of carbonates’ amount - to increased
bitumens. Such a combination between carbonate
and bitumen can probably be explained by the
high content of algaes (Lithotamnium) constituting
oil shales.
Depositional environment of oil shales is
interpreted as sedimentation during sea level high
stand. Additionally, bitumen traces in the oil shale
section (see section Zigilpiri) can be explained in
two ways: occurrence of the source rocks in the
section or the possible due to generation potential
of the oil shales itselves.
To clarify the type and distribution of organic
matter in the oil shales the laboratory experiments
were carried out. The OM type and composition
in oil shales depend on the processes taking
place at the end of diagenesis and OM specific
features. The results of thermal analysis may be
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
Birgut horizon (M.S.Shatski,
V.V.Veber), Gobustan
Upper pack of shales
(I.M.Gubkin), Absheron
Northeastern slope of the Greater
Caucasus, Guba (I.F.Pustovalov)
Ash-brown or light gray oil
shale with abundant diatomic
flora and fish remains. Sometimes
dark colorized bituminous
rocks, dolomite, marl and white
volcanic ash are presented.
Thickness 325-500 m.
Olive-brown and light
gray «laminated» shales,
and siliceous marls. In the
bottom of suite, sometimes
strongly bituminous rocks
are recorded. Thickness 300-
500 m.
Alternation of dark gray shales
and sands. In the bottom of suite were
recorded dark bituminous shales with
numerous fish remains, and limestones,
sandy shales, which rich with fauna. The
apparent thickness of the shale bed is
approximately 20 m. Total thickness up
to 100 m.
Table 1
Lithostratigraphic description of oil shale in the upper horizons
of the Miocene in Gobustan, Absheron and Guba regions
Fig.5. Coal formation corresponding to the folding phases
in the south-eastern end of Greater Caucasus [19]

10
0
2
4
6
8
10
12
Test
№61
Test
№3
Test
№130
Test
№139
Test
№140
Test
№150
Test
№160
Test
№170
Organic matter, %
T, ºC
200
300
400
500
600
700
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
used as a model to explain the natural processes
occurring during the diagenesis and catagenesis.
In this purpose, geochemical characteristics of oil
shales in Guba and Ismayilli regions were studied.
The amount of organic matter in samples ranges
between 17.50 and 32.22%. The major part of
organic matter is concentrated (14.46-31.21%) in
the kerogen part (tabl.2).
Some thermal analyses of samples were carried
out in order to explain decomposition mechanism of
kerogen and determine type of organic matter.
Samples results, of the samples, collected from
Shabranchay and Velvelechay
areas in Guba region show that
the organic matter loses its most
part at the temperature of 200
°C (chart 1). But in sample
№139 this process occurred at
the temperature of 500 °C. The
smooth gradual changes (loss of
6.78-6.49% of OM total amount)
are recorded at temperatures of
200-400 °C.
Depending on the
temperature, the weight loss
process occurred gradually
in the samples collected from
Diyally in Ismayilli (chart 2).
For example, the process starts
at the temperature of 200 °C
(5.14%) in the sample №89. A
little difference is observed at the
temperatures between 300 and 500 °C (5.19 - 5.18%).
The same trend was recorded in samples №87 and
90. In general, the transformation and weight loss of
organic matter start at the temperatures of 300-400 °C
in samples collected from the Diyally area.
These results give a way to explain the process
of hydrocarbon formation in oil shale. Initially the
organic matter exposes to insignificant changes.
Increasing the temperature leads to decomposition
of the weak heteroatomic compounds that exist
between nuclei. The process goes on with releasing
of soluble high molecular heteroatomic components
Sample No. Area Organic matter, % Kerogen, %
61 Guba, Velvelechay 23.84 20.12
3 Guba, Velvelechay 22.38 20.87
130 Guba, Shabranchay 24.63 23.57
139 Guba, Shabranchay 32.22 31.21
140 Guba, Shabranchay 18.33 17.04
150 Guba, Shabranchay 17.50 17.11
160 Guba, Shabranchay 23.43 22.66
170 Guba, Shabranchay 23.13 22.51
87 Diyally 18.33 20.24
89 Diyally 21.17 14.46
90 Diyally 21.13 16.22
96 Diyally 22.33 18.31
99 Diyally 19.32 15.53
103 Diyally 26.32 22.79
105 Diyally 27.88 25.63
106 Diyally 27.17 25.12
Table 2
Geochemical patterns of oil shales of Guba and Ismayilli regions
Chart 1. Results of thermal analysis of oil shales collected from
Shabranchay and Velvelechay areas in Guba region

11
0
2
4
6
8
10
12
Test
№87
Test
№89
Test
№90
Test
№96
Test
№99
Test
№103
Test
№105
Test
№106
Organic matter, %
T, ºC
200
300
400
500
600
700
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
and formation of bitumen, asphaltene and as well
as loss of light components (CH4, H2O, CO2 and
C2H6) in kerogen. In addition, a high degree of
aromatization also occurs (H/C ratio). At the end
the kerogen turns into high molecular heteroatomic
compounds and after that generates relatively small
molecules. In the maturated structure of kerogen,
the aromatic plastic sheets form a subparallel series
and they become more regulated.
According to some authors, depending on
the temperature of OM in coal and oil shales
the time of OM catalytic transformation can be
accelerated [23, 28-35].
As a result of catalytic transformation of
carbonate and mud rocks the organic matter having
condensed aromatic or aliphatic structure is formed.
Abundance of H2 and deficit O2 in the organic matter
of aliphatic structure is characteristic because lack
of polyaromatic compounds and heteroatom bonds.
In organic matter of the aromatic structure
the polyaromatic compounds
and O2-containing functional
groups predominate in
organic material. The long-
chain alkanes and fatty acids
play a minor role in their
composition, but ketone and
carboxylic groups vice versa.
Depending on the temperature,
the decomposition process
goes quickly in the compounds
which are composed of
heteroatomic organic matter.
As organic matter of aliphatic
structure is more resistant to
temperature to get less amount
of heteroatomic compounds in
its composition the additional
temperature is required [35].
Thus, the weight loss of the
organic matter occurs at high
temperatures in aliphatic type
OM, but at low temperatures (200 °C) in OM of
aromatic type.
The results of thermal analysis enable us to note
some regularities and differences. Taking this into
account, the samples collected from the areas Guba
and Diyally were also analyzed by pyrolytic method
in two stages (tabl.3).
Yield pyrolytic bitumen and pyrolytic water
amount was increased at low temperatures, but the
same tendency to the gas volume were recorded
only when the temperature increases. The main
structures of macromolecules in kerogen nearly
were unchanged at the same temperature. The
generation of gas at low and high temperatures was
recorded clearly. Thus, the temperature increasing
results with carbonization and decomposition of
organic matter.
In the samples of Guba (tabl.3) and Diyalli
(tabl.4) areas the bitumen formation is recorded
at temperature up to 550 °C. It was observed that
Chart 2. Results of thermal analysis of oil shale of Diyally area
Sample
No.
Organig
matter,
%
Pyrolyzed
organic
matter,
%
Low temperature
(500-550 °C) High temperature
(800-850 °C) Carbonized
part, %
Pyrolytic
water, % Bitumen,
%Gas,
%Pyrolytic
water, % Bitumen,
%Gas,
%
61 23.84 22.82 10.28 2.21 5.72 0.53 - 4.08 1.02
3 22.38 17.17 4.09 2.40 5.53 1.44 - 3.71 5.21
130 24.62 22.16 12.05 1.82 4.21 0.63 - 3.44 2.46
139 24.22 20.34 13.02 1.56 3.55 0.08 - 2.14 3.88
140 18.33 17.61 6.88 0.34 2.03 1.32 2.78 4.26 0.72
150 17.75 16.50 6.87 0.15 2.87 1.29 - 5.31 1.25
160 23.34 19.73 11.26 1.61 4.63 0.26 - 1.98 3.61
170 23.13 20.92 13.98 0.40 4.31 0.13 - 2.09 2.21
Table 3
Geochemical patterns of oil shales of Guba and Ismayilli regions

12
Table 4
Pyrolysis of oil shale samples of Diyally area
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
in the higher temperature intervals only gas is
produced. Along with the organic part inorganic
matter was also exposed to decomposition process
in the samples of Diyalli area. Amount of bitumen
fractions are more (6.73-12.30%) than other products.
According to the thermal analysis, organic matter
loses its significant part at temperatures ranging
from 300 to 400 °C. Thus, we can conclude that
aliphatic compounds are more than aryl compounds
in the sample samples of Diyalli. Therefore, they
require more energy. Bitumens dominate among
decomposition products.
Amount of bitumen in Guba area samples varies
in 0.40-2.40% limits. According to the thermal
analysis of samples, the weight loss of the organic
matter occurs at 200 °C in many tests. In contrast to
the Diyalli area, the structure of organic matters is
more appropriate to aromatic types in these samples.
The increasing the temperature (800-850 °C)
leads to transformation of large molecules of
kerogen into low molecular hydrocarbons, gases
and coke residues. Summarizing the results, it
can be concluded that increasing amount of gas
corresponds to the temperature increase, but
slowly decrease of bitumen. An abrupt change in
the yielding of bitumen is mainly observed at a
temperature of 400 °C
Since, gradual increase in the temperature results
with carbonization of kerogen. The process is almost
the same for all samples. Although the amount of
products that are produced at low temperatures and
rates of destructive decomposition vary but the final
step is similar.
During the thermal processing the kerogen
composition change can be described as follows
(Scheme 1):
In the same thermal condition, the process of
kerogen decomposition takes place as shown below
(Scheme 2):
Sample
No.
Organic
matter,
%
Pyrolyzed
organic
matter,
%
Low temperature
(500-550 °C) High temperature
(800-850 °C) Carbonized
part, %
Pyrolytic
water, % Bitumen,
%Gas,
%Pyrolytic
water, % Bitumen,
%Gas,
%
87 21.17 22.49 3.23 10.89 5.05 - - 3.32 -
89 20.19 18.80 1.16 6.73 4.52 - - 6.39 1.39
90 21.13 18.93 1.62 8.12 3.94 - - 5.25 2.20
96 22.33 26.61 3.49 11.66 4.97 - - 6.49 -
99 19.32 21.59 2.11 8.46 4.01 - - 7.01 -
103 26.32 26.01 1.03 12.30 5.04 - - 7.73 0.31
105 27.88 24.13 0.17 10.20 3.04 - - 10.72 3.75
106 27.17 25.29 2.78 11.52 4.48 - - 6.51 1.88
Scheme 1. Kerogen composition change
depending on thermal processing
Scheme 2. The stages of kerogen decomposition
depending on thermal processing

13
Conclusion
Lithostratigraphic properties of oil shales from different regions make possible to
conclude on their similar depositional environment. The accumulation of oil shales
is associated with sedimentation, which takes place in shallow freshwater and silty
pools – lagoons environment. The organic compounds of oil shales mainly consist of
phytoplankton (algae) and zooplanktons (fish larvae etc.). Linked to orogenic phases,
the formation of oil shales, coal and oil in southeastern slope of the Greater Caucasus is
related to their similar genetic properties.
The decomposition of most part of the organic material occurs at high temperature
(≥400 °C) in organic matter of aliphatic structure, and at low temperatures (≥200 °C) in
aromatic type organic matter.
Results of pyrolysis of oil shale samples display that at the initial stage (500-550 °C),
amount of bitumen and pyrolytic water increases. At the same stage amount of gases
increases when the temperature rises too. Increasing the temperature up to 800-850 °C
leads to the transformation of high molecular hydrocarbons into low ones, gases and coke
residues. The gradual increase of the temperature results with carbonization of kerogen.
An abrupt change in the yielding of bitumen is mainly observed at a temperature of 400 °C.
Thermal analysis and pyrolysis of oil shale samples taken from different studied
regions allows making conclusion that some kerogens of the Diyalli area (in the samples
no. 99, 103 and etc.) are fully matured.
In general, the transformation of oil shales may be starts with organic matter change
in the diagenesis stage and destruction of long aliphatic C-C bonds in catagenesis stage;
continuing separation of minerals and organic matter from each other in the composition
of kerogen is completed with the hydrocarbon formation.
Ejected products of mud volcanoes, widely developed in Absheron and Shamakhi-
Gobustan regions, are supplied from the depth of 6-8 km and more. These products are
sole data, which contain information on geology of deep sediments of region that are
not assessable with drilling. Sometimes oil shale and bitumen rocks are found among
the volcanic products of Eocene-Miocene age [23, 24, 36-39]. Geochemical and geological
studies of oil shales and bituminous rocks of volcanic ejectas bring to understanding of
hydrocarbon generation potential of these sediments and their possible accumulation at
certain stratigraphic levels. It also creates opportunity to explore shale gas accumulations
in Azerbaijan.
References
1. Ad.A.Aliyev, O.R.Abbasov, A.J.Ibadzade, A.N.Mammadova. Prospects of usıng of Azerbaıjan oil shale //News
of ANAS. -2015. –Vol. 2. -No.1. -P. 43-47.
2. Ad.A.Aliyev, A.A.Bayramov, O.R.Abbasov, A.N.Mammadova. Reserves of oil shale and natural bitumen //
National Atlas of the Republic of Azerbaijan. Map (Scale 1:1000000). State Land and Cartography Committee,
2014. -P. 101 3. V.V.Veber. Geological studies of SE part of Kabristan (Boyan-ata) pastures. Leningrad: Ed.
Geolkom, 1929.
4. V.V.Bogachev. Geological expedition in the vicinity of Baku. Baku: Aznefteizdat, 1932.
5. V.V.Veber. The problem of the Paleogene and Miocene oil-bearing layers in Gobustan. Leningrad: GONTI, 1939.
6. A.D.Sultanov, R.G.Sultanov. Materials on oil shales in Azerbaijan //Proceedings of the Academy of Sciences
of the Azerb. SSR. -1947. -No. 2. -P. 18-20.
7. R.G.Sultanov. Oil shale of south-eastern Caucasus and geological conditions of their distribution. Baku:
Fund IGANA, 1948.
8. A.A.Ali-zade, G.A.Ahmedov, M.M.Zeynalov. Oil shale of the Miocene in Azerbaijan //Azerbaijan Oil
Industry. -1962. - No. 1. -P. 5-8 9. P.E.Volarovich. The oil-bearing areas of Kirmaku-Binagadi //Minerals. -1976.
-Issue. 149. - P. 189-208.
10. S.G.Salaev, Z.Y.Kravchinsky, A.I.Selimhanov, et al. Oil sands and oil shale in Azerbaijan. Baku: Science, 1990.
11. Ad.A.Alyiev, I.S.Belov, H-M.A.Aliev. Oil shale of the Miocene in Azerbaijan //Azerbaijan Oil Industry.
-2000. -No.5. -P.7-11 12. Ad.A.Aliyev, I.S.Belov, A.J.Ibadzade. Oil shale of Azerbaijan (geology, geochemistry
and prospects of their use) //Proceedings of the Institute of Geology. -2002. -No.30. -P.5-24.
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
This work was supported by the Science Development Foundation under the President of the
Republic of Azerbaijan ‒ Grant № EİF-KETPL-2-2015-1(25)-56/32/2

14
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015
13. O.R.Abbasov. Geological and geochemical characteristics of oil shale in Gobustan (Azerbaijan) and their
probable reserves //Bulletin of Atyrau Institute of Oil and Gas. -2008. -No. 2 (14). -P. 22-29.
14. A.J.Ibadzadə, O.R.Abbasov. Geochemistry of oil shale in Gobustan and application areas of pyrolysis
products //Proceedings of the Institute of Geology. - 2008. - No. 36. - P. 58-67.
15. O.R.Abbasov. Oil shale of Azerbaijan: geology, geochemistry and probable reserves //International Journal
of Research Studies in Science, Engineering and Technology. - 2015. - Vol. 2, - No. 9. - P. 31-37.
16. M.A.K.Barakat, E.A.Abd El-Gawad, M.F.W.Gaber, et al. El-Nakheil oil shale: A promising resource of
unconventional raw material for fuel and energy in Egypt //International Journal of Current Research. - 2015.
-Vol. 7. -Issue 12. -P. 24511-24514.
17. Y.J.Lee. Geochemical characteristics of organic matter in the Tertiary sediments from the JDZ Blocks,
offshore Korea //Korean Journal of Petroleum Geology. -1997. -Vol. 6. -P. 25-36.
18. S.Tao, Y.B.Wang, D.Z.Tang, et al. Organic petrology of Fukang Permian Lucaogou Formation oil shales
at the northern foot of Bogda mountain, Junggar Basin, China //International Journal of Coal Geology. -2012.
-Vol.99. -P. 27-34.
19. K.Urov, A.Sumberg. Characteristics of oil shales and shale-like rocks of known deposits and outcrops //Oil
Shale. - 1999. - Vol. 16 (3). - P. 1-64. Tallinn: Estonian Academy Publishers.
20. V.Yefimov. Creation of an oil shale industry in Kazakhstan may become a reality //Oil Shale. -1996. -Vol.13.
-P. 247–248.
21. S.Vanichseni, K.Silapabunleng, V.Chongvisal, P.Prasertdham. Fluidized bed combustion of Thai oil shale //
Proceedings of International Conference on Oil Shale and Shale Oil. Beijing. - 1988. - P. 514–526.
22. O.R.Abbasov, A.N.Mamedova, A.R.Huseynov, et al. Some new data about geochemical investigations of oil
shale in Azerbaijan //Geology, Geophysics and Development of Oil and Gas Fields. - 2013. - No. 2. - P. 32-35
23. O.R.Abbasov. Organic compounds in ejected rocks of mud volcanoes as geological and geochemical
indicators of source rock: a study of oil shale in Shamakhi-Gobustan region (Azerbaijan) //International Journal
of Current Advanced Research. - 2016. -Vol. 5. -Issue 7. –P. 1042-1046.
24. O.R.Abbasov. Geological and geochemical properties of oil shale in Azerbaijan and petroleum potential of
deep-seated Eocene-Miocene deposits //European Journal of Natural History. -2016. -No. 2. -P. 31-40.
25. V.P.Rengarten. Tectonic characteristic of folded regions in Caucasus. Transactions of III All-Union Congress
of Geologists. Tashkent : Sredne-Asian. otd. geologist. kom., 1930.
26. M.F.Mirchink. Stratigraphic correlation of the Paleogene and Cretaceous suite in south-eastern Caucasus //
Azerbaijan Oil Industry. -1931. -No. 2-3. -P.11-14 .
27. Z.A.Mishunina. Essay on stratigraphy of Mesozoic deposits in Khaltan-Lahij region (Southeastern
Caucasus). Leningrad-Moscow: GONTI, 1939.
28. I.S.Guliyev, V.Yu.Kerimov, R.N.Mustaev, A.V.Bondarev. The estimation of the generation potential of the low
permeable shale strata of the Maikop Caucasian series // SOCAR Proceedings. -2018. -No. 1. -P. 4-20.
29. I.S.Guliyev, V.Yu.Kerimov, A.V.Osipov, R.N.Mustaev. Generation and accumulation of hydrocarbons at great
depths under the Earth's Crust // SOCAR Proceedings. -2017. -No. 1. -P. 4-16.
30. A.M.Salmanov, B.I.Maharramov, R.M.Huseynov, E.F.Xalilov. Tectonic features of miocene sediments of
South-West Apsheron in accordance with the new data //SOCAR Proceedings. -2016. -No. 1. -P. 4-12.
31. B.B.Huseynov, A.M.Salmanov, B.I.Maharramov. Prospect estimation of the shale HC maykop deposits river
interfluves of Kura and Gabirri //SOCAR Proceedings. -2017. -No. 4. -P. 4-15.
32. O.R.Abbasov. Distribution regularities of shales of Paleogene-Miocene sediments in Gobustan. Abstract of
PhD thesis. Baku: Institute of Geology and Geophysics, ANAS, 2009.
33. A.Aliyev, O.Abbasov. Organic geochemical characteristics of oil shale in Azerbaijan //PRoceedings of the
36th National and the 3rd International Geosciences Congress. Tehran, Iran: February 25-27, 2018. -P. 1-10.
34. O.R.Abbasov. Distribution regularities and geochemistry of oil shales in Azerbaijan //Mineral Resources of
Ukraine. -2017. -No. 2. -P. 22-30.
35. B.S.Aslanov, B.I.Magerramov, A.I.Huduzade. To the assessment hydrocarbon potential zone buried uplifts
«Saatli-Goychay-Mugan» // SOCAR Proceedings. -2016. -№ 2. -P. 4-10.
36. Ad.A.Aliyev, A.D.Ibadzadeh, O.R.Abbasov, A.N.Mammadova. The dynamics of genesis of organic matter in oil
shales //Azerbaijan Oil Industry. -2014. -No. 7-8. -P. 3-7.
37. F.R.Babayev, O.R.Abbasov, A.N.Mamedova, et al. Study of bitumen of Azerbaijan //Actual Problems of the
Humanities and Natural Sciences. -2013. -No. 7. -P. 40-42.
38. O.R.Abbasov. Distribution regularities of oil shale in Azerbaijan //Theoretical & Applied Science. -2016.
-No. 3(35). –P. 165-171.
39. O.R.Abbasov, A.D.Ibadzade, A.B.Khasayeva, et al. Hydrocarbon potential of deep deposıts in Gobustan
(Azerbaıjan) (based on oil shale and oil-bearing rocks in ejecta of mud volcanoes) //in book: Resources
reproducing, low-waste and environmental technology development of mineral resources. Proceedings of the
XIV International Conference. Kyrgyzstan, 2015. -P. 342-343.

15
Генезис и органические геохимические характеристики
горючих сланцев в Восточном Азербайджане
Ад.А.Алиев, О.Р.Аббасов, А.Д.Ибадзаде, А.Н.Мамедова
Институт геологии и геофизики НАН Азербайджана,
Баку, Азербайджан;
Реферат
В статье расмотрены вопросы генезиса и геохимии органического вещества (ОВ) горючих
сланцев различных тектонических зон Восточного Азербайджана. Изучены литостратиграфи-
ческие свойства сланцесодержащих отложений, динамика эволюции и структурные типы ОВ,
образование которых связывается с происходящими в почти одинаковых палеогеографических
условиях (в неглубоких пресноводных бассейнах - лагунах) осадконакоплением. Содержание
ОВ горючих сланцев в основном представлено фитопланктоном (водоросли) и зоопланктоном
(личинки рыб и т.д.). Образование наряду с горючими сланцами проявлений угля и нефти в
орогенных фазах юго-восточного склона Большого Кавказа, объясняется сходством их генети-
ческих свойств. По результатам термического анализа горючих сланцев, потеря ОВ большей
части веса при более высокой температуре (≥400 °C) соответствует алифатическим, а при более
низких температурах (≥200 °C) ароматическим структурам. По данным пиролиза горючих
сланцев увеличивается на начальной стадии (500-550 °С), за исключением газа, количество
битума и пиролитической воды. Повышение температуры до 800-850 °С приводит к превраще-
нию высокомолекулярных углеводородов в более низкомолекулярные; образуется газ и кокс.
Постепенное повышение температуры приводит к карбонизации керогена. Резкое увеличение
в выделении битума в основном наблюдается при температуре 400 °С. Термический анализ и
пиролиз изученных образцов горючих сланцев, отобранных на разных площадях исследуемых
областей, позволяют сделать вывод, что некоторые керогены достаточно созрели.
Ключевые слова: горючие сланцы; генезис; органическое вещество; кероген; термический
анализ; пиролиз.
Şərqi Azərbaycanın yanar şistlərinin genezisi və
üzvi geokimyəvi xüsusiyyətləri
Ad.A.Əliyev, O.R.Abbasov, A.J.İbadzadə, A.N.Məmmədova
AMEA-nın Geologiya və Geofizika İnstitutu, Bakı, Azərbaycan
Xülasə
Məqalədə, Şərqi Azərbaycanın müxtəlif tektonik zonalarında intişar tapmış yanar şistlərin genezisi
və üzvi geokimyəvi xüsusiyyətləri təhlil olunur. Yanar şist saxlayan çöküntülərin litostratiqrafik
xarakteristikaları, həmçinin şistlərin tərkibində çoxluq təşkil edən üzvi maddənin təkamül dinamikası,
sturktur tipi və s. araşdırılır. Onların əmələgəlməsi təqribən eyni palecoğrafi (dayaz və şirinsulu qapalı
hövzələrdə (laqunalarda)) şəraitdə baş vermiş çöküntütoplanma ilə əlaqələndirilir. Şistlərin tərkibindəki
üzvi maddələri, əsasən fitoplankton (yosunlar) və zooplanktonlar (balıq sürfələri və s.) təşkil etmişdir.
Orogen fazalarla əlaqədar olaraq Böyük Qafqazın cənub-şəqr yamacında yanar şistlərlə bərabər, kömür
təzahürlərinin və neftin əmələgəlməsi onların oxşar genetik səciyyələrə malik olması ilə izah olunur. Yanar
şistlərin pilləli termiki təhlili daha yüksək temperaturda (≥400 °C) öz kütləsini azaldan üzvi maddələrin
alifatik, aşağı temperaturda (≥200 °C) itirənlərin isə aromatik tipli struktura uyğunluğunu göstərir. Şist
nümunələrinin priloz nəticələrinə görə, ilk mərhələdə (500-550 °C) neftəoxşar maddələrin (bitum),
piroliz suyunun, həmçinin temperatur artdıqca qazların miqdarı artır. Temperaturun yüksəldilməsi
(800-850 °C) nəticəsində iri molekullu kerogen kiçik molekullu karbohidrogenlərə, qazlara və koks
qalığına çevrilir. Belə nəticəyə gəlmək olar ki, temperaturun artması ilə qazların miqdarı artır, neftəoxşar
maddələrin miqdarı tədricən azalır. Böyük temperatur intervallarında kerogenin kömürləşməsi prosesi
müşahidə olunur. 400 °C temperaturda isə kəskin sıçrayış (bitumun artımında) baş verir. Müxtəlif
sahələrdən götürülmüş yanar şistli nümunələrin termiki analizi və pirolizinin nəticələrinə əsasən, Diyallı
sahəsinin bəzi sınaqlarının kerogenlərini kifayət qədər yetişkən hesab etmək olar.
Açar sözlər: yanar şistlər; genezis; üzvi maddə; kerogen; termiki analiz; piroliz.
Ad.A.Aliyev et al. / SOCAR Proceedings No.3 (2018) 004-015