• Geophysics and Geophysical Exploration
• /
• v.19 no.1
• /
• pp.29-36
• /
• 2016

Recently, the studies about rock physics model (RPM) in shale reservoir are widely performed. In shale reservoir, the degree of the maturity can be estimated by kerogen and GOR (Gas-Oil Ratio). The researches on the rock physics model of shale reservoir with the amount of kerogen have been actively carried out but not with GOR. Thus, in this study, we analyzed the changes in seismic velocity and density, and AVO (Amplitude Variation with Offset) response depending on changes in GOR and the amount of kerogen. Since the shale consists of plate-like particles, it has vertical transverse isotropy (VTI). Therefore we estimated the seismic velocity and density by using Backus averaging method and analyzed AVO responses based on these estimated properties. The results of analysis showed that the changes in the velocity with the GOR variation are small but the velocity changes with the variation in kerogen amount are relatively larger. In case, GOR 180 (Litre/Litre) which is boundary between heavy oil and light oil, when volume fraction of kerogen increased from 5% to 35%, the P-wave velocity normal to the layering increased 51%. That is, it helps estimating maturity of kerogen through the velocity. Meanwhile, when rates of oil-gas mixture are large, the effect of GOR variation on the velocity change became larger. In case volume fraction of kerogen is 5%, the P-wave velocity normal to the layering was estimated $1.46km/s^2$ in heavy oil (GOR 40) but $1.36km/s^2$ in light oil (GOR 300). The AVO responses analysis showed class 4 regardless of the GOR and amount of kerogen because variation of poisson's ratio is small. Therefore, shale reservoir has possibility to have class 4.

• The Korean Journal of Petroleum Geology
• /
• v.14 no.1
• /
• pp.21-35
• /
• 2008

Oil shale is a fine-grained sedimentary rock that includes organic matter called "kerogen". When the kerogen is heated at moderate temperature, petroleum-like liquids are produced through the kerogen. Although it has been reported that oil shale reserves are enormous in amount, totaling at least 2.9 trillion barrels of oil, a great deal of its reserves still remain untapped. This report presents the viability and recent state of oil shale development, which will further validate the feasibility of oil shale development as well as pertinent technology.

• 한국해양학회지
• /
• v.22 no.2
• /
• pp.87-104
• /
• 1987

The middle Cretaceous stratigraphec section of Deep Sea Drilling Project (DSDP) Site 530 in the Angola Basin is characterized by cyclic interbeds of organic-carbon-rich black shales and organic-carbon-poor red and green claystones, namely the black shale sequence. A number of samples from the black shale sequence were analyzed for the typesand distribution of insoluble sedimentary organic matter(kerogen) in order to give more information on the depositional conditions of the black shales in the Angola Basin. The dominant type of kerogen in the black shale sequence at Site 530 is amorphous organic matter mainly of marine planktonic algal origin. It probably consists of remains of some unfossiliqed dinoflagellates. The cyclic preservation of organic-carbon-rich black shales in the Angola Basin during the mid-Cretaceous could be explained by the low dissolved-oxygen concentration in the warm, saline deep and bottom waters combined with the sluggish circulation within the highly restricted basin, and the periodic high productivity in the surface waters.

• Journal of the Mineralogical Society of Korea
• /
• v.28 no.2
• /
• pp.83-93
• /
• 2015

This study investigated genetic, mineralogical and spectral characteristics of oil shale and coal samples in Dundgobi area, Mongolia. Based the Rock/Eval and Total organic carbon (TOC) analysis, kerogen type, hydrogen quantity, thermal maturity and depositional environment were confirmed. Moreover, the mineral composition of oil shale and coal samples were analyzed by XRD and spectroscopy. The result of Rock Eval/TOC analysis revealed that the samples of Eedemt deposit are immature to mature source rocks with sufficient hydrocarbon potential, and the kerogen types were classified as Type I, Type II and Type III kerogen. On the other hand, the samples from Shine Us Khudag deposit were mature with good to very good hydrocarbon potential rocks where kengen types are defined as Type I, Type II/III and Type III kerogen. According to the carbon and sulfur contents, the depositional environment of the both sites were defined as a freshwater depositional environment. The XRD analysis revealed that the mineral composition of oil shale and coal samples were quartz, calcite, dolomite, illite, kaolinite, montmorillonite, anorthoclase, albite, microcline, orthoclase and analcime. The absorption features of oil shale samples were at 1412 nm and 1907 nm by clay minerals and water, 2206 nm by clay minerals of kaolinite and montmorillonite and 2306 nm by dolomite. It is considered that spectral characteristics on organic matter content test must be tested for oil shale exploration using remote sensing techniques.

• Applied Chemistry for Engineering
• /
• v.2 no.2
• /
• pp.185-191
• /
• 1991

The chemical composition and characteristics of the source rock collected from Dolgorae-1 well in Korea continental shelf block VI( $35^{\circ}$ 18'N.L., $130^{\circ}$ 28'E) have been investigated. An oil show analyzer(OSA) has been used to determine the contents of gas, oil and total organic carbon(TOC). The average TOC value for the sample is found to be 0.59%. The OSA has also provided hydrogen index and $T_{max}$, the maximum temperature which generate maximum hydrocarbons from kerogen. From a $T_{max}$-hydrogen index diagram the type of organic matter in the source rock was estimated to be type III kerogen. The content of bitumen and its molecular weight have been determined by means of extraction method and gel permeation chromatograph, respectively. The physicochemical properties has been studied using X-ray diffraction spectrometer, IR spectrometer and thermogravimetric method. On the basis of the results obtained in the present work, the samples collected from Dolgorae-1 well are evaluated to be poor source rocks.

• Clean Technology
• /
• v.24 no.4
• /
• pp.365-370
• /
• 2018

Oil shale is the sedimentary rock containing kerogen, which is one of the abundant unconventional fuel. In the pyrolysis process, oil, gas and coke are produced from the decomposition of oil shale. In this study, TGA and the continuous pyrolysis of oil shale have been investigated for the clean conversion of oil shale. Effects of reaction temperature and residence time on the pyrolysis conversion and oil production rate have been determined. Conversion of oil shale increases with increasing the reaction temperature and residence time. Optimum conditions for oil production were reaction temperature of $450{\sim}500^{\circ}C$ at the residence time of 30 min.

• Economic and Environmental Geology
• /
• v.21 no.3
• /
• pp.319-329
• /
• 1988

As a factor which can help to understand the genesis of (mata) sedimentary and/or hydrothermal uranium depisits, an interpretation of the role of organic matter associated with uranium mineralization, was attempted with the literature published up to the end of 1986. Laboratory studies, in which diageneis and metamorphism are artificially simulated, can help to elucidate how uranium with particular organic materials are formed and destroyed. Similarly, research involving a variety of techniques is needed to characterize both the soluble organic extracts (bitumen) and the insoluble organic matter (kerogen), separated from uranium ores and associated rocks. In the presence of clay minerals and amorphous oxy-hydroxde minerals, an understanding of the role of organic matter must be prudent and may require the incorporation of multidisciplinary approach (mineralogy, inorganic geochemistry ...).

• Resources Recycling
• /
• v.17 no.6
• /
• pp.62-67
• /
• 2008

Oil shale is a sedimentary rock that contains organic compounds called kerogen that are released as petroleum-like liquids by retorting. In order to evalute oil shale as alternative oil resources, the physical properties of oil shale samples from US and Russia were investigated and Fischer assays were carried out. Thermogravimetric analysis shows that thermal degradation of oil shale consisted of two stage processes, with hydrocarbon release from kerogen followed by $CO_2$ release by carbonate decomposition. Organic compounds in oil shale have an high hydrogen/carbon ratio, and therefore liquid hydrocarbons could be obtained easily. Shale oil yields from Russian and US oil shales by Fischer assay were 12.7% and 18.5%, respectively. The density and boiling point of shale oils are higher than that of Middle East crude oil, indicating that further upgrading processes are necessary for refinery. On the other hands, sulfur contents are relatively low, and the amounts of Vanadium and Nickel are extremely small in shale oil. It was found that paraffins were rich in US shale oil while main components of Russian shale oil were oxygenated hydrocarbons.

• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.487-492
• /
• 1995

The chemical compositions and pyrolysis characteristics of oil shales and source rocks distributed in the southwestern and southeastern parts of the Korean peninsular have been investigated. In order to compare the results of Korean samples with those of shales giving high oil yields, two Colorado oil shale samples and one Paris source rock samples were also investigated. Chemical compositions of the samples were analysed by means of gravimetry, CHN analysis, X-ray diffraction method, inductively coupled plasma atomic emission spectrometry and atomic absorption spectrometry. A custom made pyrolyser and a Rock-Eval system were used for the pyrolysis studies. Pyrolyses of the samples were carried out by means of a temperature controlling device to $600^{\circ}C$ at a heating rate of $5^{\circ}C/min$ with a helium flow rate of $1200m{\ell}/min$. The results of pyrolysis study indicated that Colorado shale samples belong to type I and all the other samples belong to type II.

• Economic and Environmental Geology
• /
• v.32 no.1
• /
• pp.101-111
• /
• 1999

Sedimentary organic matter, exposed to continental surficial environment, reacts with oxygen supplied from the atmosphee and forms carbon-containing oxidation products. Knowledge of the rate and mechanisms of sedimentary organic matter weathering is important because it is one of the major controls on atmospheric oxygen level through geologic time. Under the abiological conditions, the oxidation rate of coal organic matter by molecular oxygen is enhanced by the increase of oxygen concentration and temperature. At ambient temperature and pressure, aqueous coal oxidation results in the formation of dissolved $CO_2$ dissolved organic carbon and solid oxidation products which are all quantitatively significant reaction products. The effects of pH, ultraviolet light, and microbial activity on the weathering of sedimentary organic matter are poorly contrained. Based on the results of geochmical and environmental studies, it is believed that the photochemical reaction should play an important role in the decomposition and oxidation of sedimentary organic matter removed from the weathering profile. At higher pH conditions, the production rate of DOC can be accelerated due to base catalysis. These high molecular weight oranic matter can react with man-made pollutants such as heavy metal ions via adsorption/desorption or ion exchange reactions. The effect of microbial activity on the oxidative weathering of sedimentary organic matter is poorly understood and remains to be studied.