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According to the transversely isotropic theory and weak plane criterion, and considering the mechanical damages due to stress unloading and hydration during drilling, a shale wellbore stability model with the influence of stress unloading and hydration was established using triaxial test and shear test. Then, factors influencing the wellbore stability in shale were analyzed. The results indicate that stress unloading occurs during drilling in shale. The larger the confining pressure and axial stress, the more remarkable weakening of shale strength caused by stress unloading. The stress unloading range is positively correlated with the weakening degree of shale strength. Shale with a higher development degree of bedding is more prone to damage along bedding. In this case, during stress unloading, the synergistic effect of weak structural plane and stress unloading happens, leading to a higher weakening degree of shale strength and poorer mechanical stability, which brings a higher risk of wellbore instability. Fluid tends to invade shale through bedding, promoting the shale hydration. Hydration also can weaken shale mechanical stability, causing the decline of wellbore stability. Influence of stress unloading on collapse pressure of shale mainly occurs at the early stage of drilling, while the influence of hydration on wellbore stability mainly happens at the late stage of drilling. Bedding, stress unloading and hydration jointly affect the wellbore stability in shale. The presented shale wellbore stability model with the influence of stress unloading and hydration considers the influences of the three factors. Field application demonstrates that the prediction results of the model agree with the actual drilling results, verifying the reliability of the model. [ABSTRACT FROM AUTHOR]

Is shale oil "revolutionizing" the global oil market and the geopolitics of oil? If so, how? While two aspects of the shale boom—a new source of supply and a cause for the price collapse in 2014–2015—dominate the conventional wisdom, I argue that the most revolutionary change is the least understood aspect of shale oil—shale oil producers' rise as new swing suppliers due to its unique extraction technique and cost structure. Shale oil producers also differ from traditional swing producers in motives, contexts, and an amount of accessible excess capacity such that while shale oil lowers the medium-term price ceiling, it does not eliminate short-term price volatility. By examining the geopolitics of oil since the advent of shale oil, I analyze how such new market realities have or have not altered the US foreign policy on issues involving possible oil supply disruptions, Saudi Arabia's long-held special status in US grand strategy, rationale for US withdrawal from the Persian Gulf, and the foreign policy of China, the largest oil importer today, and Russia, a major petrostate. [ABSTRACT FROM AUTHOR]

In Estonia, oil shale ash was considered as hazardous waste until the end of 2019 mainly due to its high content of calcium oxide. This limited the use and export of the produced ash. During 2018 and 2019, a study on the overall hazardous potential of Estonian oil shale ash was conducted. In this paper, we present the computational ecotoxic analysis results of fly and bottom ash from oil shale power plants and shale oil production plants. According to recommendations by the European Commission, computational methods are preferred for the evaluation of ecotoxicity. These methods take into account the concentrations of environmentally hazardous compounds. In order to evaluate ecotoxicity in light of hazardous property 14 (HP14, Ecotoxic), 14 different types of fly and bottom ash samples were collected and their trace element concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectroscopy (XRF). This enabled analysing all major ash streams of the Estonian oil shale industry. In turn, the toxicity values were calculated according to European Union regulations. The results showed that oil shale ash samples should not be considered as hazardous regarding HP14 - the resulting summed concentrations remained around ten times under the limit values for all four different calculation methods. For example, the highest result was 3.918% (for a limit value of 25%), indicating the low concentrations of hazardous elements in the investigated material. As a result, oil shale ash, similarly to coal ash, is not consideret to be hazardous as of the beginning of 2020. [ABSTRACT FROM AUTHOR]

The relationship between the carbon dioxide content of carbonates in the bomb calorimeter combustion residues and that in the corresponding oil shale samples originated from different deposits was investigated. As a result, a criterion for applying a correction for undecomposed carbonates to gross calorific value was established. A suitable standard method for determination of gross calorific value of oil shale samples was also suggested. [ABSTRACT FROM AUTHOR]

Coal co-firing experiments were conducted in a 250 MW oil shale fired circulating fluidized bed combustion (CFBC) boiler. The objective of the experiments was to test whether adding coal to oil shale would allow the use of the latter with lower heating value. Bituminous coal was mixed with oil shale and fed into the boiler via existing fuel feeding ports. Two test series were accomplished: 11-29% thermal input of coal mixed with 8.4 MJ/kg oil shale (standard fuel), and 12-32% thermal input of coal mixed with 7.5 MJ/kg oil shale. During the experiments, which lasted in total for 15 days, ash samples were collected and flue gas analysis was performed. The boilers were able to continue work with all the fuel mixtures, but a significant increase of nitrogen oxides (NOx) emissions and heat losses due to unburnt carbon in the bottom and fly ashes were observed. The heat losses can be reduced by upgrading the fuel preparation system, but NOx emissions limit can be reached only with installation of an additional DeNOx system. The ash chemical composition remained similar. Sulphur emissions stayed minimal, but a slight increase of carbon monoxide concentration was noticed. Coal cofiring is possible in oil shale CFBC boilers, but the coal must have low fuel nitrogen content and extra attention to the fuel preparation system has to be paid. [ABSTRACT FROM AUTHOR]

The solid heat carrier (SHC) retorting method, so-called Galoter process, was developed for oil shale processing at the end of the 1940s. Since then the method has undergone several improvements. Nowadays there are different modifications of Galoter process in use -- Petroter, Enefit-140 and TSK-500 technologies. The major differences between these technologies are in sizing (throughput), technical solutions and layouts. Recently a shale oil plant based on a new technology, Enefit-280, was commissioned. Enefit-280 is a technology successor of Enefit-140 where the heating of solid heat carrier is accomplished using the circulating fluidized bed (CFB) combustion technology as opposed to the conventional heat carrier combustion technology in Enefit-140. The CFB technology in Enefit-280 was integrated into the process to improve the performance of SHC heating process and reduce the emissions. Operational experience has demonstrated that the modified technology of SHC oil shale retorting has a potential to play a key role in shale oil production with reduced environmental impact. [ABSTRACT FROM AUTHOR]

Unconventional Shale Energy resources have become an increasingly significant source of oil and natural gas in the United States, Canada and China over the last decade. This rapid growth could not be achieved without research and development activities in this field. Moreover, revolution in unconventional hydrocarbon industries has triggered many research questions from highly engineering aspects to highly political issues in this area. In the current paper, we have attempted to shed a light on the frontier research of this growing knowledge domain. A number of 2489 papers were collected from Science Citation Index-Expanded (SCI-E) and the Social Sciences Citation Index (SSCI) databases. We applied bibliometric methods on collected publications and with the help of CiteSpace III software; co-citation networks of publications were mapped which revealed valuable information on research trends and knowledge gaps existing in this field. Three clusters of intellectual structure identified and analysed and future research opportunities recommended. [ABSTRACT FROM AUTHOR]

Shamakhi-Gobustan and Absheron regions (Azerbaijan) are a part of the South Caspian Basin, which is a subsiding basin located between the colliding of Arabian and Eurasian plates. The intensive rate of sedimentation process creates a favorable condition for the formation of oil shale, hydrocarbon and as well as mud volcanoes in these regions. The purpose of the article. The study of oil shale in Azerbaijan has been mainly devoted to their geological and organic-geochemical characteristics, etc. However, the chemical classifications, provenience, palaeoweathering and maturity characteristics have not been studied. This study is the first attempt to investigate noted issues. The research methodology. 10 samples from the outcrops and eject of mud volcanoes were analyzed. The concentrations of major and trace elements and minerals were measured by “S8 TIGER Series 2 WDXRF”, “Agilent 7700 Series ICP-MS” mass spectrometers and XRD “MiniFlex 600”. The microscopes “Loupe Zoom Paralux XTL 745” and “MC-10” and a digital camera “OptixCam” were used to determine the age of the samples. The major and trace elements in the composition of samples were compared with average shale, NASC, PAAS and average black shale as well as oil shale from the Green River Formation of USA, Kukersit of Estonia, etc. studied in the published literature. A diagram and index were used for the classifications and determination of maturity of rocks. The palaeoweathering characteristic was determined based on CIA versus ICV and some other plots and ratios. Research results. The minerals found in oil shale were classified according to their classes. According to the used classification diagram, it was established that all studied samples correspond to shale. A superiority of clay minerals in the composition of oil shale compared to K-minerals, including K-feldspar was found. The estimates based on geochemistry and some ratios of elements confirm the instability of oxides and minerals, and immaturity of the samples. The values of the CIA, CIA versus ICV plot, etc. confirm moderate to high degree of weathering. The results confirm a conclusion that the original sediments were derived from mafic and intermediate source terrain. The scientific novelty. The scientific analysis presented in the paper is based on several substantial theoretical conclusions, which related to the factual material of research conducted by the co-authors. The mineralogy, classification features, stability characteristics of the major oxides and minerals as well as chemical maturity and palaeoweathering were studied based on the chemical composition of the samples. The practical significance. The results of the current study can be used for the further utilization of oil shale in Azerbaijan and the selection of promising areas in terms of mineral raw materials. [ABSTRACT FROM AUTHOR]

Highlights • Shale plugs were flow-through extracted under controlled confining pressure. • Extraction efficiency was determined based on Rock-Eval S1 and S2. • Solvent flow pathways were analyzed on post-extraction plugs by micro-CT. • Different mobility characteristics of hydrocarbons result in compositional variations. Abstract In order to examine the mobility of hydrocarbons in a lacustrine shale oil system, three cylindrical core plugs from the Eocene Shahejie Formation lacustrine shale oil system in the Jiyang Depression were sequentially extracted with dichloromethane (DCM) in flow-through experiments under controlled stress conditions in a tri-axial flow cell. Orientations of the three sample plugs were perpendicular to bedding (#1) and parallel to bedding (#2 and #3). Post-experiment Micro-CT analysis confirmed three different flow patterns: Cross bedding flow (#1), minor bedding-parallel flow (#2), and extensive bedding-parallel flow along open fractures (#3). Extraction times were 28 days, 7 days and 3 days, for samples #1, #2 and #3, respectively. Sequential series of extracts from the samples were analyzed using gas chromatography. For comparison, hydrocarbon compositions were also determined on bulk extracts of powdered original sister-sample material and the residues after flow-through experiments. The mobilities of hydrocarbons are controlled by the flow direction and fracture intensity and orientations. For sample #1, DCM flow-through extraction yielded mostly hydrocarbons associated with matrix kerogen. This flow-extracted bitumen was found to be much heavier than that extracted from the other two samples, and to have a lower mobility. The hydrocarbons extracted from the sample #2 were the lightest. For sample #3, containing micro-fractures along the bedding planes, the extraction process was apparently very effective, not only dissolving HC from the fractures but also some HC from the kerogen. The characteristic hydrocarbon compositions of the samples were essentially retained in all extracts, although lighter hydrocarbons (

This article argues that the oil industry is unlikely to return to the pre-2014 status quo as two profound shifts in technology and markets are dramatically changing the longer-term outlook for the oil industry. In the short term, traditional producers will feel persistent pressure from the shale revolution, a disruptive technology that has altered the cost curve and elasticity of oil supply. In the medium term, the industry must confront a structural slowdown and eventual peak in demand owing to innovation and evolving consumer preferences, related in part to concerns over climate change. Together, these shifts reflect a new energy order in which oil is no longer an exhaustible resource, new trading patterns emerge and oil prices exhibit greater short-term volatility amid a long-term declining trend. These new rules of the game force us to reconsider some of the theories and concepts of the international political economy of oil. We flag three key political effects from these market shifts: first, key oil-producing states face economic and political turmoil; second, OPEC cannot influence the price of oil in the long term by cutting output; and third, power is redistributed in the international system. [ABSTRACT FROM AUTHOR]

Currently there are two different industrial shale oil production processes utilized in Estonia called Galoter and Kiviter. It is known that the composition of pyrolytic water from these processes is different. The most emphasized difference lies in the concentration of phenols. However, the general composition of the water has not been very deeply investigated. Therefore, the purpose of this paper was to study the pyrolytic water from solid heat carrier technology (SHC). The pyrolytic water from the SHC process was subjected to headspace gas chromatography-mass spectrometry (GC-MS) analysis for the identification of organic compounds and to inductively coupled plasma mass spectrometry (ICP-MS) analysis for the identification of trace elements. The parameters generally used to describe wastewater - biochemical oxygen demand (BOD7), chemical oxygen demand (CODCr), suspended solids, dry residue, total organic carbon (TOC), pH, oil products, conductivity, amounts of phosphorus, nitrogen and sulphur -, were also measured. The analysed water contained surprisingly high amounts of sulphur and nitrogen, 0.03% and 0.24%, respectively. It was found that the water did not contain any significant amounts of toxic metals and it exhibited good biodegradability. [ABSTRACT FROM AUTHOR]

Considering Nigeria as an oil dependent country, fluctuations in oil prices as a result of policy competition between OPEC and oil shale producing countries (such as the United States and Canada) in recent years has posed an impediment on the current account balances of Nigeria. This study investigates the relationship between oil price fluctuations and the current account balances in Nigeria. The study used a time series data sample from 1977 to 2015. The Autoregressive Distributed Lag (ARDL) was used to estimate the relationship between the current account and oil price fluctuations in the short-run and long-run. It was argued from the findings that in the short-run, the oil price had a positive but insignificant impact on the current account balances, while in the long-run, it impacted negatively, but was found to be a significant determinant of current account balances in the economy. Other variables such as population growth (POP), gross domestic product (GDP) and trade (T) had an insignificant relationship with the current account balances in the short-run, while in the long-run, only GDP and oil price (OP) were found to be significant determinants of the current account balances in the economy. The study, therefore, concludes that better performances of the current account balance in the Nigerian economy are a function of the stability in the oil price. From the findings, it was recommended that the economy should be tailored towards mitigating the shocks in oil price through considering alternative means of trade. [ABSTRACT FROM AUTHOR]

The generative potential of kerogenous shale sequences in the Caucasus Maykopian series, the southern part of European Russia, is evaluated. The Khadum and Batalpashin sediments in the Eastern and Central Fore-Caucasus include three types of kerogen: I, II and III. The Khadum sediments are dominated by a more "noble" type II kerogen, mixed humic-sapropelic organic matter (OM). The Maykopian series may be attributed to the category of "rich" and "very rich" ("outstanding") oil source rocks. The maturity extent of the subject sediments within the region varies between the grades of protokatagenesis (maximum pyrolysis temperature (Tmax) = 390 °C) and MC4 (Tmax = 471 °C). Based on the pyrolytic studies, the Khadum and Batalpashin sediments are distinct from other pelitic rocks in rather high generative potential values. The average value of the total generative potential (S1 + S2) in the studied samples from the Khadum and Batalpashin Formations is 4.83 mg HC/g rock. The quantitative estimate of the hydrocarbon generative potential of the Khadum and Batalpashin sediments in this region was conducted for the first time. The total initial generative hydrocarbon potential of the sediments is 133.4 BT, being 92.7 BT for the Khadum Formation, and 40.7 BT for the Batalpashin Formation. [ABSTRACT FROM AUTHOR]

The pyrolysis of oil shale is a complex process including a myriad of chemical reactions. A widely approved understanding suggests a two-step decomposition process for oil shale pyrolysis, considering bitumen as the intermediate product. In this study, intermediates derived from various pyrolysis conditions are comprehensively studied by FTIR, GC, GC-MS and NMR methods to understand the pyrolysis mechanism of oil shale and composition feature of intermediate. The pyrolysis of oil shale is a dynamic process, and the results show that the intermediate is continuously generated before 400 °C, accompanying with the formation of final products from both intermediate and kerogen. The maximum yield of intermediates is presented at the fastest oil-producing temperature range (375 °C in this study). Carbon chains in intermediate become short with the increase in temperature. Most components in pyrolysis intermediate are long straight aliphatic chains; thus, intermediate is much heavier than shale oil. Further reactions make intermediate convert into shale oil product. Aliphatic hydrocarbons occupied the biggest proportion over 86% at 375 °C, mainly in the form of straight-chain alkanes. A few parts of aromatic fragments with small ring numbers will also transfer into intermediate. The heteroatom-containing compounds are mainly alcohols, ketones, amides and halohydrocarbons. High aromaticity in shale oil at high temperatures can be attributed to the condensation reaction of abundant aliphatic hydrocarbons in intermediate. During the conversion process from intermediate to final products, the generating capacity of oil is evidently higher than that of gas. [ABSTRACT FROM AUTHOR]

The hydroconversion of high-sulfur oil shale in the presence of natural mineral matrices: shale ash, sandstone, and clay has been investigated. It has been shown that mineral matrices containing clays and iron exhibit catalytic activity during the hydroconversion of oil shales. Due to this activity, a significant reduction in the sulfur and nitrogen content and an increase in the amount of light fractions in the resulting synthetic oil are achieved. [ABSTRACT FROM AUTHOR]

The Permian Basin is being transformed by the "shale revolution" from a major conventional play to the world's largest unconventional play, but water management is critical in this semiarid region. Here we explore evolving issues associated with produced water (PW) management and hydraulic fracturing water demands based on detailed well-by-well analyses. Our results show that although conventional wells produce ~13 times more water than oil (PW to oil ratio, PWOR = 13), this produced water has been mostly injected back into pressure-depleted oil-producing reservoirs for enhanced oil recovery. Unconventional horizontal wells use large volumes of water for hydraulic fracturing that increased by a factor of ~10-16 per well and ~7-10 if normalized by lateral well length (2008-2015). Although unconventional wells have a much lower PWOR of 3 versus 13 from conventional wells, this PW cannot be reinjected into the shale reservoirs but is disposed into nonproducing geologic intervals that could result in overpressuring and induced seismicity. The potential for PW reuse from unconventional wells is high because PW volumes can support hydraulic fracturing water demand based on 2014 data. Reuse of PW with minimal treatment (clean brine) can partially mitigate PW injection concerns while reducing water demand for hydraulic fracturing. [ABSTRACT FROM AUTHOR]

Conspectus Over the past decade, the United States has become a world leader in natural gas production, thanks in part to a large-fold increase in recovery from unconventional resources, i.e., shale rock and tight oil reservoirs. In an attempt to help mitigate climate change, these depleted formations are being considered for their long-term CO2 storage potential. Because of the variability in mineral and structural composition from one formation to the next (even within the same region), it is imperative to understand the adsorption behavior of CH4 and CO2 in the context of specific conditions and pore surface chemistry, i.e., relative total organic content (TOC), clay, and surface functionality. This study examines two Eagle Ford shale samples, both recovered from shale that was extracted at depths of approximately 3800 m and having low clay content (i.e., less than 5%) and similar mineral compositions but distinct TOCs (i.e., 2% and 5%, respectively). Experimentally validated models of kerogen were used to the estimate CH4 and CO2 adsorption capacities. The pore size distributions modeled were derived from low-pressure adsorption isotherm data using CO2 and N2 as probe gases for micropores and mesopores, respectively. Given the presence of water in these natural systems, the role of surface chemistry on modeled kerogen pore surfaces was investigated. Several functional groups associated with surface-dissociated water were considered. Pressure conditions from 10 to 50 bar were investigated using grand canonical Monte Carlo simulations along with typical outgassing temperatures used in many shale characterization and adsorption studies (i.e., 60 and 250 °C). Both CO2 and N2 were used as probe gases to determine the total pore volume available for gas adsorption spanning pore diameters ranging from 0.3 to 30 nm. The impacts of surface chemistry, outgassing temperature, and the inclusion of nanopores with diameters of less than 1.5 nm were determined for applications of CH4 and CO2 storage from samples of the gas-producing region of the Eagle Ford Shale. At 50 bar and temperatures of 60 and 250 °C, CH4 adsorption increased across all surface chemistries considered by 60% and 2-fold, respectively. In the case of CO2, the surface chemistry played a role at both 10 and 50 bar. For instance, at temperatures of 60 and 250 °C, CO2 adsorption increased across all surface chemistries by 6-fold and just over 2-fold, respectively. It was also found that at both 10 and 50 bar, if too low an outgassing temperature is used, this may lead to a 2-fold underestimation of gas in place. Finally, neglecting to include pores with diameters of less than 1.5 nm has the potential to underestimate pore volume by up to 28%. Taking into consideration these aspects of kerogen and shale characterization in general will lead to improvements in estimating the CH4 and CO2 storage potential of gas shales. [ABSTRACT FROM AUTHOR]

The objective of this paper is to compare the economic effects of innovation in an unconventional oil industry, based on Estonian and Canadian experiences with oil shale and oil sands, respectively. Both unconventional oil resources face similar challenges and need to resolve these through innovation. Based on empirical evidence, this paper concludes that innovation is a key mechanism of increasing efficiencies and triggering investments. Investments themselves, due to their nature, represent the best measure of the economic effect of cumulative innovation in the unconventional hydrocarbons industry. The paper proceeds in the following manner. First, we will briefly review the relevant literature and identify definitions of innovation and its impact on economic growth. In the second part, we will point out the effects of innovation in the energy industry on economic growth, and the uniqueness of energy innovation. Then we will present data on public and private R&D expenditure in the oil sands industry in Canada, as well as evidence of the results and economic effect comparatively to the R&D effort in Estonian oil shale industry. Lastly, we will draw conclusions by discussing our findings. The results are relevant to indicate R&D expenditure necessary to sustain investments and economic effects of developing unconventional hydrocarbon mineral resources. [ABSTRACT FROM AUTHOR]

A combined technological scheme for purification of undiluted high-strength wastewater produced in the shale oil industry was proposed. The initial values of chemical oxygen demand (COD), biological oxygen demand (BOD7) and phenols in the studied pyrogenic wastewater samples were up to 45, 35 and 1 g/L, respectively. Furthermore, the wastewater had a high toxicity to indicator organism Daphnia Magna (EC50 = 0.34%) and caused inhibition of oxygen uptake rate (IC50 = 3.4%) and nitrification rate (IC50 = 0.7%) in activated sludge treatment. The combination of air stripping, coagulation-flocculation, batch distillation, activated sludge and the Fenton oxidation processes reduced all measured parameters more than 95%. Consequently, a treatment scheme applicable to pyrogenic wastewater was developed. [ABSTRACT FROM AUTHOR]

Based on the results of the National Oil Shale Resource Evaluation in China conducted from 2003 to 2006, and combined with the new exploration progress in recent years, the characteristics and resource potential of oil shale in China have been systematically studied in this paper. Oil shale resources in China are abundant, with deposits mainly found in the continental environment and, secondarily, in marine-continental facies. The color of oil shale is black to grayish black, black to gray brown or gray to dark gray. In general, the darker the color, the higher the quality of oil shale. The most common minerals in oil shale are clay minerals, quartz and feldspars. The concentration of organic carbon in Chinese oil shale is high, between 7.48 and 38.02%. By organic genetic type, oil shale can be divided into sapropelic, humosapropelic and saprohumic oil shale. Oil shale used for industrial purposes has a medium to high oil yield and high ash content. Oil shale resources in China are mainly concentrated in 20 provinces and autonomous regions, 50 basins and 83 petroliferous shale areas. Total oil shale resources are estimated at approximately 978 billion tons, i.e. about 61 billion tons of in-place shale oil, mainly distributed throughout eastern and central China and the Qinghai-Tibet Region in western China. This paper outlines the distribution of oil shale deposits in China with respect to depositional basin type, and oil shale age and grade. Oil shale in China was deposited mainly in extensional and intra-plate basins during the Mesozoic and the Cenozoic. The size of the basins diminishes from older to younger deposits. Oil shale resources that yield shale oil more than 5% by weight account for about 72% of the rock's total resources in the country. [ABSTRACT FROM AUTHOR]

This paper explores the relationship between men and mining technology in an Estonian oil shale mine. It traces the linear time of socialism and postsocialism, arguing that for Estonian miners, the end of socialism might not have been as radical of a change as changing the mining technology in early 2000s. The introduction of the new technology changed the nature and perception of miners’ work, as well as the opportunities of controlling the everyday tempo of work. The way miners talk about new technology (novaia tekhnika) opens a window for exploring the different temporalities of socialism and capitalism. It allows seeing the way the time, through the state and the market, shapes small time of the everyday, the tempo of and rhythm of work. The wider changes from socialism to neoliberal capitalism which alter workplace relations, and create new class structures, are most acutely experienced at the nexus where new technology changes the rhythm and pace of work, the bodily activity of production which Bourdieu calls tempo. Furthermore, the introduction of new technology has implications to the job security and health of miners. [ABSTRACT FROM PUBLISHER]

Compared with the petrochemical industry, oil shale refinery industry is still relatively backward and has many shortcomings, such as poor quality of shale oil, inefficient utilization of retorting gas, and the unsatisfactory economic performance. In the situation of the low oil price, many oil shale refinery plants are forced to stop or cut production. Thus, oil shale industry is facing a severe problem. How to relieve monetary loss or turn it into profits? This paper proposes three integrated oil shale refinery processes: an integrated with hydrogen production from retorting gas, an integrated with hydrogenation of shale oil, and an integrated with hydrogen production and oil hydrogenation. The techno-economic performance of the three different processes is conducted and compared with that of a conventional oil shale process. Results show the exergy destruction ratio of the oil shale process integrated with hydrogen production from retorting gas is the least, 41.6%, followed by the oil shale process integrated with hydrogen production and oil hydrogenation, 45.9%. Furthermore, these two proposed processes have the best economic performance. Especially they can turn losses of the conventional oil shale process into profits at the situation of low oil price. The oil shale process integrated with hydrogen production from retorting gas is recommended to the oil shale plants which use the oil shale with oil content lower than 12.9%, while the plants using oil shale with oil content higher than 12.9% are better to select the oil shale process integrated with hydrogen production and oil hydrogenation. [ABSTRACT FROM AUTHOR]

Engaging with nascent scholarly efforts to foreground the ‘geo’ of geopolitics, this article examines how certain low-quality geological substances are constituted as strategic, ‘unconventional’ fossil fuel resources, the exploitation of which is deemed indispensable for energy security reasons. Based on a detailed study of oil shale exploitation in Estonia, the paper specifically analyses the politics of knowledge that enable such carbon-intensive and energy-inefficient industries to perpetuate at the national level and, moreover, subvert the neoliberal imperatives of energy sector deregulation and decarbonisation arising from EU policies. This analysis leads to two key arguments. At one level, the Estonian case evidences and contextualises the growing recognition that ‘energy security’ represents a multifaceted and dynamic construct as it highlights, in particular, the contingency of expert knowledge in its conceptualisation and performance. What counts as energy security is in this case articulated via shifting and contested modes of knowledge-making, whereby state- and market-led modes of energy governance are continuously renegotiated. At another level, however, the politics of knowledge is explained here as exercised through contending ontologies of the fossil fuel resource that pivots security claims, or ‘geo-logics’, which has multiplying effects on resource materiality. [ABSTRACT FROM PUBLISHER]

The objective of this paper is to elucidate the sustainability of Estonian shale oil industry until the year 2030 in terms of the full cycle breakeven cost of oil. The full cycle cost is rapidly increasing due to increasing necessary capital expenditure, increased national taxation and the European Union (EU) carbon (C) emissions abatement policies. There is a fair amount of uncertainty about all three components, which makes scenario analysis an appropriate tool to estimate the survivability of Estonian shale oil industry scenarios in the next 15 years. Past economic performance alone is not a proper guide for future in case of Estonian oil shale industry. However, heavy investments have been made in the industry since 2011 and several hundred million euros are being invested or planned to invest in the replacement of old capacity and raising new oil production capacity. Analysis shows that, indeed, in certain scenarios the shale oil breakeven price is at the highest end of global crude oil production projects, thus raising questions of the industry’s survivability in case of multiyear sustained global oil prices below 90 USD/bbl. Conclusions of the study are relevant to analyzing the full cycle costs of other promising global shale oil projects. [ABSTRACT FROM AUTHOR]

The aim of this study is trying to reveal the thermal characteristics and kinetics of oil shale, municipal solid waste and their blends in the combustion process which are needed for efficient utilization. The combustion experiment is carried out in a thermogravimetric simultaneous thermal analyzer, where the temperature ranged from 110 °C to 900 °C at three different heating rates as 10 °C/min, 20 °C/min and 30 °C/min. Their kinetics were studied by Ozawa–Flynn–Wall and Friedmen methods. According to the data analysis, combustion characteristic index increased progressively with the increase of the proportion of municipal solid waste. And it’s suggested that there was certain interaction in the combustion process of oil shale and municipal solid waste. The average activation energy of the blends reached the minimum value, 177.7927 kJ/mol by Ozawa–Flynn–Wall method and 167.4234 kJ/mol by Friedmen method, when the proportion of MSW was 70%. [ABSTRACT FROM AUTHOR]

Estonia is a relatively small country with a limited supply of indigenous energy resources mainly consisting of oil shale, wood, and peat. Estonia is also the only country in Europe with a dominant electricity production by burning oil shale. Around 90% of the overall electric energy production in Estonia comes from the Narva Power Plants. This presents great challenges and problems due to massive emissions of greenhouse gases into the atmosphere as well as radiological impact on the environment. Therefore, the current energy supply strategy can be considered hazardous and an unpopular choice for future energy system planning. In this article, we analyze the current energy policy as well as inclusion of new strategies to produce electricity for Estonia for a target year of 2035. We use a computer model Model for Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE) to provide optimization and aim in helping the policymakers in the Estonian decision making process. We also add a specific case in the MESSAGE model to examine the ability of the current electricity supply strategy to handle climate related shocks with a special focus on cold weather in two plausible cases; single cold winter and prolonged cold winter. Results indicate that unexpected demand shocks may cause serious losses in gross domestic product (GDP). Therefore, the authors come to the conclusion that extra capacity is highly recommendable for a number of reasons. We also find that nuclear power becomes economically preferable to oil shale with a CO2 tax of €20/t. Yet moving toward nuclear or other low CO2 alternatives presents certain challenges. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 469-478, 2016 [ABSTRACT FROM AUTHOR]

The conversion of black oil in hydrogen (hydroconversion) and nitrogen (pyrolysis) media was studied. The influence of the hydrogen pressure and temperature of the hydrotreating of black oil on the yield and properties of the resulting liquid hydrocarbons was examined. Hydrogen actively participates in the conversion of kerogen (major organic component of black oil), which leads to an increase in the conversion of the organic matter, to an increase in the yield of liquid hydrocarbon products, and to improvement of their quality, compared to pyrolysis. The highest conversion of organic carbon (91.7%) and the maximal yield of liquid hydrocarbons (30.7 wt %) were reached in a hydrogen medium at a pressure of 10.0 MPa and a temperature of 400°C. [ABSTRACT FROM AUTHOR]

Products of thermal cracking of kerogen of Lower-Middle Cambrian oil shale are studied by modern instrumental analytical methods (FTIR, gas chromatography, mass spectrometry, etc.). The analyses demonstrate that the geopolymer kerogen matrix inherited fragments of lipids synthesized by living organisms, including aliphatic fat acids, both free or bounded into glycerol esters, i.e., animal or vegetable fats. It is shown that vegetable pigments (carotenes and xanthophylls) play a crucial role in the formation of monocyclic structures (including molecular alkylbenzene, alkylphenol, and phenylalkane fragments) in kerogen. Since the studied kerogen is rich in esters, it is worth performing alkaline hydrolysis of its macromolecules (ester saponification) before their thermolysis, which inevitably distorts the initial structure of molecular skeletons. [ABSTRACT FROM AUTHOR]

In order to characterise current and historical pattern of heavy metal (HM) pollution in Estonia, this article will compare the concentrations and stocks of Cd, Cr, Cu, Ni, Pb and Zn represented in current deposition (data from 18 local precipitation stations) with natural media of three different ages: 1–3-year-old moss carpet (ICP Vegetation moss survey data from 99 open area plots), 3–5-year-old litter layer, and several-decades-old organic layer (mor humus) of coniferous forest, in mostly podzolic soils (ICP Forest soil survey data, 75 stands). Objectives of this study are (1) to assess differences in HM retention and accumulation in various aged media of coniferous stands (2) to estimate territorial differences in current HM distribution and previously accumulated concentrations and stores of HM (3) to compare territorial distribution of HM concentration in Estonia between five different regions: N-W; N-E; S-W; S-E and Western insular region, whereas the local oil shale industry in N-E part of Estonia has been the main source of HM pollution over a long period of time and therefore may have an effect on HM regional distribution. Comparing the studied media, three types of HM retention patterns were detected: (1) for Cu, Ni, Cr (2) for Cd, Pb, (3) for Zn. The mean current level of HM deposition in Estonia is low comparison to previous decades, especially the 1980s. The effect of the previously significantly higher exposure of HM emissions and deposition is preserved in older part of soil organics (OF), where the highest stocks and concentrations of HMs (with the exception of Zn) are currently found. The HM proportions in fly ash of oil shale and in OF layer of soil were very similar with regards to Ni and Cr—indicating their origin from the oil shale industry in the N-E region. According to spatial distribution analysis, the greatest accumulated storages of Ni and Cr in OF layer of coniferous forest soils are characteristic to S-W Estonia. [ABSTRACT FROM AUTHOR]

In the well-known continental Songliao Basin, the oil shale successions of the Cretaceous Qingshankou Formation are excellent source rocks for oil. The oil shale layers with high TOC (total organic carbon) contents developed at the bottom of the formation. They are divided into the lower oil shale (TOC up to 18.3%) and the upper oil shale layer (TOC up to 14.4%). The oil shale layers and accompanying mudstones are investigated by high resolution analyses of drill cores by pyrolysis, organic petrology, organic and inorganic geochemistry. The results demonstrate the predominance of type-I kerogen derived from algal-microbial mats (i.e. lamalginite). However, increased proportions of plant-derived organic matter are indicated by Rock-Eval parameters and the presence of vitrinite in the upper oil shale. As evidenced from lower concentrations of hopanes, higher sinking rates of organic matter (OM) are suggested to have been responsible for a lower extent of microbial degradation during accumulation of the lower oil shale unit. The environmental conditions are characterized by anoxic saline bottom water overlain by an extended zone of freshwater, favorable for OM production and preservation. Under these preconditions, oil shale thickness and quality are governed by primary productivity, related to accommodation space and nutrient supply. Redox conditions within the water column are the key factor controlling organic matter preservation. [ABSTRACT FROM AUTHOR]

Increased shale gas and shale oil production in the USA will affect global geopolitics and national security considerations. An influx of Qatari LNG into Europe and Asia, which is diverted from the USA, erodes the tremendous market share held by the Russian gas company Gazprom and significantly reduces its pricing power. The USA did not begin to import the quantities of LNG from countries like Qatar and Trinidad and Tobago. Those quantities have instead been redirected to other markets, including Europe. As part of the impact of the US shale revolution, Russian energy control over Europe will be greatly reduced. Russia's power over the region will also be reduced. Russia has earned from US$42 billion to US$60 billion per year from selling gas to Europe. Fewer exports and lower prices will cut those revenues. Given the importance of oil and gas companies to Russia's economics, it is urgent for Moscow to restrict Central Asian production and infrastructure to mainly or even exclusively Russian channels lest Russian oil and gas become less competitive due to its own high cost and wasteful monopolistic structure and dilapidated infrastructure. [ABSTRACT FROM AUTHOR]

Semi-coke is classified as an environmentally harmful residue of oil shale industry due to its toxic components: several organic and inorganic compounds – oil products, asphaltenes, phenols, PAHs, sulphuric compounds. The aim of the present work was to compare the abundances and species compositions of soil invertebrate assemblages (Collembola, Lumbricidae, Araneae, Myriapoda, Coleoptera) in the artificial substrate from vegetated and bare residue sites of semi-coke heaps of Estonian oil shale industry. Invertebrate communities in semi-coke heaps were studied at three heights of each heap slope; all sampling points in the heaps were divided into four groups based on plant cover. The authors concluded that the communities of micro- and macroarthropods and earthworms in oil-shale processing waste heaps were formed under certain conditions – a high pH and extremely low moisture. The presence of several invertebrate groups (springtails, earthworms, epigeic predators, etc.) and soil communities can be used for monitoring the success in restoration. [ABSTRACT FROM AUTHOR]

The author discusses the decline of the brent crude oil price to around 50 $/barrel (bbl) to the production of shale oil from oil shale in Estonia.

The article discusses relations between the leadership of the First Nations communities in British Columbia with the provincial government. It explores the consultation agreements established between the Oil and Gas Commission with Treaty 8 First Nations in regarding the development of the shale oil and liquified natural gas industries on the lands of the First Nations.

The reserves of oil shale are over 5 times as many as the current natural proven recoverable oil reserves in the world. It has huge potential but it is hard to obtain economic efficiency because of its low oil length and exploration difficulty. This research combines theory and experiment, evaluates the exploitation of in-situ heating of oil shale with injection fluid, which have the characteristics of high oil length, large productivity and short production cycle. For the oil shale layer with high oil length (>18%), the oil price shall at least reach 105 $/bbl (18% oil length) to maintain 10% of the internal rate of return; for the oil shale with low oil length (3.5–18%), the oil price shall at least reach 377 $/bbl (5% oil length) to maintain 10% of the internal rate of return. At present, only the oil shale with high oil length (>18%) can be exploited for in-situ heating of oil shale with injection fluid in China. [ABSTRACT FROM AUTHOR]

The biomass allocation, as well as leaf and short root morphological parameters in young (1-7-year-old) black alder (Alnus glutinosa (L.) Gaertn.), silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) plantations on the oil shale post-mining area were investigated with the aim to analyze morphological adaptations of studied parameters in relation to tree species and stand age. The adaptive strategies of tree species in young plantations on the reclaimed stony and alkaline mining area were different. Scots pine allocated more biomass into leaves and fine roots while black alder and silver birch into stems and coarse roots. The black alder leaves were heavier and with larger area, but thinner than those of silver birch. Different strategies of short root morphological adaptations were observed in coniferous and deciduous tree species on the oil shale post-mining area. Deciduous species were found to have higher short root specific root area and specific root length values, and lower short root tissue density and diameter values compared to coniferous species such as Scots pine. An extensive building of the fine root system was inherent to Scots pine, whereas deciduous trees improved mineral nutrition more by morphological adaptations of fine roots. [ABSTRACT FROM AUTHOR]

Oxy-fuel combustion is considered as one of the promising carbon capture and storage (CCS) technologies for coal-fired boilers. In oxy-fuel combustion, the combustion gases are oxygen and the recirculating flue gas, and the main components of the combustion gas are O2, CO2 and H2O [1]. The paper presents the results of the calculation of the flue gas amount during combustion of oil shale using oxy-fuel technology in a circulated fluidized bed (CFB) mode. The calculations were performed for different oil shale heating values and different recycled flue gas (RFG) ratios. Oxy-fuel combustion with flue gas recycling was found to enable the decrease of the extent of carbonate minerals decomposition (ECD), thereby increasing the amount of heat released per 1 kg of fuel. To minimize ECD, the recycled flue gas ratio should be maintained at a level higher than 0.7. This condition allows an increase of the partial pressure of CO2 over the equilibrium state line of calcite decomposition reaction at the bed temperature. The decrease of ECD was observed up to kCO2-min = 0.28. The decrease of kCO2 leads to an additional increase in the amount of heat released during oil shale combustion per 1 kg and, depending on the mean lower heating value (LHV), the heat can be increased up to 0.34 MJ/kg. A comparison with the bituminous and anthracite coals revealed that the specific emission of CO2 per input fuel energy for oil shale is expected to be even smaller compared with those of the considered coals. [ABSTRACT FROM AUTHOR]

The article discusses the essential of oil shale, a fine-grained sedimentary rock that contains organic matter yielding economic amounts of oil and combustible gas during destructive distillation. It states the large number of deposits worldwide and the determination on its potential as reserves including Australia, Jordan and the U.S. An overview of the uses and the geological explorations of the mineral resources are also mentioned.

Oil shale is considered the most important natural resource of Estonia and its role in energy production and chemical industry has been pointed out in numerous papers. But there are no special publications about the history of the Estonian oil shale industry in English. This article tries to fulfil the gap relying on numerous archival documents and literature sources which have remained out of the attention of scientists up till now. It follows from the article that without the studies carried out by Russian researchers in 1916-1920 the Estonian oil shale industry may not have been born. Using the results of Russian investigators, the Estonians hoped to set up their own oil shale industry applying Scottish experience. This hope failed, however, and thus the Estonians had to elaborate their own methods for the development of oil shale chemistry. [ABSTRACT FROM AUTHOR]