Natural Bitumen Deposits Research Articles

Fish assemblage monitoring in Alberta’s Ells River: Baseline fish and habitat variability prior to major development

The collection of sentinel fish species for Environmental Effects Monitoring (EEM) has provided ancillary fish assemblage surveys on several tributaries in the Athabasca Oil Sands Region (AOSR) of Alberta, Canada over the last decade. Using available, comparable data we investigated baseline fish assemblage variability along the Ells River, a tributary of the Athabasca River experiencing increasing proximity to natural bitumen deposits and proposed mining development as it approaches confluence with the mainstem Athabasca. Transect-based electrofishing data from four sites surveyed in September 2013, 2014 and 2018 showed significant spatiotemporal variability in assemblages, where spatial variability was greatest in 2013 and temporal variability was observed in assemblages both upstream (2013–2014) and downstream (2014–2018) of proposed development. Habitat assessments in 2018 revealed significant relationships among pH, algae cover and site slope with fish assemblages of the same year. Due to the complementary nature of assemblage surveys, data challenges (changing methodologies, sampling effort, and limited ancillary physiochemical data) have presented limitations to the multivariate approach applied in the study. Moving forward, employing consistent methods for fish collections and fine-scale habitat assessments will improve the ability to correlate assemblage variability with changes in the physical environment. Ultimately, this will aid in developing potential triggers of change that may be attributed to or confound adjacent, expanding Oil Sands activities. These findings will also inform monitoring programs on the use of fish assemblages as indicators of change, potentially providing an alternative to existing biomonitoring approaches in small streams with small fish populations.

Geoecological problems of development of heavy oil and natural bitumen deposits

Geoecological problems of development of heavy oil and natural bitumen deposits

Trace metals as indicators of tree rooting in bituminous soils

AbstractIn some reclamation practices, following bitumen mining in the Canadian Boreal forest, overburden containing low concentrations of hydrocarbons (<8% of bulk soil volume) is buried under suitable soils. Residual hydrocarbons may influence the growth of trees used in afforestation of reclaimed sites, thus determining whether roots interact with buried bitumen is a key to predicting reclamation success. As the organic fraction of bitumen is enriched in vanadium, nickel, molybdenum, and rhenium, dendrochemistry may be a method to determine whether tree roots are interacting with bitumen without disturbing soils. We analyzed trace concentrations of these metals in soil, soil pore water, and tree cores of Pinus banksiana growing on natural bitumen deposits and sites free of bitumen. If roots are present within bitumen and passively uptake trace metals during water transport and wood growth, metals enriched in bitumen should be present in higher concentrations in the woody tissue of trees growing in bituminous soils compared to trees growing in bitumen‐free soils. Concentrations of nickel in trees growing on shallow bitumen deposits were approximately 3× higher than those growing in bitumen‐free soils. The concentration of vanadium (1.33 μg kg−1 in younger wood and 3.21 μg kg−1 in older wood) was also elevated in trees on bituminous sites, though not significantly. Molybdenum concentrations decreased by ~25% in trees growing on bituminous sites, likely an outcome of soil pH. This research supports the use of dendrochemistry to investigate, and potentially monitor, tree rooting at depth in substrates with signature metals.

The influence of lithofacies features of the Permian natural bitumen-saturated reservoir rocks on groundwater formation conditions

The reservoirs rocks of natural bitumen deposits of the Lower Permian system and the Kazanian stage of the Tatarstan territory are considered. The relationship of groundwater composition in bitumen reservoirs with lithologic features of water-saturated rocks is shown. Rocks compositions contribute to formation of three water classes in oil deposits: hydrocarbonate, sulfate and chloride. Hydrocarbonate waters lie over erosion downcutting of rivers in the most elevated territory part. Their origin is associated with hydrolysis and carbon-dioxide leaching of the Permian terrigenous rocks. Inland waters of hydrocarbonate-sodium (soda) composition of bitumen deposits are located above local drainage basis. They are formed as a result of sulfate reduction processes in deposits. The inland waters of sulfate composition of calcium and sodium groups are characteristic of deposits located below the drainage basis. Their origin is associated with dissolution of gypsum and anhydrites, as well as with ion exchange reactions between the calcium of the solution and the sodium which absorbed by rock complex. Chloride waters associated within the eastern side of the Melekess Depression, where there is an active hydrodynamic relationship between the Permian system aquifers and chloride-calcium salt brines of the Carboniferous rocks. The nature of the distribution and presence of aquifers in deposits is determined by the lithological features of reservoir formation.

Improvement of the bitumen extraction technology from bituminous sand deposits

Today considerable experience in the development of tar sands is accumulated. However, well-known mining technologies do not cover the entire depth range of natural bitumen deposits. In addition, there are significant energy-intensive technologies and negative environmental impacts. In view of this, the purpose of this work is to improve the method of extracting natural bitumen in site for a deposit interval of 75 – 200 m and to substantiate the basic technological scheme of this method. The proposed method of extracting bitumen from poorly cemented reservoirs in the depth range of 50 – 400 m provides: creation of artificial mine working; the transfer of the rock into the water mixture composition under the action of high pressure jets of a heated mixture of water, a hydrocarbon solvent and a flotation agent; separation from the rock and concentration of bitumen in the production as a result of its heating, dissolution and flotation; selection of depleted bitum slurry from the mine working by gas lift method. The proposed method of extracting bitumen is the transfer of the rock at the site of its occurrence to the suspension condition on the excavation created by the hydraulic production method, separation and concentration of bitumen by dissolving it with a heated hydrocarbon solvent and a flotation agent (hydrocarbon reagents), and extraction in the composition of depleted rock slurry to the surface by the gas lift method. As the preliminary calculations show, the proposed method will allow the efficient extraction of bitumen and highly viscous oil from weakly cemented reservoirs in the depth range of 50 – 400 m. Also, the proposed technology creates the preconditions for the development of oil sands at a depth of 75 – 200 m since there is currently no effective technology for the interval. In addition, it can significantly reduce energy costs, environmental pollution and greenhouse gas emissions.

Problems of shale oil hydrocarbons, ultra-viscous oil reservoirs and natural bitumen deposits development in Tatarstan

The area of the Volga-Ural oil and gas basin belongs to the “old” oil and gas bearing regions. The most part of easily recoverable reserves of large and unique oil fields already have been developed within the area. Therefore, super-viscous oil reservoirs, natural bitumen deposits and shale hydrocarbons seized the attention of local petroleum geologists. Tatarstan is a classic example in that sense. The Republic of Tatarstan is a leader in the development of heavy oil resources, a leader in the degree of knowledge of natural bitumen accumulations, as well as a leader in technological readiness for their development. In the depths of Tatarstan, there are more than 450 fields of ultra-viscous oil and natural bitumen with reserves ranging from 2 to 7 billion tons of this type of hydrocarbons. However, their industrial development due to low profitability is slow. To solve the problem, it is necessary to search for and commercialize economically viable technologies for the production, transportation and processing of hydrocarbons, which take into account its features and do not require increased energy and other material costs. Therefore, the search for the right unconventional hydrocarbons production concept is an urgent problem of our time.

Development of natural bitumen (bituminous sands) deposits based on the technology of hydraulic mining by boreholes

The modern state and trends in the development of technologies for mining the heavy oil and native bitumen deposits have been analyzed. It has been set that presently known technologies for heavy oil and natural bitumen extraction do not cover the entire depths range of their occurrence. The main possibility of the development of heavy oil and natural bitumen deposits on the basis of technology by hydraulic mining by boreholes has been substantiated. The peculiarities of this technology are analyzed. The ways of its main elements adaptation for mining the natural bitumen from bituminous sands deposits are offered. The principal scheme has been substantiated for a method of mining the natural bitumen on the basis of hydraulic mining by boreholes. The thermodynamic processes occurring in the productive formation during its drilling with the simultaneous circulation of the heat-transfer medium have been analyzed. A mathematical model has been developed of the thermal penetration process into the productive formation for the time interval from the beginning the borehole drilling to the beginning the rock disintegration. Also, it has been solved the task of stationary mode in the borehole at the stage of its drilling.

The Sukhana Sedimentary Basin, Siberian Platform: Source Rock Characterization and Direct Evidence of Oil and Gas Presence

Abstract —Despite the known large natural bitumen accumulations and oil seeps in several kimberlite pipes along the periphery of the Sukhana sedimentary basin, interpreted as direct evidence of petroleum potential, the basin still remains one of the least studied (by geological and geophysical methods) regions of the Siberian Platform. The platform cover of the basin is composed by Riphean, Vendian, and Cambrian clastic (terrigenous) and carbonate deposits reaching 5.5–6 km in thickness in the central part of the basin. The hydrogeological specifics of the basin is largely governed by its location within the northern geocryological zone (Olenek cryoartesian basin) and is expressed as a continuous distribution of permafrost aggraded into the permafrost zone of unique thickness. Direct indicators of ore and gas presence are the East Anabar, Central Olenek, and Siligir–Markha fields of natural bitumen and oil shows in kimberlite pipes of the Daldyn–Alakit region (Udachnaya pipe). The bituminous-carbonate sediments of the Khatyspyt Formation (Vendian, Ediacaran) and the highly carbonaceous carbonate–siliceous–shaly sediments of the Kuonamka Formation (lower–middle Cambrian) are the Sukhana source rock complexes. The geochemically substantiated genetic relationship between the natural bitumen deposits of the East Anabar field and the organic matter of the Vendian Khatyspyt Formation makes it possible to estimate the area of the spread of the latter far to the west, beyond the axial part of the basin. Gammacerane, inherited from the organic matter of the Khatyspyt Formation and ranking as well-preserved and most characteristic biomarker of these bitumens, provides a compelling evidence of their consanguinity. The bitumen and oil of kimberlite pipes in the south of the basin, in the area of reefs of the Siligir–Markha bar, are similar in all geochemical criteria to oils of the Nepa–Botuobiya anteclise. In particular, in primary geochemical characteristics (12- and 13-monomethylalkanes, unique secosteranes, identical carbon isotope composition, etc.) the oils of the Udachnaya pipe are identical to the Irelyakh oils (oil field in the Mirnyi arch). No accumulations of oil or natural bitumen genetically related to the highly carbonaceous Kuonamka Formation have been found within the basin. At the same time, “intraformational” shows of viscous oil, solid bitumen, and allochthonous bitumen (bitumen extracted with chloroform) were documented directly in the sections of the formation, which makes the sedimentary basin a very attractive target for “shale oil” exploration. As for the regional assessment of the petroleum potential of the entire basin, its axial part (Sukhana depression) complicated by local uplifts is of the greatest interest. Both the Khatyspyt and Kuonamka Formations are widespread there, with the thermal maturity of their organic matter corresponding to the oil window. In addition, the regional reservoirs at the Vendian–Cambrian boundary have good petrophysical properties on both the western and the eastern flanks of the basin.

Natural Bitumens: Physicochemical Properties and Production Technologies

The physicochemical parameters and the extraction technologies of natural bitumens—solid or viscous natural materials that are the products of hypergenic, phase-migratory, contact-metamorphic, and other natural transformations of oil—were analyzed. The separation of bitumens is based on their physicochemical properties, the most important of which are solubility in chloroform, oil content, specific gravity, coking behavior, Mohs hardness, group composition, and consistency. It was shown that the physicochemical properties of natural bitumens and black and oil shales, their hydrocarbon composition, and the concentrations and ratios of their ore components depend on the initial organic matter, the litho-facial conditions of its burial, and the subsequent accumulation and destruction, that is, on the geological history of sedimentary basins. To improve the efficiency of further development of natural bitumen deposits, it was proposed to introduce a highly efficient integrated technology for developing hard-to-recover reserves, the most important elements of which are the application of thermal effects using various heat sources, horizontal drilling, and hydraulic fracturing.

Reservoir geology and effects on exploitation of natural bitumen deposits (Nigerian deposits as a case study)

Geological investigation have led to discovery of huge tar sand deposits within Afowo Formation of the Turonian–Maastrichtianage (95.9–66.0 Ma) in the Nigerian sector of the Eastern Dahomey Basin. This study aims at determining the feasibility of exploiting the major hydrocarbon resource steam assisted gravity drainage enhanced recovery technique. Samples from three core holes were dry sievied to determine the particle size distribution and their sections studied using a petrographic microscope. Clay mineral content was determined using X-ray diffraction scanning electron microscopy. The granulometric analysis shows the bituminous sediments to be generally fine grained and moderate to well sorted, and the grains are angular to subangular. Porosity ranges from 15.5 to 33.6 ɸ with average value of 26.4 ɸ, while permeability ranges from 270 to 4800 mD, with an average value of 4800 mD (very high) recorded for the sandstones. Petrographic study, scanning electron microscopy and X-ray diffractometry showed quartz as the dominant mineral component, with subordinate feldspar and other accessory minerals. The predominance of quartz is probably due to its mechanical stability. The low frequency of feldspar is attributable to its susceptibility to chemical breakdown and alteration, respectively, during transport and after deposition, with latter accounting for the observed secondary porosity. Kaolinite is the common clay mineral present in the oil sands and may not have sufficiently reduced the reservoir quality to negatively impacting enhanced recovery operation by steam assisted gravity drainage.

Geological criteria and geophysical methods of natural bitumen deposits preparation to the development

The article considers the provisions of the ontogenesis of the following factors in the formation of natural bitumen clusters in the Permian deposits of the Melekesskiy region: genetic, geodynamic, structural and hydrogeological.It is shown that tectonically weakened zones and zones of Neogene incisions development are fixed by high-precision gravimetry in the form of intense local minima of gravity. A favorable factor contributing to the "strengthening" of anomalous geophysical effects is the coincidence of the locations of these geological section heterogeneities in the plan.It is recommended at the stage of experimental-industrial operation a complex of geophysical methods for monitoring the processes of natural bitumen deposits development by means of secondary impact on the formation. High-precision magnetic, thermal and electrical prospecting in various modifications are used.

Characterization and determination of naphthenic acids species in oil sands process-affected water and groundwater from oil sands development area of Alberta, Canada

This work reports the monitoring and assessment of naphthenic acids (NAs) in oil sands process-affected water (OSPW), Pleistocene channel aquifer groundwater (PLCA), and oil sands basal aquifer groundwater (OSBA) from an active oil sands development in Alberta, Canada, using ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) analysis with internal standard (ISTD) and external standard (ESTD) calibration methods and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) for compositional analysis. PLCA was collected at 45–51 m depth and OSBA was collected at 67–144 m depth. Results of Ox−NA concentrations follow an order as OSPW > OSBA > PLCA, indicating that occurrences of NAs in OSBA were likely related to natural bitumen deposits instead of OSPW. Liquid-liquid extraction (LLE) was applied to avoid the matrix effect for the ESTD method. Reduced LLE efficiency accounted for the divergence of the ISTD and ESTD calibrated results for oxidized NAs. Principle component analysis results of O2 and O4 species could be employed for differentiation of water types, while classical NAs with C13−15 and Z (-4)−(-6) and aromatic O2−NAs with C16−18 and Z (-14)−(-16) could be measured as marker compounds to characterize water sources and potential temporal variations of samples, respectively. FTICR-MS results revealed that compositions of NA species varied greatly among OSPW, PLCA, and OSBA, because of NA transfer and transformation processes. This work contributed to the understanding of the concentration and composition of NAs in various types of water, and provided a useful combination of analytical and statistical tools for monitoring studies, in support of future safe discharge of treated OSPW.

Has Alberta Oil Sands Development Altered Delivery of Polycyclic Aromatic Compounds to the Peace-Athabasca Delta?

BackgroundThe extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north) is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstream ecosystems provided impetus for several recent expert-panel assessments regarding the societal and environmental consequences of this multi-billion-dollar industry. Deciphering relative contributions of natural versus industrial processes on downstream supply of polycyclic aromatic compounds (PACs) has been identified as a critical knowledge gap. But, this remains a formidable scientific challenge because loading from natural processes remains unknown. And, industrial activity occurs in the same locations as the natural bitumen deposits, which potentially confounds contemporary upstream-downstream comparisons of contaminant levels.Methods/Principal FindingsBased on analyses of lake sediment cores, we provide evidence that the Athabasca Delta has been a natural repository of PACs carried by the Athabasca River for at least the past two centuries. We detect no measureable increase in the concentration and proportion of river-transported bitumen-associated indicator PACs in sediments deposited in a flood-prone lake since onset of oil sands development. Results also reveal no evidence that industrial activity has contributed measurably to sedimentary concentration of PACs supplied by atmospheric transport.Conclusions/SignificanceFindings suggest that natural erosion of exposed bitumen in banks of the Athabasca River and its tributaries is a major process delivering PACs to the Athabasca Delta, and the spring freshet is a key period for contaminant mobilization and transport. This baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring programs for the lower Athabasca River watershed.

Ancient asphalt may have poisoned prehistoric Americans

Prehistoric cultures used natural bitumen deposits to improve their lives – but did their health suffer as a consequence?

Studies of carcinogenicity of bitumen fume in humans.

AbstractSince antiquity humans have used bitumen, either naturally occurring or derived from crude oil [Broome and Hobson, 1973], and it may have been the binding material described for bricks used in the construction of the Tower of Babel (Genesis 11, 3).Chemically, bitumen is a complex mixture of hydrocarbons consisting of both aliphatic and aromatic compounds, some of which bear nitrogen, oxygen, or sulfur functional groups [Broome and Hobson, 1973]. This material has been in widespread use since the industrial revolution. The first bituminous road was built in 1810 in Lyon, France. Large‐scale industrial use of bitumen began with the exploitation of natural bitumen deposits in Trinidad, with the first commercial shipment arriving in England in the 1840s. Bitumen's main use, in terms of volume, has been in paving, as a binder for inorganic fillers in asphalt mixes. According to conservative estimates, there are at present approximately 4000 asphalt mixing plants in western Europe. A typical mixing plant employs five to ten individuals. These plants produce approximately 275 million tons of hot and 10 million tons of cold asphalt annually. Asphalt mixes are applied to road surfaces by approximately 100,000 paving crewmen across western Europe. Other important uses of bitumen are in waterproofing and roofing. Thus, assessment of the health hazards of bitumen fumes may have far‐reaching industrial, economic, and public health implications.Of specific concern is the potential carcinogenicity of bitumen fume inhalation. In 1985 and 1987, the International Agency for Research on Cancer [IARC, 1985, 1987] evaluated extracts of steam‐refined and air‐refined bitumen carcinogenicity in experimental animals and classified them as possible human carcinogens (IARC Group 2B), while for undiluted bitumen, the evidence of carcinogenicity in humans was inadequate (IARC Group 3).Meta‐analysis identified and reveiwed the epidemiological studies informative of cancer hazard in asphalt workers [Partanen and Boffetta, 1994]. However, the aggregated data could not explicitly address effects of bitumen fumes. Agent‐specific exposure data were lacking, conjectured, or controversial, leaving open a number of questions with regard to the interpretation of the results. The aggregated results suggested an increased risk of cancers of the lung, (relative risk 1.8; 95% confidence interval 0.8‐1.0).The main uncertainty in the assessment of previous epidemiological data arises from the inability to exclude the possibility of confounding by concurrent use of both coal tar a recognized carcinogen, and bitumen by pavers, roofers, and waterproofers [IARC, 1985, 1987]. The voluntary discontinuation of coal tar use by the asphalt industry in western Europe during the past few decades presented an opportunity to discover whether it is likely that bitumen exposure per se is carcinogenic [Partanen et al., 1995]. To address this question, a historical cohort of asphalt workers was assembled by IARC in eight countries (Denmark, Finland, France, Germany, the Netherlands, Norway, Sweden, and Israel) in order to obtain diverse exposure profiles and a sufficient number of cases for the main health outcome of interest: lung cancer.Detailed results on the mortality of the workers included in the international study have been published in an IARC Internal Technical Report [Boffetta et al., 2001]. In this issue of the Journal, several papers report the key findings on cancer mortality [Boffetta et al., 2003a,b], which provide the most complete assessment of cancer hazards among workers exposed to bitumen fumes.It is a complex task to organize and conduct international occupational cohort studies. This project was a successful example of collaboration between academic research groups, public bodies, and industrial associations. Among other challenges, it overcame the Babel of multiple languages.