Oil Sands Extraction Research Articles

Tracking historical sources of polycyclic aromatic compounds (PACs) in dated lake sediment cores near in-situ bitumen operations of Cold Lake, Alberta

Most bitumen in the Alberta oil sands (Canada) is extracted by thermal in-situ recovery. Despite the widespread use of in-situ bitumen extraction, little information is available on the release of petroleum hydrocarbons by this method to adjacent land and water. Here we analyzed the composition and abundance of parent and alkylated polycyclic aromatic compounds (PACs) in 11 radiometrically-dated lake sediment cores collected near in-situ operations at Cold Lake Alberta to assess potential petroleum contamination sources to surrounding lakes over the past century. Like open-pit mining areas, alkylated PACs in Cold Lake sediments were elevated compared to unsubstituted parent PACs and increased coeval with the onset of bitumen extraction in the area. Diagnostic ratios and pyrogenic indices showed that PAC sources to these lake sediments were dominantly pyrogenic, likely from historic forest fires, however they shifted to more petrogenic sources coeval with expanding oil sands extraction at Cold Lake. PACs in sediment from regional lakes are weakly correlated to their proximity to in-situ oil wells, once corrected for lake area. These results suggest that in-situ operations, via diesel-fueled vehicular emissions and the combustion of natural gas for steam generation, are a source of PACs to nearby lakes, but PACs did not exceed Canadian sediment quality guidelines for the protection of aquatic life.

Canadian Oil Sands Extraction and Upgrading: A Synthesis of the Data on Energy Consumption, CO2 Emissions, and Supply Costs

As Canadian crude bitumen production from oil sands has increased in recent decades, the nation’s oil and gas industry has become a significant contributor to national greenhouse gas emissions. Canada has developed carbon emission reduction targets to meet its Nationally Determined Contributions and Mid-Century Strategy goals. A detailed profile of energy consumption pathways in the oil sands industry is necessary to identify potential areas of improvement and to monitor progress toward meeting emissions reduction targets. Much of the existing literature for oil sands modeling provides input assumptions with different technological boundaries. For a set of oil sands extraction and upgrading technologies, this study first reviews the literature and then quantifies energy input requirements, CO2 emissions, and operating costs for a set of consistent technological boundaries and energy units. Summary results refer to requirements and costs at the production facility, excluding transportation and blending costs. An energy system diagram of oil sands production that matches these boundaries is provided, which can be used by integrated assessment models, oil sands companies, and government ministries to evaluate the present and future energy consumption and emissions pathways of the oil sands industry.

Fuelling toxic relations: Oil sands and settler colonialism in Canada

How does the often‐invisible nature of pollution affect people's physical health and psychosocial relations, and their well‐being near major industrial projects? Based on long‐term ethnographic fieldwork in Northern Alberta, Canada, this article explores this question by focusing on oil sands extraction on Cree, Dené and Métis nations' homelands with its environmental and socio‐cultural consequences. Looking at different forms of dispossessions and Indigenous concepts of relationality and home, the author argues that pollution should be seen as an act of settler violence instead of merely a by‐product of industry.

Differential protein expression during growth on model and commercial mixtures of naphthenic acids in Pseudomonas fluorescens Pf-5.

Naphthenic acids (NAs) are carboxylic acids with the formula (C n H 2n + Z O2) and are among the most toxic, persistent constituents of oil sands process‐affected waters (OSPW), produced during oil sands extraction. Currently, the proteins and mechanisms involved in NA biodegradation are unknown. Using LC‐MS/MS shotgun proteomics, we identified proteins overexpressed during the growth of Pseudomonas fluorescens Pf‐5 on a model NA (4′‐n‐butylphenyl)‐4‐butanoic acid (n‐BPBA) and commercial NA mixture (Acros). By day 11, >95% of n‐BPBA was degraded. With Acros, a 17% reduction in intensity occurred with 10–18 carbon compounds of the Z family −2 to −14 (major NA species in this mixture). A total of 554 proteins (n‐BPBA) and 631 proteins (Acros) were overexpressed during growth on NAs, including several transporters (e.g., ABC transporters), suggesting a cellular protective response from NA toxicity. Several proteins associated with fatty acid, lipid, and amino acid metabolism were also overexpressed, including acyl‐CoA dehydrogenase and acyl‐CoA thioesterase II, which catalyze part of the fatty acid beta‐oxidation pathway. Indeed, multiple enzymes involved in the fatty acid oxidation pathway were upregulated. Given the presumed structural similarity between alkyl‐carboxylic acid side chains and fatty acids, we postulate that P. fluorescens Pf‐5 was using existing fatty acid catabolic pathways (among others) during NA degradation.

Fuel consumption analysis and cap and trade system evaluation for Canadian in situ oil sands extraction

A better understanding of fuel use and greenhouse gas (GHG) emissions resulting from Canadian oil sands (bitumen) extraction can help to meet the global carbon budget and design effective climate policies. To date, no studies have published actual fuel use data, analyzed drivers for the decline of emission intensities (EIs) from in situ oil sands extraction, and evaluated the effectiveness of the cap and trade system in Alberta that aims to control GHG emissions for the world's fourth largest oil production region. This study retrieved operating fuel use data from a public database for 18 in situ oil sands extraction schemes. From 2015 to 2019, the weighted average of fuel use was 0.23 103 m3/m3 undiluted bitumen. The weighted averages of fuel use for the schemes using Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS) were 0.20 103 m3 fuel/m3 of undiluted bitumen and 0.34 103 m3 fuel/m3 of undiluted bitumen, respectively. The average EIs for SAGD ranged from 0.25 metric ton (t) CO2e/m3 to 0.98 t CO2e/m3, and the average EIs for CSS ranged from 0.61 t CO2e/m3 to 1.18 t CO2e/m3. In addition, the study pointed out that production ramping up and maturity of reservoirs contributed to the decline in EIs. The study concluded that the current Alberta cap and trade system is not effective to control GHG emissions from in situ oil sands extraction. Some operations were rewarded for emission credits because of production increases, rather than actual emission reductions. An industry-wide benchmark (cap) should be considered to encourage competition. An absolute emission cap should be imposed to prevent facilities from simply increasing production to drive down EI values.

The Effects of Naphthenic Acids on Tryptophan Metabolism and Peripheral Serotonin Signalling

Introduction: Serotonin produced in the periphery has been shown to affect glucose and lipid homeostasis. The availability of the amino acid tryptophan, the precursor of serotonin, affects serotonin availability. In addition, the metabolism of tryptophan via the kynurenine pathway produces physiologically active metabolites which have been shown to be altered under conditions of increased adiposity and dysglycemia. There is now evidence demonstrating some environmental xenobiotics, known to affect glucose and lipid homeostasis, can also alter serotonin production and key components of the kynurenine pathway. Recent evidence suggests that exposure to compounds present in petroleum and wastewaters from oil and gas extraction sites can impact endocrine signaling and result in aberrant lipid accumulation and altered glycemic control. However, whether any of these changes can be causally ascribed to altered serotonin synthesis/signaling or tryptophan metabolism remains unknown. The goal of this study was to determine the effects of exposure to naphthenic acid (NA), a key toxicant found in wastewater from bitumen (thick crude oil present in oil sands deposits) extraction on the enzymes involved in tryptophan metabolism and serotonin production. Methods: McA-RH7777 rat hepatoma cells, were exposed to a technical NA mixture for 48 hours at concentrations within the reported range of NA found in wastewaters from oil extraction. We assessed mRNA expression for key rate-limiting enzymes involved in tryptophan metabolism that lead to either serotonin [Tph1] and/or kynurenine [Ido2 and Tdo2] production, as well as downstream enzymes in the kynurenine pathway [Afmid, Kyat1, Aadat, Kyat3, Kmo, Haao, Acmsd, Qprt]. We also examined the effects of NA on prostaglandin synthesis [Ptgs1, Ptgs2, Ptges] and signalling [Ptger2, Ptger4] as prostaglandins have been shown to be induced by serotonin and are linked to hepatic fat accumulation. Results: NA treatment significantly increased Tph1 and Ido2 expression; this occurred in association with a significant increase in the expression of the inducible prostaglandin synthase Ptgs2 (COX-2), prostaglandin E synthase Ptges, and prostaglandin receptors Ptger2 and Ptger4. Acmsd was the only downstream enzyme in the kynurenine pathway that was significantly altered by NA treatment. Conclusion: These results provide proof-of-concept that compounds associated with oil sands extraction have the potential to perturb key components of serotonin synthesis (Tph1) and tryptophan metabolism (Ido2, Acmsd). Furthermore, we found that the increase in Tph1 expression paralleled expression of Ptgs2. As increased prostaglandin production has been reported in association with nonalcoholic steatohepatitis, these data provide a potential mechanism by which exposure to NA and other petroleum-based compounds may increase the risk of metabolic disease.

Growing (with) Muskeg: Oil Sands Reclamation and Healing in Northern Alberta

Scientists working for oil companies in the Athabasca region are developing methods by which to reclaim muskeg (boreal peatlands) on land disturbed by oil sands extraction. The Alberta government requires companies to reclaim disturbed land by achieving equivalent capability of the landscape to support an end land use. Indigenous community members instead define reclamation as establishing not only quantifiable ecological functions, but also relationships to their traditional territories. Tensions emerge as Indigenous concerns are often subsumed within bureaucratic discourses that favour scientific classification and quantification of land uses in reclaimed areas. Divergent responses to muskeg in reclamation activities are informed in part by these competing emphases on quantifiable landscapes as opposed to those that are relational and growing. This article traces this multiplicity through the examination of government and scientific literature and ethnographic fieldwork with Indigenous communities in northern Alberta. Muskeg is used as an analytical tool to explore competing conceptions of land reclamation. Mistranslation of polysemantic terms like muskeg occur on an ontological level, and settler colonial relations and power imbalances between competing languages and knowledge systems proliferate in reclamation activities.

Primary submicron particles from early stage asphaltene precipitation revealed in situ by total internal reflection fluorescence microscopy in a model oil system

Paraffinic froth treatment (PFT) is an essential step in oilsands extraction. The ability to quantitatively understand and control asphaltene precipitation induced by solvent dilution is key to technology innovation in PFT process. In this work, we investigate the early stage of asphaltene precipitation in a model oil system in response to diffusive solvent addition in quasi-2D confinement. Using total internal reflection fluorescence microscope, we provide direct visualization of the size distribution and structural characteristics of asphaltene precipitates with a spatial resolution of ~200 nm and temporal resolution of 250 ms. Our results show the correlation between the size and number of the asphaltene particles and the concentration of the paraffinic solvent in the diluent. Notably the aggregates were found to consist of primary submicron particles with a similar size from 200 nm to 400 nm in radius. These particles may be the primary elementary units that aggregate and form bigger particles via aggregation. The growth time of asphaltene particles decreases with increase n-pentane concentration in the observation area. The findings from this work provide new insight into the effects of solvent mixing on the size distribution and morphological characteristics of asphaltene precipitates that are important for association with water and solids and separation properties.

Erosion-corrosion behaviour of steels used in slurry pipelines

The regular replacement and maintenance of steel pipes used to transport the slurry processed in oil sands mining and extraction represent a major expense for oil sands operations. Erosion-corrosion tests reveal that the performance of the steels is strongly influenced by the slurry velocity, which affects the severity of the erosion-corrosion synergy. In this study, the erosion-corrosion behavior of API 5L X65, X70, and X80 steels was assessed at two different slurry velocities (3.5 and 5 m/s) and two different aeration levels or dissolved oxygen (DO) levels (0.6 and 3.8 ppm). Results of the tests were compared to those of an ASTM A1053 Gr.50 dual-phase (DP) stainless steel and AR400 hard plate. The tests were performed at 60 °C in sand-containing slurry (20% vol. silica) with 500 ppm chloride, which replicated common field conditions. Characterization of the steels was carried out with optical and scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray diffraction technique, micro-mechanical probe, and electrochemical testing. The results showed that at the DO level of 3.8 ppm, the DP stainless steel featured the highest erosion-corrosion resistance at the slurry velocity of 3.5 m/s, while its performance was inferior to that of the carbon steels as the slurry velocity was increased to 5.5 m/s. At the lower DO level, the DP stainless steel erosion resistance was relatively similar to the carbon steels but deteriorated as slurry velocity was increased. Possible mechanisms responsible for the observed variations in the erosion-corrosion resistance under the testing conditions are analyzed and discussed.

Discovering Energy Consumption Patterns with Unsupervised Machine Learning for Canadian In Situ Oil Sands Operations

Canada’s in situ oil sands can help meet the global oil demand. Because of the energy-intensive extraction processes, in situ oil sands operations also play a critical role in meeting the global carbon budget. The steam oil ratio (SOR) is an indicator used to measure energy efficiency and assess greenhouse gas (GHG) emissions in the in situ oil sands industry. A low SOR indicates an extraction process that is more energy efficient and less carbon intensive. In this study, we applied machine learning methods for data-driven discovery to a public database, Petrinex, containing operating data from 2015 to 2019 extracted from over 35 million records for 20 in situ oil sands extraction operations. Two unsupervised machine learning methods, including clustering and association rules, showed that the cyclic steam stimulation (CSS) recovery method was less efficient than the steam-assisted gravity drainage (SAGD) recovery method. Chi-square tests showed a statistically significant association between the CSS recovery method and high SOR (p < 0.005). Two association rules suggested that the occurrence of non-condensable gas (NCG) co-injection produced a low SOR. Chi-square tests on the two rules identified a statistically significant relationship between gas co-injection and low SOR (p < 0.005). Association rules also indicated that there was no association between the production regions and SORs. For future in situ oil sands development, decision-makers should consider SAGD as the preferred method because it is less carbon intensive. Existing in situ oil sands projects and future development should explore the possibility of NCG co-injection with steam to reduce steam consumption and consequently reduce GHG emissions from the extraction processes.

Development of a framework for the assessment of the market penetration of novel in situ bitumen extraction technologies

Greenhouse gas (GHG) mitigation opportunities from emerging in situ mining technologies in oil sands production can play a role in reducing global warming. There is limited research on quantitative assessments of the penetration of emerging oil sands technology in the energy sector. This study addresses this gap by developing a novel framework (MAPL-OET) to assess the market penetration of emerging oil sands extraction technologies. The framework is robust and data-intensive as it combines diffusion models, econometrics models, cost models, and energy-economy equilibrium models. The combined model evaluates the adoption of new energy technologies resulting from carbon price measures and other economic factors, as well as the GHG mitigation potential in the oil sands sector. The accumulated GHG mitigation potential from high carbon and BAU scenarios (i.e., a carbon price of $30/tonne of CO2 in 2030, increasing at a rate of 4%/yr to reach about $105/tonne of CO2) was estimated to be 192.8 Mt of CO2 eq between 2018 and 2050. New extraction technologies also improve average energy intensities by 1.3% annually in the high carbon price scenarios. The developed new framework can help public and private organizations to achieve energy or environmental targets.

Microbubble-Enhanced Recovery of Residual Bitumen from the Tailings of Oil Sands Extraction in a Laboratory-Scale Pipeline

The recovery of valuables from industrial wastewater prior to release to the environment is indispensable to comply with ever pressing economic and environmental imperatives. In this work, microbub...

A protocol for monitoring plant responses to changing nitrogen deposition regimes in Alberta bogs

Bogs are nutrient poor, acidic ecosystems that receive their water and nutrients entirely from precipitation (= ombrogenous) and as a result are sensitive to nutrient loading from atmospheric sources. Bogs occur frequently on the northern Alberta landscape, estimated to cover 6% of the Athabasca Oil Sands Area. As a result of oil sand extraction and processing, emissions of nitrogen (N) and sulfur (S) to the atmosphere have led to increasing N and S deposition that have the potential to alter the structure and function of these traditionally nutrient-poor ecosystems. At present, no detailed protocol is available for monitoring potential change of these sensitive ecosystems. We propose a user-friendly protocol that will monitor potential plant and lichen responses to future environmental inputs of nutrients and provide a structured means for collecting annual data. The protocol centers on measurement of five key plant/lichen attributes, including changes in (1) plant abundances, (2) dominant shrub annual growth and primary production, (3) lichen health estimated through chlorophyll/phaeophytin concentrations, (4) Sphagnum annual growth and production, and (5) annual growth of the dominant tree species (Picea mariana). We placed five permanent plots in each of six bogs located at different distances from the center of oil sand extraction and sampled these for 2 years (2018 and 2019). We compared line intercept with point intercept plant assessments using NMDS ordination, concluding that both methods provide comparable data. These data indicated that each of our six bog sites differ in key species abundances. Structural differences were apparent for the six sites between years. These differences were mostly driven by changes in Vaccinium oxycoccos, not the dominant shrubs. We developed allometric growth equations for the dominant two shrubs (Rhododendron groenlandicum and Chamaedaphne calyculata). Equations developed for each of the six sites produced growth values that were not different from one another nor from one developed using data from all sites. Annual growth of R. groenlandicum differed between sites, but not years, whereas growth of C. calyculata differed between the 2 years with more growth in 2018 compared with 2019. In comparison, Sphagnum plant density and stem bulk density both had strong site differences, with stem mass density higher in 2019. When combined, annual production of S. fuscum was greater in 2019 at three sites and not different at three of the sites. Chlorophyll and phaeophytin concentrations from the epiphytic lichen Evernia mesomorpha also differed between sites and years. This protocol for field assessments of five key plant/lichen response variables indicated that both site and year are factors that must be accounted for in future assessments. A portion of the site variation was related to patterns of N and S deposition.

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands III. Next generation of water‐based oil sands extraction

AbstractCurrent water‐based oil sands extraction operations are unsustainable, due to their consumption of large quantities of water and energy, generation of large volumes of fluid fine tailings, and rapid expansion of tailing ponds. From a brief analysis of the historical evolution of water‐based oil sands extraction, it has been identified that the use of conventional dispersed air flotation to recover liberated bitumen from oil sand slurries is mainly responsible for the high consumption of water required and the fluid fine tailings generated. Based on mineral flotation principles, a new concept is proposed, whereby water‐based oil sands extraction is simplified as a process of transferring hydrophobic bitumen from hydrophilic surfaces (sands) to hydrophobic surfaces (bitumen carriers). Compared to existing bitumen extraction technologies, bitumen liberation from sands is accelerated by attrition/scrubbing, and the liberated bitumen is recovered from the oil sand slurry by hydrophobic coagulation and heavy media separation. This concept is verified from preliminary laboratory tests for processing (above) average grade oil sands. The water required is significantly reduced from 100 to 150 wt% of the ores processed (as seen in current commercial operations) to 30‐40 wt% of the ores. Virtually no fluid fine tailings are generated, with the potential of eliminating tailing ponds. The tailings produced after bitumen extraction are paste‐like, containing >60 wt% solids, which can be directly disposed of in the mining pit, with little or no further treatment. Future research is needed to justify and refine the concept in large‐scale tests and engineer it into commercial operations.

Study on Synthesized Thermoresponsive Block Copolymer for Water-Based Oil Sands Extraction

Thermoresponsive nonionic block copolymers, methoxy poly(ethylene glycol)-b-poly(N-isopropylacrylamide) (MPEG-b-PNIPAM), were investigated as chemical aids for the water-based oil sands extraction ...

Controlling the Interaction Forces between an Air Bubble and Oil with Divalent Cations and Sodium Citrate

Manipulating the interaction forces between an air bubble and oil is of great importance in many industrial processes, such as oil sands extraction. Recently, sodium citrate has been applied in the...

Comprehensive study on cleaner production of heavy oil from Athabasca oil sands using chemical additives in biodiesel-assisted ambient-aqueous bitumen extraction process

The massive unconventional petroleum resources of Athabasca oil sands in Alberta, Canada are currently being excavated and processed using the hot water bitumen extraction (HWBE) process and steam-assisted gravity drainage (SAGD) technology. A major challenge associated with HWBE process is high energy intensity for maintaining an operation temperature of 40–55 °C. Solvent-assisted ambient aqueous bitumen extraction processes, in which a portion of solvent is added for oil sands pretreatment prior to extraction process, have been reported to be capable of reducing the energy intensity via ambient temperature oil sands extraction operations. However, there is still a gap between the current solvent-assisted process and industrial expectations. This study focuses on optimization of biodiesel-assisted ambient aqueous bitumen extraction, an example of the solvent-assisted process, by incorporating methyl isobutyl carbinol (MIBC) and ethylene oxide-propylene oxide (EO-PO) copolymer in oil sands pretreatment. The idea is to take advantage of such chemicals and demulsifiers used downstream of heavy oil (known as bitumen) extraction process by their addition upfront as in the case of biodiesel-assisted hybrid extraction process. With the incorporation of these chemicals and demulsifiers in the improved biodiesel-assisted process, both bitumen liberation and bitumen flotation efficiency were improved significantly with the addition of biodiesel/MIBC mixture at 10 wt% of bitumen. The results from bench-scale experiments revealed a higher bitumen recovery and a cleaner bitumen froth by the improved biodiesel-assisted process at ambient temperature as compared with the traditional biodiesel-assisted process, as well as current industrial HWBE process, featuring a cleaner production of heavy oil from Athabasca oil sands and other heavy oil resources.

Greenhouse gas emission abatement potential and associated costs of integrating renewable and low carbon energy technologies into the Canadian oil sands

The purpose of this research is to evaluate the greenhouse gas reduction potential and associated costs of integrating renewable energy technologies into Canada’s oil sands . There is very limited analysis in the literature focused on the integration of renewable technology options in oil sands processes. This research addresses the gap by developing a novel framework that applies market penetration and bottom-up energy modeling techniques. A total of 27 long-term scenarios across oil sands extraction, upgrading, and electricity generation were investigated. The results show that up to 84 million tonnes of greenhouse gas emissions abatement (2.3% of oil sands GHG emissions) at a marginal greenhouse gas abatement cost of $1.3/tCO2e is available under a $30/tonne carbon incentive. Scenarios with no carbon incentive resulted in 69 million tonnes less greenhouse gas emissions abatement and a marginal greenhouse gas abatement cost increase of $36/tCO2e. Nuclear-based scenarios mitigated the largest amount of greenhouse gases and had the lowest marginal abatement costs. Geothermal energy, bioenergy, and hydropower were cost effective in certain scenarios but had limited greenhouse gas emission reduction potential. Wind and solar technologies failed to displace existing processes in the scenarios considered. The results from this study may be of value to government policy makers and industry representatives aiming to reduce greenhouse gases.

Mid-Infrared Reflectance Spectroscopy of Oil Sands Minerals Based on Tunable Quantum Cascade Lasers.

Minerals play an important role in the oil sands extraction efficiency. It is thus important to assess the major mineral abundance in oil sands ores. This paper presents the application of tunable quantum cascade lasers for mid-infrared reflectance spectroscopy on oil sands minerals. The investigations and results show a new tool to determine oil sands mineral type and to determine potentially quartz and clay contents.

Identification “by eye”: integrative character assessment informs regional field identification of greater fritillary butterflies (Nymphalidae: Speyeria)

The pronounced morphological variability exhibited by Speyeria butterflies can hinder the identification of these taxa, and thus presents a challenge to their management and conservation. While several studies have documented declines in American populations of Speyeria due to habitat change, the response of Canadian populations of Speyeria to widespread anthropogenic pressures remains poorly understood due to their difficult identification. Here, we assessed the utility of morphological characters recommended in regional field guides for the identification of Speyeria butterflies in Canada, focusing on three morphologically variable subspecies that inhabit boreal forests subject to widespread oil sands extraction: S. aphrodite manitoba, S. atlantis hollandi, and S. hesperis beani. We scored 159 specimens for 11 morphological characters, and complimented this data by sequencing the barcode region of the COI gene for 15 of these specimens. Our results indicate a high level of intraspecific variability in several characters, and the COI gene revealed that initial morphological identifications were incorrect. A further assessment of character reliability identified sets of morphological characters that, in combination with specimen sex and species natural history, improved subspecies identification. Notably, we found that a relatively novel field marker—in vivo eye color—consistently distinguished S. aphrodite manitoba from S. hesperis beani and S. atlantis hollandi. Our results emphasize the importance of using an integrative approach for the accurate identification of morphologically variable species, particularly in situations where molecular methods are not readily available, such as citizen science programs.