Oil Sands Research Articles

Treatment of oil sands process-affected water using a semi pilot-scale coalescing filter: Effect of fundamental conditions and water characteristics on filtration performance

The reuse of oil sands process-affected water (OSPW) generated during oil extraction is becoming essential due to oil extraction efficiency and stringent environmental regulations. This study investigates the efficacy of a coalescing filter (CF) in removing oil components from OSPW by exploiting coalescence, which involves merging small oil droplets into larger ones using fibers. Real-time, precise oil measurement systems were employed to evaluate the oil removal efficiency of the CF across synthetic OSPW samples with varying properties. Fundamental conditions and water quality components were systematically adjusted to elucidate the influencing factors on oil removal by the CF. Results showed that despite the diesel having significantly lower viscosity than the oil contents in OSPW, CF achieved a removal efficiency of over 60% within the first 10 min of operation time, regardless of oil concentration. Total suspended solids/turbidity exhibited a decreasing trend as it passed through the filter, indicating fouling occurring within the filter. On the other hands, its increase improved CF performance by 6% compared to baseline conditions, while an increase of alkalinity decreased performance by 10%. When each water quality component exists independently, they do not significantly impact the oil removal efficiency. However, when present together, there is a more decrease in removal efficiency due to the reduced interaction between oil and filter. CF was resistant to changes in water quality. Rather, changes in fundamental factors are more sensitive to CF performance. Filter characteristics and mechanisms make residence time the primary factor affecting oil removal by the CF, with variations exceeding 30% depending on conditions. Therefore, optimizing filter number and flow rate is essential to maximize the filtration performance.

Assessing the Interpretability–Performance Trade-Off of Artificial Neural Networks Using Sentinel Fish Health Data

A number of sentinel species are regularly sampled from the environment near the Oil Sands Region (OSR) in Alberta, Canada. In particular, trout-perch are sampled as a proxy for the health of the aquatic ecosystem. As the development of the OSR began before the environmental monitoring program was in place, there is currently no established measure for the baseline health of the local ecosystem. A common solution is to calculate normal ranges for fish endpoints. Observations found to be outside the normal range are then flagged, alerting researchers to the potential presence of stressors in the local environment. The quality of the normal ranges is dependent on the accuracy of the estimates used to calculate them. This paper explores the use of neural networks and regularized regression for improving the prediction accuracy of fish endpoints. We also consider the trade-off between the prediction accuracy and interpretability of each model. We find that neural networks can provide increased prediction accuracy, but this improvement in accuracy may not be worth the loss in interpretability in some ecological studies. The elastic net offers both good prediction accuracy and interpretability, making it a safe choice for many ecological applications. A hybridized method combining both the neural network and elastic net offers high prediction accuracy as well as some interpretability, and therefore it is the recommended method for this application.

Utilization of Bituminous Sand in the Production of Eco-friendly Sandcrete for Sustainable Construction

Sandcrete is a construction material composed of cement, fine aggregate, and water. The constituent materials are in great demand due to their use in various buildings. The increasing demand in turn has led to astronomical increases in the cost of procuring these materials thereby making it very difficult to meet the shelter provision requirement of the teeming population of a country such as Nigeria. There have been various attempts to address this issue by substituting different materials for river sand in the production of sandcrete, either entirely or in part, one such material which is used in this research is bituminous sand. Bituminous sands are composed of sands, heavy oil and clay that are rich in mineral and water. Ordinary Portland cement was mixed with both river sand (as control) and bituminous sand in 0, 10, 20, 30, 40 and 100% replacement levels. Seventy-two sandcrete cubes were cast in all for this study and tested for compressive strength. From the investigation, the samples compressive strengths increased with increase in curing age and decreased with increase in percentage replacement though at a different rate with the sample containing 0% bituminous sand and 100% river sand denoted SC0,100 gaining the highest strength of 8.59N/mm2 at the 28th day of curing. The SC10,90, SC20,80, SC30,70 and SC40,60 attained 98.5%, 50%, 42.3% and 3.5% more strength compared to the design strength at 28th day of curing, respectively. While the SC100,0 attained 43.5% lower strength compared to the design strength at 28th day of curing. This research has revealed the possibility of using bituminous sand for developing eco-friendly sandcrete for construction purposes for up to 0-40% river sand replacement with bituminous sand.

Technology Focus: Cementing and Zonal Isolation (May 2024)

This past year’s Cementing and Zonal Isolation papers indicated that our industry continues to maintain high levels of innovation and optimization. We saw a healthy mix of both academic and field-specific content. The evident collaboration between operators and service providers continues to propel technical developments at rates otherwise not possible. Geopolymer cementing-systems-development took center stage again, with 11% of the published papers covering this topic, with the ultimate goal of reducing the CO2 footprint of wellbore-sealing materials. Last year’s column described the geopolymer-systems-development timeline and how we had yet to have any case studies published. This year, I invite you to read a paper highlighting the first published field implementation of geopolymer in primary casing cementing, paper OTC 32218. This paper describes techniques that ensure that geopolymer systems are suitable for the downhole application, compatible with existing pumping equipment, and scalable to current operations. Several other papers published this past year describe these specific geopolymer topics in detail. Academic paper SPE 213763 describes the development, testing, and results of a novel resin-cement blend. This innovation stands out because, among other reasons, it presents improved bonding of cement to the casing, which enhances wellbore integrity over the well life cycle. Such materials can provide long-term isolation, especially in environments where conventional cement does not always endure mechanical stresses, vibrations, or shocks. Paper SPE 214768 is a robust case study on the implementation of foamed cements in shallow thermal well applications to mitigate gas migration. This paper showcases best practices for generating solutions to challenging downhole conditions from well design, drilling, and cementing perspectives. While the discussed geology and steam-assisted gravity drainage processes are largely unique to Canadian oil sands operations, I recommend this as an informative read for any operator or service provider facing similar downhole challenges. I hope you gain valuable insight from these selections and am looking forward to what the next year of publications brings to the cementing and zonal isolation space. Some excellent case studies and technological developments are also listed as additional reading. Recommended additional reading at OnePetro: www.onepetro.org. SPE 217797 Cementing: The Good, the Bad, and the Isolated—Techniques To Measure Cement Quality and Its Impact on Well Performance by Kyle Haustveit, Devon Energy, et al. SPE 216911Well Life Extension Through CasingCorrosion Control by A. Yugay, ADNOC, et al. SPE 214538 Using Ultrasonic Flexural Measurements To Validate Casing Standoff Simulations: A Kuwait Case Study by Ahmed Nour, Kuwait Oil Company, et al. SPE 213099 Biomineralization: Surface Injection Eliminates Bradenhead Pressure by Dwight Randy Hiebert, BioSqueeze, et al.

A Grand Challenge: Net-Zero Operations—Changing the Definition of “Business as Usual”

_ This is the second of a series of six articles on SPE’s Grand Challenges in Energy, formulated as the output of a 2023 workshop held by the SPE Research and Development Technical Section in Austin, Texas. Described in a JPT article last year, each of the challenges will be discussed separately in this series: geothermal energy; improving recovery from tight/shale resources; net-zero operations; carbon capture, storage, and utilization; digital transformation; and education and advocacy. The first article, “An SPE Grand Challenge Update on Geothermal Energy,” was published in April 2024. _ At COP28, more than 50 oil and gas companies, many of them national companies, took a historic step toward decarbonization by launching the Oil & Gas Decarbonization Charter. The charter represents significant short- and long-term ambitions to reduce emissions, including net-zero operations by 2050 at the latest. This article explores the importance of this effort, the opportunities available to the industry to reduce its Scope 1 and 2 emissions, and the key technologies needed to achieve the net-zero goal. The Size of the Prize According to the latest data from the International Energy Agency (IEA), the production, transport, and processing of oil and gas resulted in 5.1 GtCO2e in 2022. These emissions stem from the production and delivery of oil and gas and the combustion of fossil fuel necessary for operations on-site (Scope 1), and the import of electricity from external sources consumed in oil and gas facilities (Scope 2). These Scope 1 and 2 emissions represent just under 15% of global energy-related greenhouse gas (GHG) emissions. This is a sizable contribution, nearly equivalent to all energy-related GHG emissions from road transport, highlighting the relative scale of the opportunities associated with implementing operational changes in the industry. The faster and deeper these emissions reductions are, the more significant the impact will be. Sources of Emissions To understand the various paths to net zero an oil and gas company can follow, it is critical to map the sector’s sources of emissions throughout the value chain. It is generally recognized that around 60% of an integrated company’s emissions emanate from upstream operations, predominantly from onshore assets. Refining and distribution are the second main contributors, but of a smaller order of magnitude, notably because of significant efforts already made by companies to reduce emissions from their refining assets and levers of decarbonization potentially easier to implement. However, emissions volumes and intensities differ significantly across regions, countries, and asset types. An asset operating in the Canadian oil sands region will have a very different emissions profile compared to an offshore platform in Western African countries. These differing profiles also call for tailored emission-reduction approaches. This means decarbonization studies must be carried out at the asset level, allowing operators to identify the most cost-effective means of tackling emissions reduction.

Multi-stage development process and model of steam chamber for SAGD production in a heavy oil reservoir with an interlayer.

Steam-assisted gravity drainage (SAGD) is an efficient thermal recovery technique for oil sands and extra heavy oil exploitation. The development of steam chamber goes through multi-stage physical processes for SAGD production in a heavy oil reservoir with an interlayer. In this study, considering the situation that an interlayer is located directly above a pair of horizontal wells, we analyzed the whole process of steam chamber development. We divided the whole process into stages I-V, which are the first rising stage, the first lateral expansion stage, the second rising stage, the second lateral expansion stage and the confinement stage, respectively. Particularly, we further divided stage II into 2 periods and stage IV into 3 periods. These stages and periods can help us understand the development process of steam chamber dominated by an interlayer more profoundly. Based on the divided stages and periods, we established different models of SAGD production by assuming different geometric shapes of steam chamber in different stages and periods. Oval shape was assumed in stages I and III, and inverse triangle shape was hypothesized in stages II, IV and V. The formulas of the front distance of steam chamber and the oil production rate of SAGD were deduced from the established models for different development stages. At the end, we performed two example applications to SAGD production in heavy oil reservoirs with an interlayer. The real oil production rates were matched very well with the theoretical oil production rates calculated by the deduced formulas, which implies the multi-stage development model of steam chamber is of reliability and utility.

Stochastic Inversion in Determining the Distribution of Petroleum Carrying Sandstones in the "JS" Field of the South Sumatra Basin

The "JS" field is a field located in the South Sumatra Basin, where the field has good prospects for the distribution of petroleum-bearing sandstone. The target of this research is the Air Benakat formation. This research uses the stochastic seismic inversion method to determine the probability of finding petroleum in sandstone. Stochastic seismic inversion has the advantage that it can overcome thin layers and can reduce existing data misalignments. So stochastic inversion can overcome the shortcomings of other seismic inversions, especially model-based seismic inversion which is the initial model for stochastic seismic inversion. Stochastic seismic inversion produces several realizations by showing uncertainty so as to get results that are close to the actual situation. Probability map of oil-bearing sandstones located in the north and east of the study area. with the slice results obtained for the acoustic impedance range of 8517-9051(m/s)*(g/cc) and oil sand probability with a value range of 0.61-0.78%.

Coupling Mechanism of Multiple-Thermal-Fluid Multi-Cycle Stimulation in Ultra-Heavy-Oil Reservoirs

Multiple-thermal-fluid (MTF) stimulation technology has been successfully applied in heavy-oil reservoir development, resulting in the significant enhancement of oil production. However, the underlying mechanism of multi-component coupling remains unclear. This paper constructs a coupling model for MTF stimulation, investigates the coupling mechanism of different media in various zones during multiple-cycle stimulation operations, and compares the implementation effect with field results. The findings reveal that (1) based on media distribution, the area from near-wellbore to far well locations can be divided into four zones: high-temperature oil-viscosity-reduction zones, compound action zones, energy-replenishment zones, and unaffected zones. (2) In the high-temperature oil-viscosity-reduction zone, the latent heat of vaporization is released by steam, and ultra-heavy oil absorbs heat and reduces its viscosity, which plays a dominant role in the production of MTF. In the compound action zone, hot water, CO2, and N2 exhibit a synergistic effect which enhances overall performance. In the energy-replenishment zone, a small amount of N2 provides pressure maintenance and an additional energy supply. (3) As more cycles of stimulation are conducted, the compound action zone expands, while the energy-replenishment zone contracts. Simultaneously, there is a decrease in contribution rate from the high-temperature viscosity-reduction zone to oil production but an increase from both the compound action zone and energy-replenishment zone up to 30%. Based on the dynamic law of representative wells, this paper proposes a multi-media zonal coupling mechanism, providing a reference for subsequent research on MTF stimulation mechanisms and the adjustment of production measures.

Low adsorption affinity of athabasca oil sands naphthenic acid fraction compounds to a peat-mineral mixture

Much of the toxicity in oil sands process-affected water in Athabasca oil sands tailings has been attributed to naphthenic acids (NAs) and associated naphthenic acid fraction compounds (NAFCs). Previous work has characterized the environmental behaviour and fate of these compounds, particularly in the context of constructed treatment wetlands. There is evidence that wetlands can attenuate NAFCs in natural and engineered contexts, but relative contributions of chemical, biotic, and physical adsorption with sequestration require deconvolution. In this work, the objective was to evaluate the extent to which prospective wetland substrate material may adsorb NAFCs using a peat-mineral mix (PMM) sourced from the Athabasca Oil Sands Region (AOSR). The PMM and NAFCs were first mixed and then equilibrated across a range of NAFC concentrations (5–500 mg/L) with moderate ionic strength and hardness (∼200 ppm combined Ca2+ and Mg2+) that approximate wetland water chemistry. Under these experimental conditions, low sorption of NAFCs to PMM was observed, where sorbed concentrations of NAFCs were approximately zero mg/kg at equilibrium. When NAFCs and PMM were mixed and equilibrated together at environmentally relevant concentrations, formula diversity increased more than could be explained by combining constituent spectra. The TOC present in this PMM was largely cellulose-derived, with low levels of thermally recalcitrant carbon (e.g., lignin, black carbon). The apparent enhancement of the concentration and diversity of components in PMM/NAFCs mixtures are likely related to aqueous solubility of some PMM-derived organic materials, as post-hoc combination of dissolved components from PMM and NAFCs cannot replicate enhanced complexity observed when the two components are agitated and equilibrated together.

Comprehensive characterization of organics in oil sands process water in constructed mesocosms utilizing multiple analytical methods

This study aims to provide a thorough characterization of dissolved organics in oil sands process water (OSPW) in field-based aquatic mesocosms at both molecular and bulk measurement levels using multiple analytical methods. In a 3-year outdoor mesocosm experiment, the analysis of naphthenic acid (NA) species was conducted using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOFMS). The results revealed the removal of both total NAs (38% and 35%) and classical NAs (O2–NAs, 58% and 49%) in undiluted and half-diluted OSPW, respectively. The increased ratios of oxidized NAs (O3–O6 NAs) to classical NAs suggested a transformation trend. The results also indicated that O2–NAs with higher carbon number and lower double bond equivalent (DBE) were more easily degraded in the mesocosm systems. Biomimetic extraction using solid-phase microextraction (BE-SPME) measurement displayed 26% (undiluted OSPW) and 30% (half-diluted OSPW) decrease in total bioavailable organics over 3 years. Naphthenic acids fraction compounds (NAFCs) obtained by liquid-liquid extraction (LLE) were also determined using Fourier transform infrared spectroscopy (FTIR). Reduction in acute toxicity for undiluted (43%) and half-diluted (26%) OSPW was observed over 3 years, which are well correlated with the decreases of NAs and BE-SPME concentrations. Moreover, BE-SPME values were found to be linearly correlated with total NAs concentrations (r = 0.96) and NAFCs (r = 0.96). Additionally, the linear relationships of individual O2–O6 NA species and BE-SPME concentrations unveiled the changes in the relative abundances of O2–O6 NA species in total bioavailable organics over time in the mesocosms. The present study has provided comprehensive insights by integrating various analytical methods, contributing valuable information for assessing the effectiveness of aquatic mesocosm systems in studying the temporal changes of organics in OSPW.

Research on the Influence of Sand-Mud Interlayer Properties on the Expansion of SAGD Steam Chamber

Summary Thermal recovery techniques serve as the primary approach for developing heavy oil due to its high viscosity and poor flowability. In this study, we established a high-temperature and high-pressure 3D physical experimental and numerical model based on the unique reservoir characteristics of the sand-mud interlayer in the Long Lake oil sands of Canada, using similarity criteria. Physical and numerical experiments employing steam-assisted gravity drainage (SAGD) were conducted to investigate the impact of sand-mud interlayer properties on the expansion limit of steam chambers during SAGD development. The results indicate that the expansion mode and limit of the steam chamber play a decisive role in heavy oil mobilization. Notably, heat loss during steam chamber expansion and the flow resistance caused by the interlayer are critical factors influencing the SAGD process. The presence of the interlayer extends the mobilization range in the lower portion of the reservoir, but it also limits the upward expansion of the steam chamber, resulting in a reduced mobilization range above the interlayer. Moreover, the steam chamber above the interlayer exhibits a distinct expansion pattern, featuring concave sides and a convex middle, resembling a “positive triangle.” Furthermore, the properties of the sand-mud interlayer and production parameters significantly affect the expansion limit of the steam chamber. Permeability and position exert a substantial impact on recovery, whereas thickness has a minor influence. Specifically, at an injection rate of 20 mL·min–1, steam quality of approximately 0.7, and a production/injection ratio of approximately 1.0, the steam chamber can successfully penetrate interlayers with a thickness of either 3.5 m and a permeability of 100×10−3 μm2 or 4.5 m and a permeability of 200×10−3 μm2.

Microstructural characterization and corrosion behaviour of heat treated standard stainless steels in tar sand

This paper aims to investigate the corrosion behaviour of heat-treated standard duplex stainless steel (UNS S32205) in the recovery of bitumen from Nigerian-rich tar sand, using sodium hydroxide (NaOH) as the process solution. Appropriate material family needs to be identified for the exploitation of tar sand resources to ensure sustainable extraction of bitumen. UNS S32205 offers exceptional mechanical properties and excellent corrosion resistance which makes it a great material choice for demanding applications, including offshore platforms and construction projects. Samples of UNS 32205 were heat-treated and immersed in the digested tar sand, maintaining a process temperature of 90°C. The microstructure of the corrosion coupons was studied using SEM/EDS (Scanning Electron Microscope/Energy Dispersive Spectroscope), and the corrosion rate of the samples was derived using gravimetric technique following ASTM G31 standard. The SEM micrographs indicated varying degrees of pits associated with the passivity of UNS 32205 and an imbalance between its ferrite and austenite phases due to the presence of secondary precipitates formed during heat treatment.The normalized sample, having a corrosion rate of 0.053 mm/year, exhibited the best corrosion resistance, followed by oil quenching (0.054 mm/year), then annealing (0.076 mm/year), and water quenching (0.077 mm/year), where they all showed improved corrosion resistance over the as-received sample having a corrosion rate of 0.078 mm/year.

CPD model prediction of oil sand pyrolysis based on structural parameters from 13C NMR and FTIR measurements

Here, carbon-13 nuclear magnetic resonance spectroscopy (13C NMR) and Fourier transform infrared spectroscopy (FTIR) techniques were used to study the chemical structure characteristics of oil sand and its pyrolysis oil. The FTIR results showed that the values of the CH2/CH3 ratio, A-factor, and DOC1 of the pyrolysis oil decreased during the pyrolysis process, while the C-factor showed a maximum value with increasing pyrolysis temperature. The 13C NMR results showed that methylides and methylides were mainly contributed to oil production. The aliphatic chain in the pyrolysis oil has little alterations during pyrolysis, while the extent of aromatic ring substitution increases from 0.46 to 0.58. Furthermore, a correlation was obtained between the chemical structure of oil and the pyrolysis product yields of oil sand. Moreover, using chemical structure parameters investigated with FTIR and 13C NMR and kinetic parameters based on the thermogravimetric data, the chemical percolation devolatilization (CPD) model was applied to simulate the pyrolysis of oil sand. The results showed that the simulated results for tar and light gas were in good agreement with the experimental data, while those for char underpredicted the experimental data. Overall, the CPD model can effectively predict the pyrolysis of oil sand.

Comparative study on the extraction strength of solvents on tar sand from Okitipupa, Ondo State

Tar sand, an aggregate of sand, clay, water and bitumen was sampled from Okitipupa area of Ondo State, Nigeria, extracted and optimized using n-hexane and toluene in a soxhlet extractor todetermine solvent effectiveness in extracting the bitumen content and their environmental effect. The experiment was carried out by heating the solvent at and above their boiling temperatures solely to get an optimum yield at a temperature and time of extraction of oil from the tar sand. The analysis gave an optimal yield of 9.07 % at 75oC in 4 h when n-hexane was used and an optimal yield of 21.27 % at 120oC in 4 h when toluene was used. A drastic change in colour was also notice in the sand residue to almost sandy soil nature when toluene was used as solvent compare to when n-hexane was used which shows a slight change from its blackish nature. The change in colour of the black tar sand is an indication of high extraction efficiency. Hence, owing to high demand for conventional oil supply in the country and the urgent need for an alternative source of oil, the bitumen extract can serve as an alternative source of unconventionaloil supply in Nigeria and feedstock in refineries.

Canadian productivity growth: Stuck in the oil sands

AbstractWe study the behaviour of Canadian Total Factor Productivity (TFP) growth over the past 60 years. We find that the observed stagnation during the last 20 years is accounted for entirely by the oil sector. Higher oil prices made capital‐intensive sources of oil like the oil sands viable to extract on a commercial scale. However, the greater input required per barrel of oil slowed TFP growth. Comparing Canadian TFP growth with that of the United States and Norway reinforces these results. However, our result should not be interpreted to carry any welfare implications.

An Improved Continuum Approach for Unconsolidated Formations on the Field Scale

Summary With the development of unconventional resources, such as oil sands and methane hydrate reservoirs, the importance of the mechanical performance model for underground unconsolidated rocks has increased significantly. The commonly used numerical approach for unconsolidated rocks is the discrete-element method (DEM). However, the extensive calculations required by the DEM make it inadequate for simulating unconsolidated rock behavior on a field scale. An alternative is the continuum approach, used to simulate the behavior of unconsolidated rocks on the field scale. In previous continuum approaches, unconsolidated rocks have been modeled as a visco-plastic fluid (i.e., Bingham fluid). The continuum approach based on visco-plastic fluid uses pressure (scalar) to describe the stress state of the particles. However, this approach does not account for the difference between the maximum and minimum principal stresses of the in-situ stress field when simulating the mechanical performance of unconsolidated rocks. Here, we developed an improved continuum approach for unconsolidated rocks and used the finite-element method as a numerical approach. Our improved model can consider the difference between the maximum and minimum principal stresses of the in-situ stress field and the pore pressure of the unconsolidated formation. We validated our numerical model with the angle of repose test, a benchmark problem for unconsolidated rocks. The validation results confirm the accuracy of our unconsolidated model. For the coupled model between the unconsolidated model and the flow model, we used an analytical solution to verify its reliability. Unconsolidated rock performances in an unconsolidated reservoir with fluid injection have been investigated based on our coupled model. The simulation results show that injection can activate the movement of unconsolidated rock particles, leading to changes in the distribution of effective stress and permeability. Our model has the potential to address large-scale unconsolidated rock issues and contribute to energy extraction.

Enhancing object detection and classification using deep learning: A novel approach with annotated dataset and YOLO-C3GTR architecture

In the rapidly evolving field of computer vision, the need for advancements in object detection is paramount. For a variety of reasons, including security, maritime surveillance, and environmental monitoring, the identification and categorization of ships in aerial pictures is an essential component. In this study, two distinctive approaches are proposed to improve the accuracy of ship detection and categorization in satellite imagery. In the beginning, the dataset for ship detection that was provided by Airbus was separated into five distinct categories: oil tanker, bulk carrier, container ship, sand carrier, and general ship class. Setting up this division was done with the idea of increasing the precision of the ship classification in the imagery. Moreover, we deployed the YOLO-C3GTR model, which is part of our Object Detection framework and helped us to distinguish ships using the technique of Object Detection. The application of the methodology that we have proposed has the potential to significantly improve the precision of these systems when they are used in real-world scenarios and to make a novel addition to the field of ship identification and classification. We have used multiple algorithms of YOLOv5 tested on this dataset like TPHYOLOv5, YOLOv5x, YOLOv5l and our proposed architecture YOLO-C3GTR and it surpassed all the existing approaches by the mAP of 0.83. Furthermore, we intend to perform additional research in this field while simultaneously working to improve our technique. A comparison was made between the performance of the model and that of other deep learning approaches. The model was evaluated and trained with the categorized dataset.

In-Situ Combustion for Heavy Oil and Oil Sands Recovery: Recent Progress, Field Applications, and Future Perspectives

In-Situ Combustion for Heavy Oil and Oil Sands Recovery: Recent Progress, Field Applications, and Future Perspectives

Ducks: Two Years in the Oil Sands, Kate Beaton (2022)

Ducks: Two Years in the Oil Sands, Kate Beaton (2022)

Molecular insights into oil detachment from hydrophobic quartz surfaces in clay-hosted nanopores during steam–surfactant co-injection

Thermal recovery techniques for producing oil sands have substantial environmental impacts. Surfactants can efficiently improve thermal bitumen recovery and reduce the required amount of steam. Such a technique requires solid knowledge about the interaction mechanism between surfactants, bitumen, water, and rock at the nanoscale level. In particular, oil sands ores have extremely complex mineralogy as they contain many clay minerals (montmorillonite, illite, kaolinite). In this study, molecular dynamics simulation is carried out to elucidate the unclear mechanisms of clay minerals contributing to the bitumen recovery under a steam–anionic surfactant co-injection process. We found that the clay content significantly influenced an oil detachment process from hydrophobic quartz surfaces. Results reveal that the presence of montmorillonite, illite, and the siloxane surface of kaolinite in nanopores can enhance the oil detachment process from the hydrophobic surfaces because surfactant molecules have a stronger tendency to interact with bitumen and quartz. Conversely, the gibbsite surfaces of kaolinite curb the oil detachment process. Through interaction energy analysis, the siloxane surfaces of kaolinite result in the most straightforward oil detachment process. In addition, we found that the clay type presented in nanopores affected the wettability of the quartz surfaces. The quartz surfaces associated with the gibbsite surfaces of kaolinite show the strongest hydrophilicity. By comparing previous experimental findings with the results of molecular dynamics (MD) simulations, we observed consistent wetting characteristics. This alignment serves to validate the reliability of the simulation outcomes. The outcome of this paper makes up for the lack of knowledge of a surfactant-assisted bitumen recovery process and provides insights for further in-situ bitumen production engineering designs.