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Increased global energy consumption has resulted in more waste and greenhouse gas emissions.

Summary The application of horizontal well drilling technology and volume fracturing technique makes the economic development of shale oil reservoirs feasible. The unknown fracture networks lead to severe nonlinearity and high uncertainty during fracture characterization. Moreover, the reservoir parameters usually exhibit a highly non-Gaussianity. Therefore, the key challenges for history matching in fractured shale oil reservoirs are effectively representing the fracture network and coping with the non-Gaussian distribution of reservoir-model parameters. In this work, a new characterization method for complex fracture networks is established, in which the distribution of connected fractures of the reservoir domain is represented by some statistical parameters such as fracture dip angle, fracture azimuth, and fracture half-length and some deterministic parameters such as the coordinates of fracture center points. In the uncertainty quantification and history-matching process, an integrated approach that combines the particle filter and an improved kernel density estimation (KDE) based on its Shannon entropy (SE) for estimating fracture distributions and physical parameters is presented. An adaptive mechanism based on Kullback-Leibler divergence (KLD) is introduced in the proposed history matching workflow, which automatically adjusts the number of particles to reduce the computational burden. Two examples of 3D shale oil production were constructed to validate the efficiency and accuracy of the proposed method. Results showed that the method was capable of capturing the main features of the fracture distributions in the reference cases. The proposed method has the potential to be applied in more complex cases such as multiple wells and multiphase flow.

Prediction and control of the behavior of asphaltenes have always been one of the most challenging topics in the oil and gas industry. To this aim, comprehensive knowledge of the bulk and surface behavior of asphaltenes and the possible interrelationship are required. Many attempts have been done so far to scrutinize the behavior of asphaltenes at the oil/water interface. In this study, the changes in surface behavior of asphaltenes upon aromaticity variation in the bulk are investigated. For this purpose, dynamic light scattering (DLS) experiments are accompanied with dynamic interfacial tension (IFT), and interfacial rheology measurements to analyze the asphaltene aggregation size, mobility and surface activity upon a change in the bulk aromaticity. A wide range of aromatic conditions was used to cover possible changes in asphaltene behavior before and after the onset point. The results revealed that the interfacial activity and the structure of the interfacial film of the asphaltenes are significantly influenced by the bulk properties. Low aromaticity conditions led to an increase in asphaltene surface activity and changed the dilational rheological parameters considerably although the general trend of the asphaltene adsorption remained similar. Moreover, the results demonstrated the importance of the aging time on the measured parameters, particularly for the samples beyond the onset point. Our findings also showed the importance of dynamic interfacial data over static ones. Finally, by applying the concept of diffusion coefficient it was suggested that only a small portion of asphaltenes remain surface-active practically, although their surface activity is directly correlated with the system aromaticity.

Recently, the application of nanoparticles for enhancing oil recovery (EOR) in carbonate reservoirs has received great attention from various researchers across the oil and gas industry. In contras...

A large number of researchers have endeavored to delineate the effects of injecting brine with a low ionic strength in oil reservoirs in the past decade. However, we still cannot conclude the overr...

Effects of pressure on thermo-oxidative decomposition of different sources of n-C7 asphaltenes were investigated at high pressure using a thermogravimetric analyzer under an air atmosphere. The n-C...

Using Quinolin-65 (Q-65) and Violantrone (V-79) as model molecules for polar heavy hydrocarbons and resins, the nanosize effects of NiO nanoparticles on the competitive molecular adsorption on nano...

Polymer-induced drag reduction (DR) in fluids was studied using a rotational rheometer with double-gap concentric cylinder geometry. Although both polymers (polyacrylamide (PAM) and 2-acrylamido-2-methylpropane sulfonic acid (SPAM)) had molecular weights of several MDa, the contrasting polymer charge, nonionic and anionic, led to different polymer overlap concentrations (c*), PAM ≫ SPAM, and fluid rheology, with PAM fluids mostly Newtonian and SPAM fluids non-Newtonian (shear-thinning). Based on these differences, it was important to account for the infinite shear viscosity and normalize the polymer concentration by the intrinsic concentration (cint) so that the DR performance of the two polymer fluids could be accurately compared. Both polymers induced DR, and the maximum DR by SPAM (DR% = 28) was slightly higher than that by PAM (DR% = 22) when Rep ∼ 1700. For PAM, the loss of DR with time diminished at higher polymer concentrations (≥100 ppm, at Rep = 3149) but was found to be sensitive to high Rep, with polymer chain scission the likely cause of the reduced performance. For the semi-dilute SPAM fluids, the shear stability contrasted that of PAM, showing negligible dependence on the polymer concentration and Rep. The apparent rapid loss of DR was predominantly attributed to a time-dependent effect and not polymer degradation. In pipe flow, the maximum DR for SPAM was higher than that measured by rheometry and was attributed to differences in the flow conditions. However, changes in the normalized DR/c with polymer concentration were found to be consistent between the two flow geometries. Furthermore, the high fluid stresses in pipe flow (at high Rep) led to drag reduction losses consistent with PAM, as the time-dependent effect was not seen.

Magnetic nanoparticles have been successfully used to recovery oil from oil spilled on water. Two different methods, floating and vortex, were employed to promote the interaction of four oil samples with different API (e.g., 10, 20, 28 and 45) spilled on seawater and deionized water with three magnetic materials, namely: magnetite nanoparticles (N); magnetic nanocomposites of yeast biomass provided by ethanol industry (Y); and magnetic nanocomposites of cork powder (C). The magnetic nanomaterials exposed to oil on water were taking out by a neodymium magnet, and the oil recoveries were determined by gravimetric analysis before and after lyophilization. The lyophilization was determinant to guarantee the accuracy of the experiments, and without this step, the masses of oil recovered would be overestimated due to the drag of water during the oil and magnetic material removal process. Three main factors, API, contact method and magnetic material, and two interactions (i.e., API × contact method, and contact method × magnetic material) presented a statistically significant effect on oil recovery. It was observed that oil recovery increases as API decreases, and it was possible to establish a model to predict the amount of recovered oil according to this effect. Higher oil recoveries were also obtained by magnetic nanocomposites of yeast biomass (Y), regardless of the contact method and type of water, recoveries of 23% and 100% for 45 and 10 API, respectively, employing around 20 mg of Y on 300 mg of spilled oil. These percentages correspond to 0.29 ± 0.01 kg/kg and 15.98 kg/kg of recovering oil by the magnetic procedure. The increase of mass of magnetic material improved the recovery of oils with higher APIs. The reusability of the spent materials presents potential for its application in oil spill cleaning technologies.

This work is a first attempt to understand the mechanism of metformin thermal decomposition under inert conditions. Thermal gravimetric analysis coupled with mass spectrometry was used to probe the thermal degradation reactions. Density functional theory and second-order perturbation (MP2) theoretical calculations were used to construct a reaction mechanism for metformin decomposition. It was evident that the reactions are initiated via formation of methyl radicals, and ammonia via 1.3-H shift, followed by a series of different secondary reaction pathways. The formation of cyanamide, dimethylamine and HCN were among the main secondary products. The proposed mechanism is important for future treatment of wastewater containing metformin and similar drugs formulations, and their possible conversion to useful commodities.

Oil sands exploitation in Alberta relies on water-intensive processes that result in large amounts of oil sand process-affected water (OSPW). Tailings ponds are used to store OSPW in accordance with government regulations. One of the main challenges of these tailings ponds is the settling of fine particles which, without treatment, would remain suspended for decades. This study introduces a novel application for the oxy-cracking technique to enhance fine particle settling through simultaneous oxidation and cracking reactions: residual bitumen and hydrocarbons are cracked and solubilized in the liquid phase, freeing the fine particles to agglomerate and settle faster. The pathway for this process is determined by the kinetics parameters, and it releases minimal CO2. A full lumped kinetics model study is presented to describe the oxy-cracking reaction. Settling enhancement and dewaterability were studied using the initial settling rate (ISR) and capillary suction time (CST) methods. After oxy-cracking, the ...

Synergistic effects between nickel and cerium in catalytic water gas shift reaction (WGSR) have been widely reported, mostly using cerium as an active support coupled with nickel as a dispersed phase. Although, these metals are extensively used in industry, and their price has continuously raised, catalysts containing highly dispersed nickel and cerium are less investigated. This work tackles catalysts with low percentages (0–3 wt%) of well dispersed nickel and cerium in MFI framework. Catalysts containing only incorporated cerium exhibited no activity, while the single metal Ni-MFI series catalyzed the reaction. The prepared Ni-Ce-MFI series synergistically accelerated WGSR even at temperatures as low as 503 K, and some reach equilibrium conversion below 548 K. The catalytic performance increased by nickel content, and catalysts with similar mass percentage of cerium and nickel outperformed others. Furthermore, their maximum reduction temperatures occurred at ∼60 K lower, confirming their higher performance in WGSR.

Nanoparticles (NPs) have recently gained great attention as effective agents for enhanced oil recovery (EOR) applications, especially at ambient temperatures. Nevertheless, harsh conditions are nee...

Pharmaceutical compounds are emerging contaminants that have been detected in surface water across the world. Because conventional wastewater treatment plants are not designed to treat such pollutants, new technologies are needed to degrade and oxidize such contaminants. The newly developed oxy-cracking process was utilized to treat the antidiabetic drug, metformin. The process, which involved partial oxidation of metformin in alkaline aqueous medium, proved to decompose the drug into small organic molecules, with minimum emission of CO2, therefore, increasing its biodegradability and removal from industrial treatment plants. The reaction gaseous products were probed by online gas chromatography. The liquid phase before and after oxy-cracking was analyzed for total carbon content by TOC and gas chromatography mass spectrometry. The products formed from the nitrogen-rich drug included ammonia, amines, amidines, and urea derivatives. A reaction mechanism for the oxy-cracking process is proposed. Because the hydroxyl radical (˙OH) is believed to play a central role in the oxy-cracking process, the mechanism is initiated by ˙OH attacks on metformin, followed by single decomposition or isomerization steps into stable products. The reactions were investigated using density functional theory calculations and validated using high quality 2nd order Moller–Plesset perturbation theory energy calculations.

Oil spill is a serious environmental concern, and alternatives to remove oils from water involving biosorbents associated to nanoparticles is an emerging subject. Magnetite nanoparticles (MNP) and yeast magnetic bionanocomposite (YB-MNP) composed by yeast biomass from the ethanol industry were produced, characterized, and tested to remove new motor oil (NMO), mixed used motor oil (MUMO) and Petroleum 28 °API (P28API) from water following the ASTM F726–12 method, which was adapted by insertion of a lyophilization step to ensure the accuracy of the gravimetric approach. Temperature, contact time, the type and the amount of the magnetic material were the parameters evaluated employing a fractional factorial design. It was observed the removal of 89.0 ± 2.6% or 3522 ± 118 g/kg (NMO) employing MNP; 69.1 ± 6.2% or 2841 ± 280 g/kg (MUMO) with YB-MNP; and 55.3 ± 8.2% or 2157 ± 281 g/kg (P28API) using MNP. The temperature was the most significant parameter in accordance with the Pareto's graphics (95% confidence) for all oil samples considered in this study as well as the two magnetic materials. Contact time and the interaction between the materials and temperature were also relevant. The D-Optimals designs showed that the NMO and P28API responded in a similar way for all evaluated parameters, while the uptake of MUMO was favored at higher temperatures. These behaviors demonstrate the influence of oil characteristics and the intermolecular forces between the oil molecules on the mechanism dragging process performed by the attraction between magnetite nanoparticles and a 0.7 T magnet. It was clear that this kind of experiment is predominantly a physic phenomenon which cannot be described as adsorption process.

This study focuses on detailed characterizations of asphaltene fractions extracted from the Algerian Hassi-Messaoud oil field. It was found that the extracted asphaltenes are not completely soluble in toluene, instead two fractions of asphaltenes were obtained upon solubilizing the heptane-precipitated neat asphaltenes in toluene. Extensive characterizations of the toluene-soluble and insoluble fractions were carried out using elemental analysis, Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (ssNMR). It was suggested that the high oxygen content and uneven compositional structures are the main contributors to asphaltene instability. The toluene-insoluble fractions were found to have higher polarity and aromaticity as well as more oxygen content than the neat asphaltenes and toluene-soluble fractions.

Efficient removal of heavy metals from water and wastewater is a necessity for human and environmental well-being. Agricultural, domestic, and industrial waste discharges increase with the increase in the global population. Discharges are loaded with toxic metallic substances that inevitably reach water sources. Conventional treatment methods are in many cases inadequate in their removal efficiencies. Alternatively, recently developed advanced treatment approaches, such as nanotechnologies, offer advantages in water treatment. Nanotechnology brought about materials with high specific surface areas and adsorption capacities for the removal of undesirable heavy metals present in water. A detailed review of the use of nanotechnologies and nanomaterials for the removal of heavy metals from aqueous solutions is presented in this study. Limitations, research gaps, and suitability of nanotechnology in water treatment for the removal of heavy metals at a large scale are discussed, and relevant conclusions are accordingly deduced.

Nanoparticle technology is emerging as a new technology with wide applications in health, energy, and the environment. However, this technology is considered a double-edge sword technology as it has several advantages but a number of challenges. Production of cost-effective and environmentally friendly nanoparticles, at commercial scale, is one of the main challenges facing this technology. Our research group at the University of Calgary specifically focuses on innovation of naturally derived nanoparticle-based materials and processes. Discoveries made in our laboratory have a wide range of practical applications, including CO2 capture and conversion, heavy oil upgrading and recovery, oil spill clean-up, water remediation, wastewater treatment, treatment of mature fine tailings, natural gas conditioning, and utilization of waste-heavy hydrocarbons, such as asphaltenes and petroleum coke. The state-of-the art approaches and technologies developed by our group provide substantial benefits to industry and society in terms of process simplification, reduced cost, energy efficiency, and reduction of greenhouse gas emissions. In this chapter, we focus on the synthesis of naturally derived Aegirine nanoparticles with different sizes, shapes, and surface functionalities. We provide details on different aspects of nanoparticle synthesis including several functionalization or grafting methods to customize their use in desired applications. Examples of the applications of customized modified nanoaegirine as adsorbent and catalysts are provided. This chapter provides valuable information on understanding nanoaegirine preparation conditions, structure and surface modifications, and their adsorptive and catalytic behavior toward heavy organic compounds.

This work investigates the thermo-oxidative behaviour of saturates, aromatics, and resins, at different pressures of 0.084, 3.0, and 6.0 MPa. Saturates (S), aromatics (Ar), and resins (R) were characterized by elemental analysis, vapor pressure osmometry, 1H- and 13C-nuclear magnetic resonance, and X-ray photoelectron spectroscopy. The atmospheric evaporation of S, Ar, and R was evaluated by simulated distillation, whereas high-pressure distillation curves were created by calculation using the Clapeyron equation with the Redlich Kwong equation of state. The mass change and rate of mass change profiles were assessed in a high-pressure thermogravimetric analyzer (HP-TGA) by injecting nitrogen and air to obtain the pyrolysis and oxidation responses. Kinetic analysis was performed using a first-order kinetic model discretizing thermal oxidation profiles in four different regions, namely, oxygen chemisorption (OC), decomposition of chemisorbed oxygen-based compounds (DCO), first combustion (FC), and second combustion (SC). As main results, it was obtained that the saturates were just described by FC and SC regions at all pressures, while aromatics and resins by the four stages (OC, DCO, FC, and SC) for pressures higher than 3.0 MPa. At 6.0 MPa, aromatics exhibit a rapid consumption in the FC region, while resins present a more controlled consumption, distributed in the three decomposition regions. This implies that as pressure increases, aromatics have a greater influence on oxidation reactions at high temperatures. From pyrolysis curves, it was noted that the amount of coke generated follows the increasing order saturates

Crude oil spills are of global concern because of their potential to cause massive water pollution and the destruction of aquatic life. The current technologies for oil spill cleanup only focus on impact mitigation and ignore crude oil recovery. There is therefore a need for an innovative technology that generates materials with crude oil recovery capabilities. Since manufactured materials have shown promising capabilities for recovering crude oil and treating water at the same time, this study examines and develops a strategy for manufacturing magnetic hexagonal boron nitride (h-BN) nanostructured composites—a high-performance material that can be used to both clean water and recover crude oil for further use after a crude oil spill. This manufacturing technique is unique as it consists of a single step and contemplates h-BN synthesis at 1300 K compared to 2275 K used previously. The material produced is capable of absorbing crude oil up to 53 times its own weight, employing only a magnetic field for the...

Foams in the oil and gas industry have been used as divergent fluids to attenuate the fluid channeling in high-permeability zones. Commonly, foams are generated using a surfactant solution in high-permeability reservoirs, which exhibit stability problems. Therefore, the main objective of this study is to stabilize the foams by the addition of modified silica nanoparticles, varying the surface acidity and polarity for natural gas flooding in tight gas-condensated reservoirs. Four types of modified silica-based nanoparticles with varying surface acidity and polarity (coated with vacuum residue) were synthesized and evaluated using surfactant adsorption. The basic nanoparticles exhibited a greater adsorption capacity of the surfactant, reaching an adsorbed amount of approximately 200 mg of surfactant per gram of nanoparticles, and Type I adsorption behavior. Foams were generated and evaluated based on their stability using two routes, namely, (1) with mechanical agitation and (2) methane flooding, to determi...

Pyrolysis and oxidation of asphaltene-born coke-like residue formed onto ex situ and in situ prepared NiO nanoparticles as initial steps toward developing advanced in situ combustion enhanced oil recovery (EOR) processes were studied. The in situ synthesized NiO nanoparticles in heavy oil matrix, containing coke-like residue, were characterized by X-ray diffraction, Brunauer–Emmett–Teller, field-emission scanning electron microscopy, and energy-dispersive X-ray mapping techniques. The pyrolysis and postpyrolysis oxidation of the coke residue were investigated by temperature-programmed pyrolysis (TPP) and temperature-programmed oxidation (TPO) methods, respectively. Oxidation kinetics of the coke residue was described by the Kissinger–Akahira–Sunose isoconversional method. The results showed a higher percentage of coke residue on the in situ prepared nanoparticles than the ex situ employed ones. Eventually, during the TPP of the coke residue, the amount of carbon oxides released per total amount of the cok...