scholarly journals Effect of Computational Schemes on Coupled Flow and Geo-Mechanical Modeling of CO2 Leakage through a Compromised Well

Computation ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 98
Author(s):  
Mohammad Islam ◽  
Nicolas Huerta ◽  
Robert Dilmore
Keyword(s):  
Aqueous Phase ◽  
Heterogeneous Media ◽  
Solid Phase ◽  
Spatial Domain ◽  
Heterogeneous Porous Media ◽  
Benchmark Problems ◽  
Coupled Flow ◽  
Fe Method ◽  
Mass Lumping ◽  
Sequential Coupling

Carbon capture, utilization, and storage (CCUS) describes a set of technically viable processes to separate carbon dioxide (CO2) from industrial byproduct streams and inject it into deep geologic formations for long-term storage. Legacy wells located within the spatial domain of new injection and production activities represent potential pathways for fluids (i.e., CO2 and aqueous phase) to leak through compromised components (e.g., through fractures or micro-annulus pathways). The finite element (FE) method is a well-established numerical approach to simulate the coupling between multi-phase fluid flow and solid phase deformation interactions that occur in a compromised well system. We assumed the spatial domain consists of a three-phases system: a solid, liquid, and gas phase. For flow in the two fluids phases, we considered two sets of primary variables: the first considering capillary pressure and gas pressure (PP) scheme, and the second considering liquid pressure and gas saturation (PS) scheme. Fluid phases were coupled with the solid phase using the full coupling (i.e., monolithic coupling) and iterative coupling (i.e., sequential coupling) approaches. The challenge of achieving numerical stability in the coupled formulation in heterogeneous media was addressed using the mass lumping and the upwinding techniques. Numerical results were compared with three benchmark problems to assess the performance of coupled FE solutions: 1D Terzaghi’s consolidation, Liakopoulos experiments, and the Kueper and Frind experiments. We found good agreement between our results and the three benchmark problems. For the Kueper and Frind test, the PP scheme successfully captured the observed experimental response of the non-aqueous phase infiltration, in contrast to the PS scheme. These exercises demonstrate the importance of fluid phase primary variable selection for heterogeneous porous media. We then applied the developed model to the hypothetical case of leakage along a compromised well representing a heterogeneous media. Considering the mass lumping and the upwinding techniques, both the monotonic and the sequential coupling provided identical results, but mass lumping was needed to avoid numerical instabilities in the sequential coupling. Additionally, in the monolithic coupling, the magnitude of primary variables in the coupled solution without mass lumping and the upwinding is higher, which is essential for the risk-based analyses.

Methodology of Research in Micropollutants – Heavy Metals

1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast
Keyword(s):  
Heavy Metals ◽  
Mathematical Models ◽  
Aqueous Phase ◽  
Suspended Matter ◽  
Solid Phase ◽  
Aquatic Organisms ◽  
Biological Processes ◽  
Particulate Phase ◽  
Sources Of Pollution ◽  
Adsorption Desorption

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.

scholarly journals A mathematical approach to Ostwald ripening due to diffusion and deformation in liquid bridge

2013 ◽  
Vol 45 (3) ◽  
pp. 261-271 ◽  
Author(s):  
B. Randjelovic ◽  
K. Shinagawa ◽  
Z.S. Nikolic
Keyword(s):  
Liquid Phase ◽  
Liquid Bridge ◽  
Ostwald Ripening ◽  
Solid Phase ◽  
Liquid Phase Sintering ◽  
Solute Diffusion ◽  
Deformation Analysis ◽  
Mathematical Approach ◽  
Fe Method ◽  
Grain Coarsening

From many experiments with mixtures of small and large grains, it can be concluded that during liquid phase sintering, smaller grains partially dissolve and a solid phase precipitates on the larger grains and grain coarsening occurs. The growth rate can be controlled either by the solid-liquid phase boundary reaction or by diffusion through the liquid phase. The microstructure may change either by larger grains growing during the Ostwald ripening process or by shape accommodation. In this study, two-dimensional mathematical approach for simulation of grain coarsening by grain boundary migration based on a physical and corresponding numerical modeling of liquid phase sintering will be considered. A combined mathematical method of analyzing viscous deformation and solute diffusion in liquid bridge between two grains with different sizes will be proposed. The viscous FE method will be used for calculating meniscus of the liquid bridge, with the interfacial tensions taken into consideration. The FE method for diffusion will be also implemented by using the same mesh as the deformation analysis.

scholarly journals The influence of Fe(III) and Mn(IV) on the biotransformation of hydrocarbons in groundwater

2019 ◽  
pp. 21-31
Author(s):  
N. K. Fisher
Keyword(s):  
River Basin ◽  
Aqueous Phase ◽  
Solid Phase ◽  
Close Correlation ◽  
Electron Acceptors ◽  
Amur River Basin ◽  
Geochemical Background ◽  
Amur River ◽  
Kinetic Factor ◽  
Microbiological Processes

According to the thermodynamic ladder, microorganisms in groundwater use electron acceptors consistently – for transformation of pollution from the pollution plume edge to its core. However, some researchers come to the conclusion that only methanogenic biotransformation of pollution or reduction of Fe(III) and Mn(IV) from the solid phase can occur in the plume, and due to the kinetic factor microorganisms use electron acceptors from the aqueous phase (O2, NO3- и SO42-) only on the edge of the pollution plume. The purpose of the research was to determine whether microorganisms use Fe(III) and Mn(IV) as acceptors of electrons for hydrocarbons transformation in groundwater in the northern part of the Middle Heilongjiang-Amur River basin aquifer. In the study area, both lenses of petroleum-hydrocarbons (non-aqueous phase liquids) on the surface of groundwater (up to 2.5 m) and high concentrations of dissolved hydrocarbons (up to 1000 mg/l) are noted. Microbiological processes were assessed in situ by the method of geochemical indicators. The most active biogeochemical processes occurred during the spring-summer rise of groundwater level. The seasonal increasing of level led to the entry of Fe(III) and Mn(IV) into the pollution plume and activation of the microbiological processes of its reduction. Microorganisms mostly use electron acceptors from the solid phase – Fe(III) and Mn(IV), but not NO3, SO42 from the aqueous phase. This is confirmed by the close correlation of HCO3- formation and that of Fe(II) and Mn(II) in groundwater (r2 up to 0.93). This says that for the groundwater self-purification the kinetic factor rather than thermodynamic one is decisive; and microorganisms use electron acceptors that are currently available. As a result of microbiological pollution destruction, the content of Fe(II) in groundwater increased up to 100 mg/l, Mn (II) – up to 16 mg/l, which exceeds the natural background 4 and 8 times, respectively. This was also because the regional geochemical background of the study area (Amur River basin) forms Fe and Mn.

Aqueous-Phase Synthesis and Solid-Phase Fluorescence of 3-(Methoxyphenyl)-2-cyanoacrylamides

2018 ◽  
Vol 54 (7) ◽  
pp. 1100-1102 ◽  
Author(s):  
D. A. Bezgin ◽  
O. V. Ershov ◽  
M. Yu. Ievlev ◽  
M. Yu. Belikov ◽  
I. N. Bardasov
Keyword(s):  
Aqueous Phase ◽  
Solid Phase ◽  
Phase Synthesis

scholarly journals Chemical characterization of the main products formed through aqueous-phase photonitration of guaiacol

2014 ◽  
Vol 7 (8) ◽  
pp. 2457-2470 ◽  
Author(s):  
Z. Kitanovski ◽  
A. Čusak ◽  
I. Grgić ◽  
M. Claeys
Keyword(s):  
Aqueous Phase ◽  
Atmospheric Aerosols ◽  
High Performance ◽  
Solid Phase ◽  
Chemical Characterization ◽  
Heterogeneous Reactions ◽  
Negative Ion ◽  
Reaction Products ◽  
Esi Ms

Abstract. Guaiacol (2-methoxyphenol) and its derivatives can be emitted into the atmosphere by thermal degradation (i.e., burning) of wood lignins. Due to its volatility, guaiacol is predominantly distributed atmospherically in the gaseous phase. Recent studies have shown the importance of aqueous-phase reactions in addition to the dominant gas-phase and heterogeneous reactions of guaiacol, in the formation of secondary organic aerosol (SOA) in the atmosphere. The main objectives of the present study were to chemically characterize the main products of the aqueous-phase photonitration of guaiacol and examine their possible presence in urban atmospheric aerosols. The aqueous-phase reactions were carried out under simulated sunlight and in the presence of hydrogen peroxide and nitrite. The formed guaiacol reaction products were concentrated by solid-phase extraction and then purified with semi-preparative high-performance liquid chromatography (HPLC). The fractionated individual compounds were isolated as pure solids and further analyzed with liquid-state proton, carbon-13 and two-dimensional nuclear magnetic resonance (NMR) spectroscopy, and direct infusion negative ion electrospray ionization tandem mass spectrometry ((−)ESI-MS/MS). The NMR and product ion (MS2) spectra were used for unambiguous product structure elucidation. The main products of guaiacol photonitration are 4-nitroguaiacol (4NG), 6-nitroguaiacol (6NG), and 4,6-dinitroguaiacol (4,6DNG). Using the isolated compounds as standards, 4NG and 4,6DNG were unambiguously identified in winter PM10 aerosols from the city of Ljubljana (Slovenia) by means of HPLC/(−)ESI-MS/MS. Owing to the strong absorption of ultraviolet and visible light, 4,6DNG could be an important constituent of atmospheric "brown" carbon, especially in regions affected by biomass burning.

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