Joachim Moortgat - Profile on Academia.edu (original) (raw)

Papers by Joachim Moortgat

Hydro-Thermodynamically Driven Fluid Mixing Across Phases in Porous Media

AGUFM, Dec 1, 2016

Kinetic emission of shale gas in saline water: Insights from experimental observation of gas shale in canister desorption testing

Fuel, Sep 1, 2021

Abstract Gas-in-place (GIP) is a significant parameter in the assessment of gas resources and res... more Abstract Gas-in-place (GIP) is a significant parameter in the assessment of gas resources and reserves, design of production strategy, and enhanced gas recovery. To precisely estimate GIP of shales, a direct method often sums experimentally measured desorbed gas by canister desorption testing (CDT), predicted lost gas in the recovery of the fresh core via CDT data in situ on the surface, and measured residual gas in the lab. However, the critical kinetic emission behavior remains poorly understood. A series of CDTs were collected from our previous work on 33 fresh shale cores. This work, based on experimental observation, proposes a Quasi-Langmuir model, which well fits the experimentally measured data with a coefficient of determination, R 2 , up to 0.9992. We also compare the model to 5 other potential kinetic gas sorption models, including Pseudo First Order (PFO), Bangham, Elovich, Ritchie, and Pseudo Second Order (PSO) models in terms of the proposed relationship between changes of emitted gas and time. Results show that the Quasi-Langmuir model fits the kinetic data best, followed by Bangham, Ritchie, PSO, PFO, and Elovich models. Ritchie and PSO models give comparable fittings, and the Elovich model deviates from measured data far more than other models. This work improves understanding of the emission behavior and process of shale gas in CDT, which will provide a robust estimation of lost gas in the borehole, and a more accurate GIP estimate for production in the petroleum industry. Results from this work have significant implications for monitoring the treatment of water and air contamination based on adsorption.

Energy & Fuels, Mar 2, 2016

Numerical modeling of asphaltene precipitation in petroleum reservoirs is important in relation t... more Numerical modeling of asphaltene precipitation in petroleum reservoirs is important in relation to possible precipitation around the wellbore in the producing well. Production from some reservoirs results in asphaltene precipitation in the wellbore region, leading to productivity loss and need for cleanup. Fluid injection even when there is asphaltene precipitation may not lead to injectivity loss. There are desirable processes in which precipitation of asphaltenes can lead to "in situ" upgrading of heavy oil recovery. Reservoir compositional models that are currently in use rely on cubic equations of state for asphaltene precipitation. The cubic equations, despite their relative reliability in describing reservoir fluids' phase behavior, become unreliable in asphaltene-rich phase description. A number of noncubic equations of state have been introduced to overcome the shortcomings of cubic equations. The cubic-plus-association equation of state (CPA-EOS) is perhaps the method of choice in representing asphaltenes in compositional modeling. When the hydrocarbon fluids do not contain asphaltenes, CPA-EOS reduces to the standard cubic equation. In this work, we implement CPA-EOS in compositional modeling and introduce a simple technique to speed up considerably the root finding of the CPA-EOS. Our efficient algorithm reduces significantly the additional computational cost from the incorporation of the CPA-EOS. We also derive the basic equations for the total compressibility and total partial molar volume in our implementation of the CPA-EOS compositional modeling. We present three numerical examples for CO 2 injection in 2D and 3D domains saturated with Weyburn oil and show results of asphaltene-rich phase saturation among other predictions. This work introduces a general framework for widespread use of CPA-EOS in compositional modeling in three-phase flows of gas, light liquid, and asphaltene-rich phases.

Poromechanics of Multiphase Multicomponent Compositional Flow and Transport

AGU Fall Meeting Abstracts, Dec 1, 2019

Bulletin of the American Physical Society, Nov 21, 2016

Thermodynamically Consistent Fluid Mixing in Porous Media Induced by Viscous Fingering and Channe... more Thermodynamically Consistent Fluid Mixing in Porous Media Induced by Viscous Fingering and Channeling of Multiphase Flow MOHAM-MAD AMIN AMOOIE, MOHAMMAD REZA SOLTANIAN , JOACHIM MOORT-GAT, The Ohio State University -Fluid mixing and its interplay with viscous fingering as well as flow channeling through heterogeneous media have been traditionally studied for fully (im)miscible conditions in which a (two-) single-phase system is represented by two components, e.g. a solvent and a solute, with (zero) infinite mutual solubility. However, many subsurface problems, e.g. gas injection/migration in hydrocarbon reservoirs, involve multiple species transfer. Multicomponent fluid properties behave non-linearly, through an equation of state, as a function of temperature, pressure, and compositions. Depending on the minimum miscibility pressure, a two-phase region with finite, non-zero mutual solubility may develop, e.g. in a partially-miscible system. Here we study mixing of fluids with partial mutual solubility, induced by viscous flow fingering, channeling, and species transport within and between phases. We uncover non-linear mixing dynamics of a finite-size slug of a less viscous fluid attenuated by a carrier fluid during rectilinear displacement. We perform accurate numerical simulations that are thermodynamically-consistent to capture fingering patterns and complex phase behavior of mixtures. The results provide a broad perspective into how multiphase flow can alter fluid mixing in porous media.

International Journal of Multiphase Flow, Aug 1, 2018

We present continuum-scale modeling of multiphase compressible flow in porous media with applicat... more We present continuum-scale modeling of multiphase compressible flow in porous media with applications to hydrocarbon reservoir engineering. A new black-oil model is developed and compared with a fully compositional simulator to model the thermodynamic phase behavior. In the context of black-oil modeling, where components are lumped into a gas and liquid pseudocomponent with only the gas transferring between liquid and gas phases, we allow for a variable bubble point pressure (e.g., when gas enters an undersaturated zone). Traditionally, a primary variable switching strategy has been used, which is known to be prone to convergence and phase identification issues. Instead, we adopt an overall molar composition-based framework that can robustly model phase appearance or disappearance. Phase properties across a broad range of pressures for different black-oil compositions are constructed from compositional phase split calculations to correctly model the phase transition. Mass transport is updated explicitly by a locally mass conserving multilinear discontinuous Galerkin method. Globally continuous pressure and velocity fields are obtained through an implicit mixed hybrid FE scheme. The robustness and accuracy of our FE simulator are demonstrated in several problems, where we have attained considerable speed-up and maintained the accuracy with the new black-oil model.

RETRACTED: The shale gas sorption capacity of transitional shales in the Ordos Basin, NW China

Fuel, Nov 1, 2017

Abstract A series of methane sorption experiments were conducted at reservoir temperature, 60 ° C... more Abstract A series of methane sorption experiments were conducted at reservoir temperature, 60 ° C and pressures up to 18 MPa for seven fresh, over mature Lower Permian-Upper Carboniferous shale core samples collected from the Ordos Basin with depths over 3000 m and TOCs ranging 0.49–3.82 wt%. The measured maxima of excess sorption capacity of methane range from 1.36 to 2.38 m 3 /t. Maximum sorption capacity did not correlate only with total organic carbon (TOC) but showed a more complex dependence on petrophysical and mineralogical properties. Three different models were investigated to match the measured excess sorption isotherms and to correct those to absolute sorption isotherms: the 1) Ono-Kondo (OK), 2) supercritical Dubinin-Radushkevich (SDR) and 3) Langmuir-based excess sorption models. All three models are found to match the experimental data with comparable accuracy and to agree on the correction to absolute sorption isotherms. The relationship between sorbed gas and depth is also investigated based on a combination of sorbed gas data from previous research and from this investigation. A theoretical model is proposed to predict the evolution of methane sorption capacity with burial depth (or time) as a function of TOC, vitrinite reflectance (Ro), type of kerogen, pressure and temperature. The results show that methane sorption capacity will first increase with depth, and then decrease with depth after reaching a critical depth.

Abstracts with programs, 2017

Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both... more Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both organic and inorganic grains develop micro-, meso-and macropores in gas window. Clay minerals control specific surface area and absorbed gas at over-mature stage. High TOC increases micropore volume at high depth, while total pore volume decreases.

Gravitational Wave Interaction with Gamma-Ray Burst Plasma

IAUJD, 2003

ABSTRACT

Viscosification of CO2 to improve subsurface storage — A modeling study

International Journal of Greenhouse Gas Control

EarthArXiv (California Digital Library), Dec 28, 2022

This paper has been published in Remote Sensing of Environment under CC-BY-NC-ND license.

Text-SI-Amooie et al-2017-Geophysical_Research_Letters

Towards A Fully Compositional Mixing Model: Viscous Flow Instabilities in Different Levels of Miscibility and Fluid-Rock Heterogeneities

Chemical Engineering Journal, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Coal Geology, 2018

Pore connectivity is one of the most important characteristics of shale reservoirs because it sig... more Pore connectivity is one of the most important characteristics of shale reservoirs because it significantly impacts the effective pore space, the fluid migration, and the gas production. In this work, pore connectivity and its primary controlling factors were investigated using a combination of field emission-scanning electron microscopy (FE-SEM), focused ion beam-scanning electron microscopy (FIB-SEM), mercury intrusion porosimetry (MIP), and nuclear magnetic resonance (NMR). The results show that using the difference between NMR and MIP is a reliable method to characterize pore connectivity. NMR pore size distribution (PSD) curves converted from T 2 spectra, and MIP PSD curves were observed to have consistent shapes. The amplitude of NMR PSD curves is higher than that of MIP PSD curves for S-group pores (<200 nm), while the relationship is opposite for L-group pores (200 nm-10μm), which may be due to the permeability of shale. A low permeability allows a smaller amount of mercury to intrude into the small pores. Based on experimental results, the pores of 8-20 nm make a contribution of 5%-11% to pore connectivity, whereas the pores of 200-700 nm are mainly interparticle pores and microfissures, contributing from 38% to 72% of pore connectivity. Stratification and pore morphology in the Lower Cambrian Wangyinpu and Guanyintang shales in the Xiuwu Basin are the two critical influencing factors of pore connectivity. The pore connectivity of well-laminated shale is higher than that of less-laminated shale. The laminated structures are usually composed of argillaceous and siliceous lamina, which tend to give rise to fissures during hydrocarbon generation or under confining stress. As a result, the pores around the microfissures are more likely to be communicating. Shales with the structure of uniformly distributed organic and inorganic minerals have the best pore connectivity. Both the interparticle pores and microfissures between organic matter and inorganic minerals or between inorganic minerals can effectively connect organic pore networks and greatly improve the pore connectivity.

Fuel, 2017

Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both... more Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both organic and inorganic grains develop micro-, meso-and macropores in gas window. Clay minerals control specific surface area and absorbed gas at over-mature stage. High TOC increases micropore volume at high depth, while total pore volume decreases.

Stochastic Environmental Research and Risk Assessment, 2017

This paper presents a stochastic model for multicomponent competitive monovalent cation exchange ... more This paper presents a stochastic model for multicomponent competitive monovalent cation exchange in hierarchical porous media. Reactive transport in porous media is highly sensitive to heterogeneities in physical and chemical properties, such as hydraulic conductivity (K), and cation exchange capacity (CEC). We use a conceptual model for multimodal reactive mineral facies and develop a Eulerian-based stochastic theory to analyze the transport of multiple cations in heterogeneous media with a hierarchical organization of reactive minerals. Numerical examples investigate the retardation factors and dispersivities in a chemical system made of three monovalent cations (Na ? , K ? , and Cs ? ). The results demonstrate how heterogeneity influences the transport of competitive monovalent cations, and highlight the importance of correlations between K and CEC. Further sensitivity analyses are presented investigating how the dispersion and retardation of each cation are affected by the means, variances, and integral scales of K and CEC. The volume fraction of organic matter is shown to be another important parameter. The Eulerian stochastic framework presented in this work clarifies the importance of each system parameters on the migration of cation plumes in formations with hierarchical organization of facies types. Our stochastic approach could be used as an alternative to numerical simulations for 3D reactive transport in hierarchical porous media, which become prohibitively expensive for the multicomponent applications considered in this work.

Gravitational Wave Interaction with Gamma-Ray Burst Plasma

ABSTRACT

Remote Sensing of Environment

Sub-meter-resolution satellite imagery is used to track river extents • Convolutional neural netw... more Sub-meter-resolution satellite imagery is used to track river extents • Convolutional neural networks can detect water with over 90% accuracy • Even panchromatic images allow accurate water detection • Multiple FCN are adapted for satellite imagery and evaluated for performance

Lithosphere

Organic matter (OM) pores are widely considered to be important for gas storage and transportatio... more Organic matter (OM) pores are widely considered to be important for gas storage and transportation. In this work, we quantitatively analyze the pore structure of OM and its controlling factors through geochemical and petrologic analyses, optical microscope, OM isolation, and adsorption isotherms. These analyses were carried out on lacustrine shale samples from the Lower Cretaceous Shahezi Formation, which is located in the Changling Fault Depression in Songliao Basin. The results show that the content of soluble OM (SOM) is low, accounting for 0.26%-3.75% of total OM. The contribution of pore development from SOM itself is limited. After extraction of SOM by chloroform, pore volume (PV), specific surface area (SSA), and average pore diameter (APD) exposed to gas molecules greatly increase. The existence of SOM has an obvious effect on pores of >10 nm, especially the clay mineral-related pores that contribute the most to the total PV. The content of kerogen is higher than SOM and ...

Hydro-Thermodynamically Driven Fluid Mixing Across Phases in Porous Media

AGUFM, Dec 1, 2016

Kinetic emission of shale gas in saline water: Insights from experimental observation of gas shale in canister desorption testing

Fuel, Sep 1, 2021

Abstract Gas-in-place (GIP) is a significant parameter in the assessment of gas resources and res... more Abstract Gas-in-place (GIP) is a significant parameter in the assessment of gas resources and reserves, design of production strategy, and enhanced gas recovery. To precisely estimate GIP of shales, a direct method often sums experimentally measured desorbed gas by canister desorption testing (CDT), predicted lost gas in the recovery of the fresh core via CDT data in situ on the surface, and measured residual gas in the lab. However, the critical kinetic emission behavior remains poorly understood. A series of CDTs were collected from our previous work on 33 fresh shale cores. This work, based on experimental observation, proposes a Quasi-Langmuir model, which well fits the experimentally measured data with a coefficient of determination, R 2 , up to 0.9992. We also compare the model to 5 other potential kinetic gas sorption models, including Pseudo First Order (PFO), Bangham, Elovich, Ritchie, and Pseudo Second Order (PSO) models in terms of the proposed relationship between changes of emitted gas and time. Results show that the Quasi-Langmuir model fits the kinetic data best, followed by Bangham, Ritchie, PSO, PFO, and Elovich models. Ritchie and PSO models give comparable fittings, and the Elovich model deviates from measured data far more than other models. This work improves understanding of the emission behavior and process of shale gas in CDT, which will provide a robust estimation of lost gas in the borehole, and a more accurate GIP estimate for production in the petroleum industry. Results from this work have significant implications for monitoring the treatment of water and air contamination based on adsorption.

Energy & Fuels, Mar 2, 2016

Numerical modeling of asphaltene precipitation in petroleum reservoirs is important in relation t... more Numerical modeling of asphaltene precipitation in petroleum reservoirs is important in relation to possible precipitation around the wellbore in the producing well. Production from some reservoirs results in asphaltene precipitation in the wellbore region, leading to productivity loss and need for cleanup. Fluid injection even when there is asphaltene precipitation may not lead to injectivity loss. There are desirable processes in which precipitation of asphaltenes can lead to "in situ" upgrading of heavy oil recovery. Reservoir compositional models that are currently in use rely on cubic equations of state for asphaltene precipitation. The cubic equations, despite their relative reliability in describing reservoir fluids' phase behavior, become unreliable in asphaltene-rich phase description. A number of noncubic equations of state have been introduced to overcome the shortcomings of cubic equations. The cubic-plus-association equation of state (CPA-EOS) is perhaps the method of choice in representing asphaltenes in compositional modeling. When the hydrocarbon fluids do not contain asphaltenes, CPA-EOS reduces to the standard cubic equation. In this work, we implement CPA-EOS in compositional modeling and introduce a simple technique to speed up considerably the root finding of the CPA-EOS. Our efficient algorithm reduces significantly the additional computational cost from the incorporation of the CPA-EOS. We also derive the basic equations for the total compressibility and total partial molar volume in our implementation of the CPA-EOS compositional modeling. We present three numerical examples for CO 2 injection in 2D and 3D domains saturated with Weyburn oil and show results of asphaltene-rich phase saturation among other predictions. This work introduces a general framework for widespread use of CPA-EOS in compositional modeling in three-phase flows of gas, light liquid, and asphaltene-rich phases.

Poromechanics of Multiphase Multicomponent Compositional Flow and Transport

AGU Fall Meeting Abstracts, Dec 1, 2019

Bulletin of the American Physical Society, Nov 21, 2016

Thermodynamically Consistent Fluid Mixing in Porous Media Induced by Viscous Fingering and Channe... more Thermodynamically Consistent Fluid Mixing in Porous Media Induced by Viscous Fingering and Channeling of Multiphase Flow MOHAM-MAD AMIN AMOOIE, MOHAMMAD REZA SOLTANIAN , JOACHIM MOORT-GAT, The Ohio State University -Fluid mixing and its interplay with viscous fingering as well as flow channeling through heterogeneous media have been traditionally studied for fully (im)miscible conditions in which a (two-) single-phase system is represented by two components, e.g. a solvent and a solute, with (zero) infinite mutual solubility. However, many subsurface problems, e.g. gas injection/migration in hydrocarbon reservoirs, involve multiple species transfer. Multicomponent fluid properties behave non-linearly, through an equation of state, as a function of temperature, pressure, and compositions. Depending on the minimum miscibility pressure, a two-phase region with finite, non-zero mutual solubility may develop, e.g. in a partially-miscible system. Here we study mixing of fluids with partial mutual solubility, induced by viscous flow fingering, channeling, and species transport within and between phases. We uncover non-linear mixing dynamics of a finite-size slug of a less viscous fluid attenuated by a carrier fluid during rectilinear displacement. We perform accurate numerical simulations that are thermodynamically-consistent to capture fingering patterns and complex phase behavior of mixtures. The results provide a broad perspective into how multiphase flow can alter fluid mixing in porous media.

International Journal of Multiphase Flow, Aug 1, 2018

We present continuum-scale modeling of multiphase compressible flow in porous media with applicat... more We present continuum-scale modeling of multiphase compressible flow in porous media with applications to hydrocarbon reservoir engineering. A new black-oil model is developed and compared with a fully compositional simulator to model the thermodynamic phase behavior. In the context of black-oil modeling, where components are lumped into a gas and liquid pseudocomponent with only the gas transferring between liquid and gas phases, we allow for a variable bubble point pressure (e.g., when gas enters an undersaturated zone). Traditionally, a primary variable switching strategy has been used, which is known to be prone to convergence and phase identification issues. Instead, we adopt an overall molar composition-based framework that can robustly model phase appearance or disappearance. Phase properties across a broad range of pressures for different black-oil compositions are constructed from compositional phase split calculations to correctly model the phase transition. Mass transport is updated explicitly by a locally mass conserving multilinear discontinuous Galerkin method. Globally continuous pressure and velocity fields are obtained through an implicit mixed hybrid FE scheme. The robustness and accuracy of our FE simulator are demonstrated in several problems, where we have attained considerable speed-up and maintained the accuracy with the new black-oil model.

RETRACTED: The shale gas sorption capacity of transitional shales in the Ordos Basin, NW China

Fuel, Nov 1, 2017

Abstract A series of methane sorption experiments were conducted at reservoir temperature, 60 ° C... more Abstract A series of methane sorption experiments were conducted at reservoir temperature, 60 ° C and pressures up to 18 MPa for seven fresh, over mature Lower Permian-Upper Carboniferous shale core samples collected from the Ordos Basin with depths over 3000 m and TOCs ranging 0.49–3.82 wt%. The measured maxima of excess sorption capacity of methane range from 1.36 to 2.38 m 3 /t. Maximum sorption capacity did not correlate only with total organic carbon (TOC) but showed a more complex dependence on petrophysical and mineralogical properties. Three different models were investigated to match the measured excess sorption isotherms and to correct those to absolute sorption isotherms: the 1) Ono-Kondo (OK), 2) supercritical Dubinin-Radushkevich (SDR) and 3) Langmuir-based excess sorption models. All three models are found to match the experimental data with comparable accuracy and to agree on the correction to absolute sorption isotherms. The relationship between sorbed gas and depth is also investigated based on a combination of sorbed gas data from previous research and from this investigation. A theoretical model is proposed to predict the evolution of methane sorption capacity with burial depth (or time) as a function of TOC, vitrinite reflectance (Ro), type of kerogen, pressure and temperature. The results show that methane sorption capacity will first increase with depth, and then decrease with depth after reaching a critical depth.

Abstracts with programs, 2017

Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both... more Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both organic and inorganic grains develop micro-, meso-and macropores in gas window. Clay minerals control specific surface area and absorbed gas at over-mature stage. High TOC increases micropore volume at high depth, while total pore volume decreases.

Gravitational Wave Interaction with Gamma-Ray Burst Plasma

IAUJD, 2003

ABSTRACT

Viscosification of CO2 to improve subsurface storage — A modeling study

International Journal of Greenhouse Gas Control

EarthArXiv (California Digital Library), Dec 28, 2022

This paper has been published in Remote Sensing of Environment under CC-BY-NC-ND license.

Text-SI-Amooie et al-2017-Geophysical_Research_Letters

Towards A Fully Compositional Mixing Model: Viscous Flow Instabilities in Different Levels of Miscibility and Fluid-Rock Heterogeneities

Chemical Engineering Journal, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Coal Geology, 2018

Pore connectivity is one of the most important characteristics of shale reservoirs because it sig... more Pore connectivity is one of the most important characteristics of shale reservoirs because it significantly impacts the effective pore space, the fluid migration, and the gas production. In this work, pore connectivity and its primary controlling factors were investigated using a combination of field emission-scanning electron microscopy (FE-SEM), focused ion beam-scanning electron microscopy (FIB-SEM), mercury intrusion porosimetry (MIP), and nuclear magnetic resonance (NMR). The results show that using the difference between NMR and MIP is a reliable method to characterize pore connectivity. NMR pore size distribution (PSD) curves converted from T 2 spectra, and MIP PSD curves were observed to have consistent shapes. The amplitude of NMR PSD curves is higher than that of MIP PSD curves for S-group pores (<200 nm), while the relationship is opposite for L-group pores (200 nm-10μm), which may be due to the permeability of shale. A low permeability allows a smaller amount of mercury to intrude into the small pores. Based on experimental results, the pores of 8-20 nm make a contribution of 5%-11% to pore connectivity, whereas the pores of 200-700 nm are mainly interparticle pores and microfissures, contributing from 38% to 72% of pore connectivity. Stratification and pore morphology in the Lower Cambrian Wangyinpu and Guanyintang shales in the Xiuwu Basin are the two critical influencing factors of pore connectivity. The pore connectivity of well-laminated shale is higher than that of less-laminated shale. The laminated structures are usually composed of argillaceous and siliceous lamina, which tend to give rise to fissures during hydrocarbon generation or under confining stress. As a result, the pores around the microfissures are more likely to be communicating. Shales with the structure of uniformly distributed organic and inorganic minerals have the best pore connectivity. Both the interparticle pores and microfissures between organic matter and inorganic minerals or between inorganic minerals can effectively connect organic pore networks and greatly improve the pore connectivity.

Fuel, 2017

Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both... more Pore structure of transitional shale and organic matter is measured by N 2 , CO 2 isotherms. Both organic and inorganic grains develop micro-, meso-and macropores in gas window. Clay minerals control specific surface area and absorbed gas at over-mature stage. High TOC increases micropore volume at high depth, while total pore volume decreases.

Stochastic Environmental Research and Risk Assessment, 2017

This paper presents a stochastic model for multicomponent competitive monovalent cation exchange ... more This paper presents a stochastic model for multicomponent competitive monovalent cation exchange in hierarchical porous media. Reactive transport in porous media is highly sensitive to heterogeneities in physical and chemical properties, such as hydraulic conductivity (K), and cation exchange capacity (CEC). We use a conceptual model for multimodal reactive mineral facies and develop a Eulerian-based stochastic theory to analyze the transport of multiple cations in heterogeneous media with a hierarchical organization of reactive minerals. Numerical examples investigate the retardation factors and dispersivities in a chemical system made of three monovalent cations (Na ? , K ? , and Cs ? ). The results demonstrate how heterogeneity influences the transport of competitive monovalent cations, and highlight the importance of correlations between K and CEC. Further sensitivity analyses are presented investigating how the dispersion and retardation of each cation are affected by the means, variances, and integral scales of K and CEC. The volume fraction of organic matter is shown to be another important parameter. The Eulerian stochastic framework presented in this work clarifies the importance of each system parameters on the migration of cation plumes in formations with hierarchical organization of facies types. Our stochastic approach could be used as an alternative to numerical simulations for 3D reactive transport in hierarchical porous media, which become prohibitively expensive for the multicomponent applications considered in this work.

Gravitational Wave Interaction with Gamma-Ray Burst Plasma

ABSTRACT

Remote Sensing of Environment

Sub-meter-resolution satellite imagery is used to track river extents • Convolutional neural netw... more Sub-meter-resolution satellite imagery is used to track river extents • Convolutional neural networks can detect water with over 90% accuracy • Even panchromatic images allow accurate water detection • Multiple FCN are adapted for satellite imagery and evaluated for performance

Lithosphere

Organic matter (OM) pores are widely considered to be important for gas storage and transportatio... more Organic matter (OM) pores are widely considered to be important for gas storage and transportation. In this work, we quantitatively analyze the pore structure of OM and its controlling factors through geochemical and petrologic analyses, optical microscope, OM isolation, and adsorption isotherms. These analyses were carried out on lacustrine shale samples from the Lower Cretaceous Shahezi Formation, which is located in the Changling Fault Depression in Songliao Basin. The results show that the content of soluble OM (SOM) is low, accounting for 0.26%-3.75% of total OM. The contribution of pore development from SOM itself is limited. After extraction of SOM by chloroform, pore volume (PV), specific surface area (SSA), and average pore diameter (APD) exposed to gas molecules greatly increase. The existence of SOM has an obvious effect on pores of >10 nm, especially the clay mineral-related pores that contribute the most to the total PV. The content of kerogen is higher than SOM and ...