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Dr. Hamid Nick
Technical University of Denmark

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0 Geothermal
0 Reservoir Simulation
0 reactive transport
0 flow in porous media
0 fractured rock

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Journal article
Published: 14 August 2021 in Journal of Petroleum Science and Engineering
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Fluid withdrawal and pore pressure reduction change the effective stresses around a borehole and cause borehole instability associated with progressive localisation of the damaged zone as well as potential fines production. Experimentally, chalk exhibits a complex geomechanics behaviour (pore collapse, shear failure, time/rate dependency) and modelling the behaviour of the borehole under in-situ and operational conditions requires the constitutive model to be capable of capturing the observations. This study presents a workflow that integrates rock mechanics testing on cylindrical specimens as well as specimen with a single lateral hole (SLH) and a finite element code, developed for chalk. The code incorporates post-peak softening as well as the rate dependency of the pore collapse stress in order to accurately predict the wellbore stability under in-situ stress conditions. The tested SLH specimen was CT imaged before and after testing for identifying the damaged zone and its extension. Backward numerical simulations of the SLH test data improved the accuracy of the estimated rock mechanics properties (post-peak failure and dilatancy) compared to the properties estimated by back analyses of standard triaxial tests with a single element simulator. The workflow is applied to predict the stability of a small lateral borehole (2 cm) created with Radial Jet Drilling technique with two different geometries: one with circular geometry created by a rotating nozzle; another with a circular hole with wing shaped cracks likely to develop when a static nozzle is used. Results of the wellbore stability analyses applying the chalk properties from the back analyses highlighted the importance of using experimentally verified post-peak failure and dilatancy parameters, together with a modelling tool capable of simulating shear strain localisation incorporating the Cosserat approach.

ACS Style

M.K. Medetbekova; M.R. Hajiabadi; A. Brovelli; H.F. Christensen; H.M. Nick. An integrated rock-mechanics tests and numerical modelling of chalk rocks: An improved integrated workflow for borehole safety. Journal of Petroleum Science and Engineering 2021, 208, 109365 .

AMA Style

M.K. Medetbekova, M.R. Hajiabadi, A. Brovelli, H.F. Christensen, H.M. Nick. An integrated rock-mechanics tests and numerical modelling of chalk rocks: An improved integrated workflow for borehole safety. Journal of Petroleum Science and Engineering. 2021; 208 ():109365.

Chicago/Turabian Style

M.K. Medetbekova; M.R. Hajiabadi; A. Brovelli; H.F. Christensen; H.M. Nick. 2021. "An integrated rock-mechanics tests and numerical modelling of chalk rocks: An improved integrated workflow for borehole safety." Journal of Petroleum Science and Engineering 208, no. : 109365.

Accepted manuscript
Published: 05 June 2021 in FEMS Microbiology Letters
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One of the major parameters that characterizes the kinetics of microbial processes is the maximum specific growth rate. The maximum specific growth rate for a single microorganism (${\mu _{max}}$) is fairly constant. However, a certain microbial process is typically catalyzed by a group of microorganisms (guild) that have various ${\mu _{max}}$ values. In many occasions, it is not feasible to breakdown a guild into its constituent microorganisms. Therefore, it is a common practice to assume a constant maximum specific growth rate for the guild ($\acute{\mu}_{max}$) and determine its value by fitting experimental data. This assumption is valid for natural environments, where microbial guilds are stabilized and dominated by microorganisms that grow optimally in those environments’ conditions. However, a change in an environment's conditions will trigger a community shift by favoring some of the microorganisms. This shift leads to a variable ${\acute{\mu}_{max}}$ as long as substrate availability is significantly higher than substrate affinity constant. In this work, it is illustrated that the assumption of constant ${\acute{\mu}_{max}}$ may underestimate or overestimate microbial growth. To circumvent this, a novel relationship that characterizes changes in ${\acute{\mu}_{max}}$ under abundant nutrient availability is proposed. The proposed relationship is evaluated for various random microbial guilds in batch experiments.

ACS Style

Moein Jahanbani Veshareh; Hamidreza M Nick. A novel relationship for the maximum specific growth rate of a microbial guild. FEMS Microbiology Letters 2021, 368, 1 .

AMA Style

Moein Jahanbani Veshareh, Hamidreza M Nick. A novel relationship for the maximum specific growth rate of a microbial guild. FEMS Microbiology Letters. 2021; 368 (12):1.

Chicago/Turabian Style

Moein Jahanbani Veshareh; Hamidreza M Nick. 2021. "A novel relationship for the maximum specific growth rate of a microbial guild." FEMS Microbiology Letters 368, no. 12: 1.

Correction
Published: 26 April 2021 in Mathematical Geosciences
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ACS Style

T. Kadeethum; S. Lee; H. M. Nick. Correction to: Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media. Mathematical Geosciences 2021, 53, 1095 -1095.

AMA Style

T. Kadeethum, S. Lee, H. M. Nick. Correction to: Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media. Mathematical Geosciences. 2021; 53 (5):1095-1095.

Chicago/Turabian Style

T. Kadeethum; S. Lee; H. M. Nick. 2021. "Correction to: Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media." Mathematical Geosciences 53, no. 5: 1095-1095.

Journal article
Published: 09 April 2021 in Computers & Geosciences
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This paper presents a mixed finite element framework for coupled hydro-mechanical–chemical processes in heterogeneous porous media. The framework combines two types of locally conservative discretization schemes: (1) an enriched Galerkin method for reactive flow, and (2) a three-field mixed finite element method for coupled fluid flow and solid deformation. This combination ensures local mass conservation, which is critical to flow and transport in heterogeneous porous media, with a relatively affordable computational cost. A particular class of the framework is constructed for calcite precipitation/dissolution reactions, incorporating their nonlinear effects on the fluid viscosity and solid deformation. Linearization schemes and algorithms for solving the nonlinear algebraic system are also presented. Through numerical examples of various complexity, we demonstrate that the proposed framework is a robust and efficient computational method for simulation of reactive flow and transport in deformable porous media, even when the material properties are strongly heterogeneous and anisotropic.

ACS Style

T. Kadeethum; S. Lee; F. Ballarin; J. Choo; H.M. Nick. A locally conservative mixed finite element framework for coupled hydro-mechanical-chemical processes in heterogeneous porous media. Computers & Geosciences 2021, 152, 104774 .

AMA Style

T. Kadeethum, S. Lee, F. Ballarin, J. Choo, H.M. Nick. A locally conservative mixed finite element framework for coupled hydro-mechanical-chemical processes in heterogeneous porous media. Computers & Geosciences. 2021; 152 ():104774.

Chicago/Turabian Style

T. Kadeethum; S. Lee; F. Ballarin; J. Choo; H.M. Nick. 2021. "A locally conservative mixed finite element framework for coupled hydro-mechanical-chemical processes in heterogeneous porous media." Computers & Geosciences 152, no. : 104774.

Journal article
Published: 25 March 2021 in Journal of Geophysical Research: Solid Earth
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The locus and shape of the yield surface of chalk in the stress space represent key input parameters in geomechanical models, as it dictates the onset and amount of plastic deformation. The study aims at reconstructing for the first time the initial end cap and shear failure line of intact reservoir chalk in plots of mean‐deviatoric stress vs. porosity. 137 stress‐strain measurements describe the effects of initial porosity between 30% and 45% and initial water saturation on the yield surface in order to cover a wide spectrum of reservoir rocks. The physico‐chemical processes taking place at pore collapse under oil‐ and water‐saturated conditions are discussed. The experimental data collected from previous works quantify the hardening and softening effects observed with decreasing porosity and increasing water saturation. The results also indicate that the stress interval characterising the elastic to elasto‐plastic transition zone and the curvature of the end cap are dependent on porosity and quartz content. These observed trends suggest changes in the sequence of local failures acting in the rock matrix at the onset of compaction. Comparisons with previous studies suggest that the water weakening effect differs between outcrop and reservoir chalk likely due to a change in mineralogy. A yield function is proposed to build the yield surface and to capture the porosity‐dependent change in the shape of end cap and the water weakening effect. The outcomes provide key input data describing the mechanical behaviour and properties of chalk under laboratory conditions required for compaction simulation studies.

ACS Style

F. Amour; H. F. Christensen; M. R. Hajiabadi; H. M. Nick. Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea. Journal of Geophysical Research: Solid Earth 2021, 126, 1 .

AMA Style

F. Amour, H. F. Christensen, M. R. Hajiabadi, H. M. Nick. Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea. Journal of Geophysical Research: Solid Earth. 2021; 126 (3):1.

Chicago/Turabian Style

F. Amour; H. F. Christensen; M. R. Hajiabadi; H. M. Nick. 2021. "Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea." Journal of Geophysical Research: Solid Earth 126, no. 3: 1.

Journal article
Published: 17 March 2021 in Journal of Industrial and Engineering Chemistry
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The shift in the wetting conditions during injection of modified salinity water (MSW) in carbonate reservoirs has been interpreted in several recent works through the DLVO extended theory. Two simplifications are usually adopted when applying the DLVO extended theory: (i) the electrostatic energy interaction is quantified by an analytical solution developed for systems containing only monovalent ions and (ii) the structural forces are independent of the type of brine. We address those by prioritizing the brine chemistry. We initially calculate the potential at the mineral and oil surfaces using two different surface complexation models implemented in Phreeqc and then we quantify the electrostatic forces by solving numerically the Poisson Boltzmann (PB) equations for non/symmetrical electrolytes. We observe that not only the identity of the ions, but also, more importantly, the boundary conditions (constant surface charge or constant surface potential) considered for the solution of PB can drastically modify the calculated electrostatic energy profile. We then calculate the total interaction energy and estimate a microscopic contact angle that is consistent with measured values. Our calculations show that increasing the concentration of salts such as MgCl2, CaCl2, and MgSO4 leads to more water-wet conditions, whereas salts like NaCl, KCl, and Na2SO4 show the opposite effect.

ACS Style

MirHossein Taheriotaghsara; Maria Bonto; Hamid M. Nick; Ali Akbar Eftekhari. Estimation of calcite wettability using surface forces. Journal of Industrial and Engineering Chemistry 2021, 98, 444 -457.

AMA Style

MirHossein Taheriotaghsara, Maria Bonto, Hamid M. Nick, Ali Akbar Eftekhari. Estimation of calcite wettability using surface forces. Journal of Industrial and Engineering Chemistry. 2021; 98 ():444-457.

Chicago/Turabian Style

MirHossein Taheriotaghsara; Maria Bonto; Hamid M. Nick; Ali Akbar Eftekhari. 2021. "Estimation of calcite wettability using surface forces." Journal of Industrial and Engineering Chemistry 98, no. : 444-457.

Journal article
Published: 20 January 2021 in Geothermics
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Direct Use Geothermal Systems (DUGS) are increasing their installed capacity worldwide and denser developments with multiple doublets are becoming more common. Interference between doublets therefore becomes an additional concern to subsurface uncertainties. Faults can be either barriers or conduits to flow and can affect the fluid pathways inside the reservoir. The interference between two doublets that are separated by a fault has not been previously studied for DUGS. In this work considering subsurface uncertainty in a full factorial design using 5184 3D reservoir simulations we show that a fault can reduce the system lifetime of a two-doublet system by more than 40 % if one doublet is at close proximity to it. Further, we identify that the fault can also improve both the system lifetime and generated Net Present Value (NPV) with appropriate development decisions. Contrary to previous results that did not consider reservoir architecture, a tramline well configuration is preferable when the doublets have the fault in the centre, while a checkerboard configuration is preferable as the distance to the fault decreases. The Heat In Place (HIP) recovery shows a linear relationship with flow rate and well spacing that is not affected by the fault distance or flow properties. The dimensions of the Influence Area (IA) previously considered are insufficient to capture the temperature drop at the producer wells and the fault position can increase this discrepancy. Our results show the importance of fault characterisation and well positioning with respect to a fault considering subsurface uncertainty and how this can affect denser field development of DUGS. Our findings suggest to integrate faults and the relative positioning of well doublets with respect to a fault more strongly in field development plans. Such considerations should also be included in future optimization plans of multi-well geothermal systems. Moreover, the regulatory framework should be revised to achieve a better match between the IA boundary and the production well temperature drop to enable better planning for denser development of DUGS.

ACS Style

Alexandros Daniilidis; Hamidreza M. Nick; David F. Bruhn. Interference between geothermal doublets across a fault under subsurface uncertainty; implications for field development and regulation. Geothermics 2021, 91, 102041 .

AMA Style

Alexandros Daniilidis, Hamidreza M. Nick, David F. Bruhn. Interference between geothermal doublets across a fault under subsurface uncertainty; implications for field development and regulation. Geothermics. 2021; 91 ():102041.

Chicago/Turabian Style

Alexandros Daniilidis; Hamidreza M. Nick; David F. Bruhn. 2021. "Interference between geothermal doublets across a fault under subsurface uncertainty; implications for field development and regulation." Geothermics 91, no. : 102041.

Journal article
Published: 06 December 2020 in International Biodeterioration & Biodegradation
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Microbial sulfate reduction is the most significant source of hydrogen sulfide (souring) as oil reservoirs are flooded with seawater (with mM concentrations of sulfate) for secondary oil recovery. Nitrate (nitrite) injections into the reservoirs are routinely used to constrain souring. Perchlorate was proposed as an alternative souring mitigation agent, however its effectiveness remains to be determined on a field scale. We used a combination of laboratory-based experiments and field scale numerical models to compare the efficacy of nitrate, nitrite, and perchlorate in inhibiting sulfide production in offshore oil reservoirs. Our results suggest that on a field scale perchlorate inhibits sulfide accumulation by inhibiting sulfate reduction and promoting sulfide oxidation. Elemental sulfur production was observed during nitrate reduction by Archaeglobus fulgidus confirming previous suggestions that the process is coupled to the oxidation of sulfide. Finally, nitrite was the most efficient inhibitor of sulfide accumulation, further confirmed by our field scale simulations. Our field scale simulations predict that injection of 1 mM of nitrite can reduce souring by 92%, while perchlorate (1 mM) or nitrate (1 mM) have the potential to reduce sulfide accumulation by 57% and 80% respectively.

ACS Style

Moein J. Veshareh; Kasper U. Kjeldsen; Alyssa J. Findlay; Hamidreza M. Nick; Hans Røy; Angeliki Marietou. Nitrite is a more efficient inhibitor of microbial sulfate reduction in oil reservoirs compared to nitrate and perchlorate: A laboratory and field-scale simulation study. International Biodeterioration & Biodegradation 2020, 157, 105154 .

AMA Style

Moein J. Veshareh, Kasper U. Kjeldsen, Alyssa J. Findlay, Hamidreza M. Nick, Hans Røy, Angeliki Marietou. Nitrite is a more efficient inhibitor of microbial sulfate reduction in oil reservoirs compared to nitrate and perchlorate: A laboratory and field-scale simulation study. International Biodeterioration & Biodegradation. 2020; 157 ():105154.

Chicago/Turabian Style

Moein J. Veshareh; Kasper U. Kjeldsen; Alyssa J. Findlay; Hamidreza M. Nick; Hans Røy; Angeliki Marietou. 2020. "Nitrite is a more efficient inhibitor of microbial sulfate reduction in oil reservoirs compared to nitrate and perchlorate: A laboratory and field-scale simulation study." International Biodeterioration & Biodegradation 157, no. : 105154.

Journal article
Published: 25 November 2020 in Journal of Computational Physics
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In this paper, we utilize the enriched Galerkin (EG) finite element method for the flow equation in Biot's system, which provides a robust locally conservative flux in heterogeneous porous media. The computational algorithm to solve the coupled system with the permeability alteration is presented with the linearization and Picard's iterative scheme. The block structure is utilized for the linear system in numerical discretization, and the computer code is shared in the open-source platform. In the numerical experiments, we compare the proposed EG method with the classical continuous Galerkin (CG) and discontinuous Galerkin (DG) finite element methods in different scenarios, including the North sea reservoirs setup. While DG and EG methods provide similar approximations for the pressure solutions, the CG method produces spurious oscillations in fluid pressure and volumetric strain solutions near the material interfaces, especially for the soft materials. The difference of flux approximation between EG and DG methods is insignificant; still, the EG method demands approximately two and three times fewer degrees of freedom than the DG method for two- and three-dimensional geometries.

ACS Style

T. Kadeethum; H.M. Nick; S. Lee; F. Ballarin. Enriched Galerkin discretization for modeling poroelasticity and permeability alteration in heterogeneous porous media. Journal of Computational Physics 2020, 427, 110030 .

AMA Style

T. Kadeethum, H.M. Nick, S. Lee, F. Ballarin. Enriched Galerkin discretization for modeling poroelasticity and permeability alteration in heterogeneous porous media. Journal of Computational Physics. 2020; 427 ():110030.

Chicago/Turabian Style

T. Kadeethum; H.M. Nick; S. Lee; F. Ballarin. 2020. "Enriched Galerkin discretization for modeling poroelasticity and permeability alteration in heterogeneous porous media." Journal of Computational Physics 427, no. : 110030.

Journal article
Published: 16 November 2020 in International Journal of Rock Mechanics and Mining Sciences
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Open hole wellbores present cost efficient completion solution; however, instability of such boreholes in weak formations such as chalk in the course of production raises a concern. This paper presents a method for predicting the stability of the radial jet drilling laterals in the Danish Gorm chalk field. The method is based on four main parts: (1) rock mechanics testing in the triaxial cell; (2) the single lateral hole testing consisting of loading and fluid flow test; (3) utilizing CT imaging for identifying the damaged zone and its extension; and (4) numerical simulations, utilizing a chalk model that takes into account the post-peak softening and the rate dependency of the pore collapse stress. Simulation of bottom hole and reservoir pressure decline over a year by 17 MPa and 9 MPa, respectively, showed a small development of the plastic strain at the borehole wall. Further simulation up to four years with constant stress (creep) resulted in a change in the cross-sectional area of the borehole, where shear cracks developed at the wall and some distance away from the hole stress concentrations associated with pore collapse was observed. By the end of the simulation, the borehole was likely to change its geometry by removal of the plastified area. The single lateral hole test with flow carried out with differential pore pressure, drawdown, of about 2.5 MPa within 5 h and 1 h, respectively, provided insignificant permeability change during the flow test.

ACS Style

M.K. Medetbekova; M.R. Hajiabadi; H.F. Christensen; A. Brovelli; A. Shamsolhodaei; H.O. Sørensen; D. Müter; H.M. Nick. Evaluation of the behaviour of the lateral boreholes in the Gorm chalk field. International Journal of Rock Mechanics and Mining Sciences 2020, 136, 104499 .

AMA Style

M.K. Medetbekova, M.R. Hajiabadi, H.F. Christensen, A. Brovelli, A. Shamsolhodaei, H.O. Sørensen, D. Müter, H.M. Nick. Evaluation of the behaviour of the lateral boreholes in the Gorm chalk field. International Journal of Rock Mechanics and Mining Sciences. 2020; 136 ():104499.

Chicago/Turabian Style

M.K. Medetbekova; M.R. Hajiabadi; H.F. Christensen; A. Brovelli; A. Shamsolhodaei; H.O. Sørensen; D. Müter; H.M. Nick. 2020. "Evaluation of the behaviour of the lateral boreholes in the Gorm chalk field." International Journal of Rock Mechanics and Mining Sciences 136, no. : 104499.

Journal article
Published: 10 November 2020 in Advances in Water Resources
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Fine-scale discrete fracture simulations provide a natural means to quantify the matrix-fracture fluxes and to provide reference solutions for upscaling approaches such as dual porosity/dual permeability models. Since typically the fine-scale simulations are computationally demanding, and the fractured reservoirs are highly heterogeneous, it is desirable to parametrize the fracture geometry and to obtain coarse-scale model closures using precomputed fine-scale results. We show that this can be done for the case of two-dimensional geometries and compressible single-phase flows. Specifically, a set of parameters linked to a coarse-scale grid block can be mapped to the underlying fracture geometry via a convolutional neural network. In particular, if a matrix-fracture transfer function can be parametrized with a number of parameters spatially varying on a coarse scale, the shape of the transfer function per grid block can be learned from fine-scale simulations.

ACS Style

Nikolai Andrianov; Hamidreza M. Nick. Machine learning of dual porosity model closures from discrete fracture simulations. Advances in Water Resources 2020, 147, 103810 .

AMA Style

Nikolai Andrianov, Hamidreza M. Nick. Machine learning of dual porosity model closures from discrete fracture simulations. Advances in Water Resources. 2020; 147 ():103810.

Chicago/Turabian Style

Nikolai Andrianov; Hamidreza M. Nick. 2020. "Machine learning of dual porosity model closures from discrete fracture simulations." Advances in Water Resources 147, no. : 103810.

Research article
Published: 10 November 2020 in ACS Omega
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Modified salinity water (MSW) core flooding tests conducted in carbonates often exhibit a delay in the additional oil recovery. It has been suggested that the ionic adsorption process controls this delay. In this study, we examine the adverse effect of the adsorption process on the performance of MSW flooding in various models categorized as layered and heterogeneous reservoirs and a North Sea field sector model. To evaluate the impact of porous media’s heterogeneity on the delay caused by the adsorption, we introduce the net present volumetric value based on which the cost of delay is calculated. This evaluation is achieved by comparing the calculated cost of delay for heterogeneous systems and that of their equivalent homogeneous porous media. It is found that, as the level of reservoir heterogeneity increases, the adverse effect of ionic adsorption on the improved oil production decreases. Further, computational results suggest that the connectivity index, which is defined as the effective permeability between injection and production wells divided by the average permeability, is a better alternative to the vorticity index to describe the impact of the delay of additional oil recovery in heterogeneous reservoirs subjected to MSW flooding.

ACS Style

MirHossein Taheriotaghsara; Seyedbehzad Hosseinzadehsadati; Hamidreza M. Nick. The Impact of Spatially Correlated Heterogeneity and Adsorption on Modified Salinity Water in Carbonates. ACS Omega 2020, 5, 29780 -29794.

AMA Style

MirHossein Taheriotaghsara, Seyedbehzad Hosseinzadehsadati, Hamidreza M. Nick. The Impact of Spatially Correlated Heterogeneity and Adsorption on Modified Salinity Water in Carbonates. ACS Omega. 2020; 5 (46):29780-29794.

Chicago/Turabian Style

MirHossein Taheriotaghsara; Seyedbehzad Hosseinzadehsadati; Hamidreza M. Nick. 2020. "The Impact of Spatially Correlated Heterogeneity and Adsorption on Modified Salinity Water in Carbonates." ACS Omega 5, no. 46: 29780-29794.

Journal article
Published: 03 November 2020 in Energy & Fuels
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ACS Style

MirHossein Taheriotaghsara; Ali A. Eftekhari; Hamidreza M. Nick. Adsorption- and Diffusion-Controlled Wettability Change in Modified Salinity Water Flooding. Energy & Fuels 2020, 34, 13767 -13781.

AMA Style

MirHossein Taheriotaghsara, Ali A. Eftekhari, Hamidreza M. Nick. Adsorption- and Diffusion-Controlled Wettability Change in Modified Salinity Water Flooding. Energy & Fuels. 2020; 34 (11):13767-13781.

Chicago/Turabian Style

MirHossein Taheriotaghsara; Ali A. Eftekhari; Hamidreza M. Nick. 2020. "Adsorption- and Diffusion-Controlled Wettability Change in Modified Salinity Water Flooding." Energy & Fuels 34, no. 11: 13767-13781.

Special issue
Published: 01 October 2020 in Mathematical Geosciences
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We study and compare five different combinations of finite element spaces for approximating the coupled flow and solid deformation system, so-called Biot’s equations. The permeability and porosity fields are heterogeneous and depend on solid displacement and fluid pressure. We provide detailed comparisons among the continuous Galerkin, discontinuous Galerkin, enriched Galerkin, and two types of mixed finite element methods. Several advantages and disadvantages for each of the above techniques are investigated by comparing local mass conservation properties, the accuracy of the flux approximation, number of degrees of freedom (DOF), and wall and CPU times. Three-field formulation methods with fluid velocity as an additional primary variable generally require a larger number of DOF, longer wall and CPU times, and a greater number of iterations in the linear solver in order to converge. The two-field formulation, a combination of continuous and enriched Galerkin function space, requires the fewest DOF among the methods that conserve local mass. Moreover, our results illustrate that three out of the five methods conserve local mass and produce similar flux approximations when conductivity alteration is included. These comparisons of the key performance indicators of different combinations of finite element methods can be utilized to choose the preferred method based on the required accuracy and the available computational resources.

ACS Style

T. Kadeethum; S. Lee; H. M. Nick. Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media. Mathematical Geosciences 2020, 52, 977 -1015.

AMA Style

T. Kadeethum, S. Lee, H. M. Nick. Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media. Mathematical Geosciences. 2020; 52 (8):977-1015.

Chicago/Turabian Style

T. Kadeethum; S. Lee; H. M. Nick. 2020. "Finite Element Solvers for Biot’s Poroelasticity Equations in Porous Media." Mathematical Geosciences 52, no. 8: 977-1015.

Erratum
Published: 26 June 2020 in Geothermics
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ACS Style

Alexandros Daniilidis; Hamidreza M. Nick; David F. Bruhn. Corrigendum to “Interdependencies between physical, design and operational parameters for direct use geothermal heat in faulted hydrothermal reservoirs” [Geothermics, 86 (2020) 101806]. Geothermics 2020, 87, 101900 .

AMA Style

Alexandros Daniilidis, Hamidreza M. Nick, David F. Bruhn. Corrigendum to “Interdependencies between physical, design and operational parameters for direct use geothermal heat in faulted hydrothermal reservoirs” [Geothermics, 86 (2020) 101806]. Geothermics. 2020; 87 ():101900.

Chicago/Turabian Style

Alexandros Daniilidis; Hamidreza M. Nick; David F. Bruhn. 2020. "Corrigendum to “Interdependencies between physical, design and operational parameters for direct use geothermal heat in faulted hydrothermal reservoirs” [Geothermics, 86 (2020) 101806]." Geothermics 87, no. : 101900.

Research article
Published: 10 June 2020 in Energy & Fuels
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The complex physicochemical interactions in the calcite-brine-crude oil system, triggered by the injection of modified salinity water (MSW) into the reservoir, are modeled by several researchers. However, the proposed models are either not consistent with a wettability alteration mechanism or cannot explain the observed improved oil recovery in chalk. We propose a new methodology denominated “Available Adsorption Sites” (AAS) that assesses the wettability alteration as a combined effect of a chemical and electrostatic contribution. Thus, we describe mathematically the interactions between the polar groups in the oil phase and the chalk by considering analogy with the thermodynamics of adsorption of an ion on a charged surface. The chalk wetting properties depend on the number of sites available for the adsorption of oleic polar groups at the mineral surface and the electrical potential at the rock-brine and brine-oil interfaces. We evaluate how the AAS parameter correlates with the remaining oil saturation from spontaneous imbibition tests on chalk samples. This approach is not only useful for the predictive evaluation of the outcome of MSW in chalk reservoirs but can also be integrated in reactive transport models and assess the flow of organic contaminants (e.g., naphtenic acids) in chalk aquifers. The model can potentially be applied to other carbonates.

ACS Style

María Bonto; Ali Akbar Eftekhari; Hamidreza M. Nick. Wettability Indicator Parameter Based on the Thermodynamic Modeling of Chalk-Oil-Brine Systems. Energy & Fuels 2020, 34, 1 .

AMA Style

María Bonto, Ali Akbar Eftekhari, Hamidreza M. Nick. Wettability Indicator Parameter Based on the Thermodynamic Modeling of Chalk-Oil-Brine Systems. Energy & Fuels. 2020; 34 (7):1.

Chicago/Turabian Style

María Bonto; Ali Akbar Eftekhari; Hamidreza M. Nick. 2020. "Wettability Indicator Parameter Based on the Thermodynamic Modeling of Chalk-Oil-Brine Systems." Energy & Fuels 34, no. 7: 1.

Journal article
Published: 01 June 2020 in International Journal of Geomechanics
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Increasing reservoir connectivity to the wellbore and bypassing the damaged area is crucial in improving the productivity of the wells and enhancing the swept area. This has become feasible by a new technology called radial jet drilling (RJD), in which relatively long, small-diameter laterals can be drilled radially from the main wellbore. In this study, the authors attempt to gain a better understanding of the efficiency of a high-velocity jet drilling on chalk destruction, and also identify parameters controlling the jet drilling. For this purpose, two distinct outcrop chalks from Austin, Texas (US) and Northern Province, Welton (UK) are used in this study, which are analogs to the reservoir chalk in the North Sea. In conjunction with the jet drilling experiments, basic rock mechanics testing is carried out in order to correlate the rock strength and stiffness properties to the jet drilling performance. Jet drilling of boreholes is evaluated not only by varying the fluid and nozzle type and the fluid pressure at the nozzle, but also varying the jet drilling setup under unconfined and also confined stress fields resembling reservoir condition. Results of our study show a clear correlation of the rock strength (and stiffness) on the threshold pressure and specific energy required to break the rock. Tight chalk requires more than 30% higher pump pressure than used in soft chalk for breaking the chalk, having more than twice the strength properties. Soft chalk presents larger borehole size and better rate of penetration, both with water and acid-aided fluid, owing to its higher matrix permeability value, as well as lower mechanical properties that favor diffusion of the jet drilling fluid into the rock and faster erosion/breakage compared with tight chalk. Static nozzles create a larger surface area compared with rotating nozzles. The penetration rate of the nozzle is improved significantly under stress confinement. In addition, jet drilling in the direction of minimum principal stress (σ3) appears to be faster owing to localization of shear failure around the drilled hole induced by the differential stresses compared with the jet drilling in the direction of maximum principal stress (σ1) under isotropic stress or ambient conditions.

ACS Style

M. K. Medetbekova; H. F. Christensen; S. Salimzadeh; R. R. Bakker; H. M. Nick. Experimental Investigation of Drilling Lateral Boreholes in Chalk Rocks with High-Pressure Jets. International Journal of Geomechanics 2020, 20, 04020049 .

AMA Style

M. K. Medetbekova, H. F. Christensen, S. Salimzadeh, R. R. Bakker, H. M. Nick. Experimental Investigation of Drilling Lateral Boreholes in Chalk Rocks with High-Pressure Jets. International Journal of Geomechanics. 2020; 20 (6):04020049.

Chicago/Turabian Style

M. K. Medetbekova; H. F. Christensen; S. Salimzadeh; R. R. Bakker; H. M. Nick. 2020. "Experimental Investigation of Drilling Lateral Boreholes in Chalk Rocks with High-Pressure Jets." International Journal of Geomechanics 20, no. 6: 04020049.

Journal article
Published: 31 May 2020 in Advances in Water Resources
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This paper presents the enriched Galerkin discretization for modeling fluid flow in fractured porous media using the mixed-dimensional approach. The proposed method has been tested against published benchmarks. Since fracture and porous media discontinuities can significantly influence single- and multi-phase fluid flow, the heterogeneous and anisotropic matrix permeability setting is utilized to assess the enriched Galerkin performance in handling the discontinuity within the matrix domain and between the matrix and fracture domains. Our results illustrate that the enriched Galerkin method has the same advantages as the discontinuous Galerkin method; for example, it conserves local and global fluid mass, captures the pressure discontinuity, and provides the optimal error convergence rate. However, the enriched Galerkin method requires much fewer degrees of freedom than the discontinuous Galerkin method in its classical form. The pressure solutions produced by both methods are similar regardless of the conductive or non-conductive fractures or heterogeneity in matrix permeability. This analysis shows that the enriched Galerkin scheme reduces the computational costs while offering the same accuracy as the discontinuous Galerkin so that it can be applied for large-scale flow problems. Furthermore, the results of a time-dependent problem for a three-dimensional geometry reveal the value of correctly capturing the discontinuities as barriers or highly-conductive fractures.

ACS Style

T. Kadeethum; H.M. Nick; S. Lee; F. Ballarin. Flow in porous media with low dimensional fractures by employing enriched Galerkin method. Advances in Water Resources 2020, 142, 103620 .

AMA Style

T. Kadeethum, H.M. Nick, S. Lee, F. Ballarin. Flow in porous media with low dimensional fractures by employing enriched Galerkin method. Advances in Water Resources. 2020; 142 ():103620.

Chicago/Turabian Style

T. Kadeethum; H.M. Nick; S. Lee; F. Ballarin. 2020. "Flow in porous media with low dimensional fractures by employing enriched Galerkin method." Advances in Water Resources 142, no. : 103620.

Research article
Published: 06 May 2020 in PLoS ONE
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This paper presents the potential of applying physics-informed neural networks for solving nonlinear multiphysics problems, which are essential to many fields such as biomedical engineering, earthquake prediction, and underground energy harvesting. Specifically, we investigate how to extend the methodology of physics-informed neural networks to solve both the forward and inverse problems in relation to the nonlinear diffusivity and Biot’s equations. We explore the accuracy of the physics-informed neural networks with different training example sizes and choices of hyperparameters. The impacts of the stochastic variations between various training realizations are also investigated. In the inverse case, we also study the effects of noisy measurements. Furthermore, we address the challenge of selecting the hyperparameters of the inverse model and illustrate how this challenge is linked to the hyperparameters selection performed for the forward one.

ACS Style

Teeratorn Kadeethum; Thomas M. Jørgensen; Hamidreza M. Nick. Physics-informed neural networks for solving nonlinear diffusivity and Biot’s equations. PLoS ONE 2020, 15, e0232683 .

AMA Style

Teeratorn Kadeethum, Thomas M. Jørgensen, Hamidreza M. Nick. Physics-informed neural networks for solving nonlinear diffusivity and Biot’s equations. PLoS ONE. 2020; 15 (5):e0232683.

Chicago/Turabian Style

Teeratorn Kadeethum; Thomas M. Jørgensen; Hamidreza M. Nick. 2020. "Physics-informed neural networks for solving nonlinear diffusivity and Biot’s equations." PLoS ONE 15, no. 5: e0232683.

Journal article
Published: 24 April 2020 in Fuel
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Research carried out in the context of the modified salinity water flooding in carbonates showed that tuning the ionic composition of the injection water in core flooding experiments can lead to a more water-wet system, eventually affecting the flow of the oleic and aqueous phases. Previous endeavors for mathematically modelling this problem include complex reactive transport models and an indicator for the mobility alteration of phases. Thanks to a large number of fitting parameters, almost all proposed models can reasonably fit a limited set of core-flooding recovery data, which makes the choice of physical mechanisms for the development of a mechanistic model irrelevant. Here, we address this problem by correlating the geochemical interactions of potential determining ions with a two-phase transport model and performing a constrained history matching of the modified salinity water flooding tests in secondary and tertiary mode. Instead of matching only the recovery factor and pressure drop history, we give a higher priority to matching the different ion concentrations and oil breakthrough times. Our results show that the oil breakthrough times can only be correctly obtained by accurately modeling the carbonate-brine physicochemical interactions and choosing the adsorbed potential determining ions’ concentrations as a mobility-modifier indicator. The important observation is that for most core-flooding experiments, the lag between the start of the injection of the modified-salinity brine and the oil breakthrough time can be better predicted by considering the wettability alteration due to the adsorption of potential determining ions on the carbonate surface.

ACS Style

MirHossein Taheriotaghsara; Maria Bonto; Ali Akbar Eftekhari; Hamidreza M. Nick. Prediction of oil breakthrough time in modified salinity water flooding in carbonate cores. Fuel 2020, 274, 117806 .

AMA Style

MirHossein Taheriotaghsara, Maria Bonto, Ali Akbar Eftekhari, Hamidreza M. Nick. Prediction of oil breakthrough time in modified salinity water flooding in carbonate cores. Fuel. 2020; 274 ():117806.

Chicago/Turabian Style

MirHossein Taheriotaghsara; Maria Bonto; Ali Akbar Eftekhari; Hamidreza M. Nick. 2020. "Prediction of oil breakthrough time in modified salinity water flooding in carbonate cores." Fuel 274, no. : 117806.