scholarly journals A Numerical Simulator for Modeling the Coupling Processes of Subsurface Fluid Flow and Reactive Transport Processes in Fractured Carbonate Rocks

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1957 ◽  
Author(s):  
Yuan ◽  
Wei ◽  
Zhang ◽  
Qin
Keyword(s):  
Fluid Flow ◽  
Chemical Reactions ◽  
Reactive Transport ◽  
Radial Flow ◽  
Transport Processes ◽  
Coupled Processes ◽  
Rock Properties ◽  
Brinkman Equation ◽  
Fractured Carbonate ◽  
Carbonate Formations

Water–rock interactions can alter rock properties through chemical reactions during subsurface transport processes like geological CO2 sequestration (GCS), matrix acidizing, and waterflooding in carbonate formations. Dynamic changes in rock properties cause a failure of waterflooding and GCS and could also dramatically affect the efficiency of the acidizing. Efficient numerical simulations are thus essential to the optimized design of those subsurface processes. In this paper, we develop a three-dimensional (3D) numerical model for simulating the coupled processes of fluid flow and chemical reactions in fractured carbonate formations. In the proposed model, we employ the Stokes–Brinkman equation for momentum balance, which is a single-domain formulation for modeling fluid flow in fractured porous media. We then couple the Stokes–Brinkman equation with reactive-transport equations. The model can be formulated to describe linear as well as radial flow. We employ a decoupling procedure that sequentially solves the Stokes–Brinkman equation and the reactive transport equations. Numerical experiments show that the proposed method can model the coupled processes of fluid flow, solute transport, chemical reactions, and alterations of rock properties in both linear and radial flow scenarios. The rock heterogeneity and the mineral volume fractions are two important factors that significantly affect the structure of conductive channels.

On the constitutive equations for coupled chemical reaction and deformation of porous rocks

2021 ◽  
Author(s):  
Yury Podladchikov ◽  
Viktoriya Yarushina ◽  
Benjamin Malvoisin
Keyword(s):  
Fluid Flow ◽  
Chemical Reactions ◽  
Constitutive Equations ◽  
Reactive Transport ◽  
Coupled Processes ◽  
Stable Phase ◽  
Precipitation Process ◽  
Porous Rocks ◽  
Mineral Growth ◽  
Reactive Surfaces

<p>Deformation, chemical reactions, and fluid flow in the geological materials are coupled processes. While some reactions are thought to be a consequence of fluid assisted dissolution on the stressed mineral surfaces and precipitation on the free surface, other reactions are caused by mineral replacement wherein a less stable mineral phase is replaced by a more stable phase, involving a change in solid volume and build-up of stresses on grain contacts, also known as a force of crystallization. Most of the existing models of chemical reactions coupled with fluid transport either assume dissolution-precipitation process or mineral growth in rocks. However, dissolution-precipitation models used together with fluid flow modelling predict a very limited extent of reaction hampered by pore clogging and blocking of reactive surfaces, which will stop reaction progress due to the limited supply of fluid to reactive surfaces. Yet, field observations report that natural rocks can undergo 100% hydration/carbonation. Mineral growth models, on the other hand, preserve solid volume but do not consider its feedback on porosity evolution. In addition, they predict the unrealistically high force of crystallization on the order of several GPa that must be developed in minerals during the reaction. Here, using a combination of effective media theory and irreversible thermodynamics approaches, we propose a new model for reaction-driven mineral expansion, which preserves porosity and limits unrealistically high build-up of the force of crystallization by allowing inelastic failure processes at the pore scale. To fully account for the coupling between reaction, deformation, and fluid flow we derive macroscopic poroviscoelastic stress-strain constitute laws, that account for chemical alteration and viscoleastic deformation of porous rocks. These constitutive equations are then used to simulate the reactive transport in porous rocks.</p>

scholarly journals A parallelization scheme to simulate reactive transport in the subsurface environment with OGS#IPhreeqc

2015 ◽  
Vol 8 (3) ◽  
pp. 2369-2402
Author(s):  
W. He ◽  
C. Beyer ◽  
J. H. Fleckenstein ◽  
E. Jang ◽  
O. Kolditz ◽  
...  
Keyword(s):  
Message Passing ◽  
Reactive Transport ◽  
Message Passing Interface ◽  
Transport Processes ◽  
Coupled Processes ◽  
Scientific Software ◽  
Geochemical Reactions ◽  
Optimized Allocation ◽  
And Performance ◽  
The One

Abstract. This technical paper presents an efficient and performance-oriented method to model reactive mass transport processes in environmental and geotechnical subsurface systems. The open source scientific software packages OpenGeoSys and IPhreeqc have been coupled, to combine their individual strengths and features to simulate thermo-hydro-mechanical-chemical coupled processes in porous and fractured media with simultaneous consideration of aqueous geochemical reactions. Furthermore, a flexible parallelization scheme using MPI (Message Passing Interface) grouping techniques has been implemented, which allows an optimized allocation of computer resources for the node-wise calculation of chemical reactions on the one hand, and the underlying processes such as for groundwater flow or solute transport on the other hand. The coupling interface and parallelization scheme have been tested and verified in terms of precision and performance.

scholarly journals Numerical Modeling of Reactive Transport and Self-Sealing Processes in the Fault-Controlled Geothermal System of the Guide Basin, China

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Zhaoyun Hou ◽  
Tianfu Xu ◽  
Guanhong Feng ◽  
Bo Feng ◽  
Yilong Yuan ◽  
...  
Keyword(s):  
Reactive Transport ◽  
Major Ions ◽  
Damage Zone ◽  
Transport Processes ◽  
Coupled Processes ◽  
Discharge Zone ◽  
Geothermal System ◽  
High Concentration ◽  
Calcite Veins ◽  
Guide Basin

Strong chemical reactions in the geothermal systems may cause sealing of fractures, which reduces the permeability in the reservoir and subsequently affects the heat production. However, it is difficult to reveal the sealing range in a deeply buried reservoir based on a limited number of downhole logs. This study recreated the sealing processes of the fault-controlled geothermal system in the Guide Basin, China, by reactive transport modeling. The modeling domain was discretized based on multiple interacting continua (MINC) approach, to address the nonequilibrium heat transport processes between the matrix and conduit in the fractured fault damage zone. Once the model was validated by observations of major ions in spring water and downhole temperature logs in the discharge area, it was used to determine the coupled processes of fluid, heat, and chemical transport in the reservoir and the resultant sealing ranges. It was found that the dissolution of albite and K-feldspar leads to the precipitation of smectite-Ca and illite in the middle and bottom of the fault under the condition of high concentration of Ca2+ and Mg2+ in the recharge water. Calcite veins were formed in discharge zone, because the horizontal fast flow in shallow subsurface zone supplied abundant Ca2+ and HCO3-. As a consequence, the permeability in the discharge zone reduced by 15% when compared to the original permeability of 100 mD. Moreover, another three self-sealing areas were formed near the recharge zone, the deep upgradient zone, and the downgradient area where the fast upward fluid flow occurred. Self-sealing subsequently prevented the deep circulation of the flow and heat absorption, which tends to make the fault-controlled geothermal system inactive.

scholarly journals A parallelization scheme to simulate reactive transport in the subsurface environment with OGS#IPhreeqc 5.5.7-3.1.2

2015 ◽  
Vol 8 (10) ◽  
pp. 3333-3348 ◽  
Author(s):  
W. He ◽  
C. Beyer ◽  
J. H. Fleckenstein ◽  
E. Jang ◽  
O. Kolditz ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Message Passing ◽  
Reactive Transport ◽  
High Performance ◽  
Message Passing Interface ◽  
Coupled Processes ◽  
Scientific Software ◽  
Wide Range ◽  
Optimized Allocation ◽  
Set Up

Abstract. The open-source scientific software packages OpenGeoSys and IPhreeqc have been coupled to set up and simulate thermo-hydro-mechanical-chemical coupled processes with simultaneous consideration of aqueous geochemical reactions faster and easier on high-performance computers. In combination with the elaborated and extendable chemical database of IPhreeqc, it will be possible to set up a wide range of multiphysics problems with numerous chemical reactions that are known to influence water quality in porous and fractured media. A flexible parallelization scheme using MPI (Message Passing Interface) grouping techniques has been implemented, which allows an optimized allocation of computer resources for the node-wise calculation of chemical reactions on the one hand and the underlying processes such as for groundwater flow or solute transport on the other. This technical paper presents the implementation, verification, and parallelization scheme of the coupling interface, and discusses its performance and precision.

scholarly journals Modeling of Flow and Transport in Saturated and Unsaturated Porous Media

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1088
Author(s):  
Anis Younes ◽  
Marwan Fahs ◽  
Philippe Ackerer
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Reactive Transport ◽  
Transport Processes ◽  
Flow And Transport ◽  
Current Trends ◽  
Process Understanding ◽  
Wide Range ◽  
Hyporheic Zones ◽  
Relevant Topic

Modeling fluid flow and transport processes in porous media is a relevant topic for a wide range of applications. In water resources problems, this topic presents specific challenges related to the multiphysical processes, large time and space scales, heterogeneity and anisotropy of natural porous media, and complex mathematical models characterized by coupled nonlinear equations. This Special Issue aims at collecting papers presenting new developments in the field of flow and transport in porous media. The 25 published papers deal with different aspects of physical processes and applications such as unsaturated and saturated flow, flow in fractured porous media, landslide, reactive transport, seawater intrusion, and transport within hyporheic zones. Based on their objectives, we classified these papers into four categories: (i) improved numerical methods for flow and mass transport simulation, (ii) looking for reliable models and parameters, (iii) laboratory scale experiments and simulations, and (iv) modeling and simulations for improved process understanding. Current trends on modeling fluid flow and transport processes in porous media are discussed in the conclusion.

Recent developments in the HPx-codes for coupled reactive transport in porous media

2021 ◽  
Author(s):  
Diederik Jacques ◽  
Jirka Simunek ◽  
Bertrand Leterme ◽  
Hans Meeussen ◽  
Eric Laloy
Keyword(s):  
Porous Media ◽  
Solute Transport ◽  
Reactive Transport ◽  
Environmental Science ◽  
Transport Processes ◽  
Machine Learning Techniques ◽  
Coupled Processes ◽  
Large Set ◽  
Geochemical Model ◽  
Scripting Language

<p>Coupled reactive transport codes are indispensable tools for simulating the fate of solutes in porous media for both environmental and engineering applications. HP1 and HP2/3 are some of the most versatile tools for coupled processes of variably-saturated water flow, multicomponent solute transport, heat transfer, and equilibrium-kinetic chemical reaction networks (Jacques et al., 2018). To date, multiple extensions are included that significantly increase the flexibility of the HPx codes. In addition to the default PHREEQC geochemical solver, HPx provides alternatives for the geochemical step: the geochemical solver ORCHESTRA (Meeussen, 2003) or direct scripting. The ORCHESTRA solver is relatively small and efficient and comes with a large set of user definable adsorption models, including the NICA-Donnan model. The choice of the scripting language has been extended from the classical BASIC scripting language to the structured, prototype-based programming variant of BASIC and Python. The latter gives the possibility to include several libraries of Python immediately in the HPx based models. For example, machine learning techniques can replace computationally expensive geochemical calculations to speed up the calculations. The HPx code is also coupled to the MT3D-USGS code, the groundwater solute transport simulator for MODFLOW. Via the MODFLOW-HYDRUS1D integration, soil flow and transport processes can be integrated as an unsaturated zone component into MODFLOW and MT3D-USGS. The last change is the updated graphical user interface (GUI) for the geochemical model input and post-processing output, incorporated in the standard HYDRUS GUI. Besides, a stand-alone GUI version is available as an advanced interface for geochemical calculations with PHREEQC.</p> <p> </p> <p>Jacques, D., J. Simunek, D. Mallants and M. T. van Genuchten (2018).  JOURNAL OF HYDROLOGY AND HYDROMECHANICS <strong>66</strong>(2): 211-226.</p> <p>Meeussen, J. C. L. (2003). Environmental Science & Technology <strong>37</strong>(6): 1175-1182.</p>

Quantification of the Loss Conduit Aperture During Lost Circulation in Fractured Carbonates

2021 ◽  
Author(s):  
Alexey Ruzhnikov ◽  
Ashley Johnson
Keyword(s):  
Drilling Fluid ◽  
Rock Properties ◽  
Circulation Zone ◽  
Lost Circulation ◽  
New Information ◽  
Fractured Carbonate ◽  
The Difference ◽  
New Vision ◽  
Carbonate Formations ◽  
Fractured Carbonates

Abstract Fractured carbonate formations around the world are prone to lost circulation that not only affects the well construction process but creating a longtime effect on the wellbore integrity. Despite multiple attempts to cure them the success rate is usually low. This manuscript is aiming to provide a new vision on the reason of lost circulation across carbonates. To have better understanding of the complete losses across the fractured carbonates the series of studies were initiated. At first to understand the strength of the loss zone the fracture closing pressure was evaluated via study of the fluid level in the annulus and back-calculation of the drilling fluid density effect on it. Secondary, the rock properties across the loss circulation zones were studied by using the microresistivity images, dip data, and imaging of fluid-saturated porous media. At last, the trial tests with different treatment materials were performed to evaluate the effect of it on curing the losses. The results of the studies brought new information and explained some previous unknowns. The formation strength across lost circulation zone was measured and it was confirmed to remain constant despite other changes of the well conduction parameters. It was also confirmed that the carbonates are naturally highly fractured having over 900 fractures along the wellbore. The lost circulation zone was characterized, and it was confirmed that the losses were not related to the fractures but rather to the karst, dissolution and to mega-fractures. The size and dip of the fractures were identified, and it was proven the possibility to treat them with conventional materials. However, the size of identified mega-fractures and karst zones exceed the fractures by 100 times in true vertical depth, and in horizontal wells the difference is thousands times due to measured depth. This new information explains the previous unsuccessful attempts with the conventional lost circulation materials. Further based on the newly available information the mathematic description of the lost circulation zones was provided.

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