A5086378122- NMR spectroscopy and applications
- Hydrocarbon exploration and reservoir analysis
- Geophysical and Geoelectrical Methods
- Seismic Imaging and Inversion Techniques
- Geothermal Energy Systems and Applications
- Geophysical Methods and Applications
- CO2 Sequestration and Geologic Interactions
- Hydraulic Fracturing and Reservoir Analysis
- Seismic Waves and Analysis
- Non-Destructive Testing Techniques
- Groundwater flow and contamination studies
- Reservoir Engineering and Simulation Methods
- Concrete Corrosion and Durability
- Advanced Neuroimaging Techniques and Applications
- Methane Hydrates and Related Phenomena
- Soil and Unsaturated Flow
- Enhanced Oil Recovery Techniques
- Advanced MRI Techniques and Applications
- Advanced NMR Techniques and Applications
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Coal Properties and Utilization
- Concrete and Cement Materials Research
- Material Properties and Processing
- Smart Materials for Construction
RWTH Aachen University
2016-2025
Grantmakers for Effective Organizations
2025
Fraunhofer Research Institution for Energy Infrastructures and Geotechnologies IEG
2010-2019
Leipzig University
2001-2002
Abstract Most activities of humankind take place in the transition zone between four compartments terrestrial system: unconfined aquifer, including unsaturated zone; surface water; vegetation; and atmosphere. The mass, momentum, heat energy fluxes these drive their mutual state evolution. Improved understanding processes that is important for climate projections, weather prediction, flood forecasting, water soil resources management, agriculture, quality control. different transport...
Abstract Model predictive control (MPC) is a promising approach for optimizing the performance of borehole heat exchangers (BHEs) in ground-source pump systems. The central element MPC forward model that predicts thermal dynamics ground. In this work, we validate prediction accuracy four BHE modeling approaches against real-world measurement data across various operational events and timescales. We simulate fluid temperature leaving using fully discretized 3-D numerical model,...
Gas hydrates have the potential to significantly disturb global climate change and alter subsurface stability, particularly in context of production due their extensive presence widespread distribution marine deposits. The electrical conductivity hydrate-bearing sediments (HBS) serves as a crucial parameter for hydrate reservoir prospection. However, HBS is influenced not only by saturation but also within pore space. This study presents numerical approach quantifying relationship between...
Summary This study presents the results of an interlaboratory test designed to evaluate accuracy Spectral Induced Polarization (SIP) measurements using controlled electrical networks. The study, conducted in Germany since 2006, involved 12 research institutes, six different impedance measurement devices, and four types networks specifically phase shift errors SIP measurements. networks, with impedances ranging from 100 kΩ 150 kΩ, represent high-impedance samples characteristics, pose...
Abstract. Nuclear magnetic resonance (NMR) relaxometry measurements are commonly used to characterize the storage and transport properties of water-saturated rocks. Estimations these based on direct link initial NMR signal amplitude porosity (water content) relaxation time pore size. Herein, shapes usually assumed be spherical or cylindrical. However, response at partial water saturation for natural sediments rocks may differ strongly from responses calculated cylindrical pores, because do...
Longitudinal and transverse nuclear magnetic resonance (NMR) relaxation signatures in porous rock were simulated on the microscale to examine quantify how physical hydrologic parameters, such as rock‐surface properties pore sizes, affect longitudinal NMR signals of real, complex media. Parameters studied were: field strength, susceptibility, coupling, surface reactivity. Using finite element method (FEM), simulations spatial‐ time‐dependent magnetization evolution arbitrary geometries,...
Concrete resistivity is an important durability related material parameter. It correlates with various properties, e.g., the reinforcement corrosion rate, water saturation degree and porosity. The typically determined on a structure by using Wenner probe. Unfortunately results can strongly be influenced heterogeneities, bars or inhomogeneous moisture distributions. Neglecting these effects lead to significant misinterpretations. In order consider influences quantitatively applicability of...
Impedance Spectroscopy (IS) measurements allow to study a wide range of polarization mechanisms associated with different frequency ranges. Experimental devices usually cover limited ranges sufficient accuracy. We propose (a) combination four-electrode and two-electrode (b) data mutual verification procedure using the actual sample under test. Hereby, we from 1 mHz 10 MHz. The relies on precondition that any dispersive disturbance decayed at some point within an overlapping between Hz 45...
In this study, spectral induced polarization (SIP) spectra were generated numerically to better understand how actual rock microstructure and electrolyte properties in pores affect the pattern, i.e., characteristic relaxation time of as well strength a pore system. The dynamics charge carriers three‐dimensional systems simulated using frequency‐dependent formulation Nernst–Planck–Poisson (NPP) ion‐transport equations. Basically, pore‐system model alternating stacked cylinders two different...
Thermal response functions are commonly used to describe the heat exchange capability of ground exchangers. When convolved with thermal load, they allow for a quick and efficient prediction temperature evolution. Typically, obtained through physical models transfer process. However, can also be reconstructed directly from real experimental data, such as measurements fluid leaving boreholes. Here we reconstruct monitoring data 40 borehole Each is connected horizontal pipe one three...
Research Article| November 01, 2011 Application of Electro-Osmosis to Reduce the Adhesion Clay during Mechanical Tunnel Driving GIOVANNI SPAGNOLI; SPAGNOLI 2 Department Engineering Geology and Hydrogeology, Lochnerstr. 4-20, 52064 Aachen, RWTH Aachen University, Germany 1Present address: Fugro Consult GmbH, Ostendstraße 17, 64319 Pfungstadt, Germany. 2Corresponding author email: g.spagnoli@fugro.de. Search for other works by this on: GSW Google Scholar NORBERT KLITZSCH; KLITZSCH Applied...
Abstract Spectral induced polarization (SIP) laboratory measurements on water‐saturated rocks show a strong correlation between the electrical strength and inner surface area of rocks. We investigate influence roughness SIP response by simulating frequency‐dependent complex conductivity micro‐scale rock models. Starting with smooth grain models, we introduce using two different approaches: increasing in fractal‐like manner, creating random structures, resulting more natural‐looking surfaces....
The capacitive resistivity (CR) method is a time‐ and labor‐saving alternative to traditional direct current (DC) methods. line electrode variant of CR suffers from the absence data inversion programs as available for DC method. Direct were applied determine distribution measurements using an approximately equivalent four‐point dipole–dipole configuration. We optimized configurations minimize systematic error applying CR, based on comparison two‐dimensional sensitivities proposed...
Abstract Applying an integrated methodology, including petrography, mercury injection capillary pressure, laboratory nuclear magnetic resonance and X‐ray computed tomography, on continental spring carbonate reservoir analogue samples is a prerequisite to understand plug scale porosity permeability heterogeneities. Depending the dominant pore type in sample, orientation distribution of pores, network connectivity varies from poor excellent these carbonates. The latter exhibit large‐scale...
SHEMAT-Suite is a finite-difference open-source code for simulating coupled flow, heat and species transport in porous media. The code, written Fortran-95, originates from geoscientific research the fields of geothermics hydrogeology. It comprises: (1) versatile handling input output, (2) modular framework subsurface parameter modeling, (3) multi-level OpenMP parallelization, (4) estimation data assimilation by stochastic approaches (Monte Carlo, Ensemble Kalman filter) deterministic...
Abstract We study the feasibility of detecting carbon dioxide (CO 2 ) movement in overburden a storage reservoir due to CO leakage through an abandoned well by self‐potential (SP) measurements at surface. This is achieved with three‐dimensional numerical modeling two‐phase fluid flow and electrokinetic coupling between streaming potential. find that, typical scenarios, for leaky and/or injection wells conductive metal casing, signals originating from can be identified As signal also observed...
Measurement of nuclear magnetic resonance (NMR) relaxation is a well-established laboratory/borehole method to characterize the storage and transport properties rocks due its direct sensitivity corresponding pore-fluid content (water/oil) pore sizes. Using NMR, correct estimation of, e.g., permeability strongly depends on underlying model. Usually, one assumes spherical or cylindrical pores for interpreting NMR data. To obtain surface relaxivity thus, pore-size distribution, calibration...