@article{LiSpangenbergSchicksetal.2022,
  author    = {Li, Zhen and Spangenberg, Erik and Schicks, Judith Maria and Kempka, Thomas},
  title     = {Numerical simulation of hydrate formation in the LArge-Scale Reservoir Simulator (LARS)},
  series = {Energies : open-access journal of related scientific research, technology development and studies in policy and management},
  volume    = {15},
  journal   = {Energies : open-access journal of related scientific research, technology development and studies in policy and management},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1073},
  doi       = {10.3390/en15061974},
  pages     = {27},
  year      = {2022},
  abstract  = {The LArge-scale Reservoir Simulator (LARS) has been previously developed to study hydrate dissociation in hydrate-bearing systems under in-situ conditions. In the present study, a numerical framework of equations of state describing hydrate formation at equilibrium conditions has been elaborated and integrated with a numerical flow and transport simulator to investigate a multi-stage hydrate formation experiment undertaken in LARS. A verification of the implemented modeling framework has been carried out by benchmarking it against another established numerical code. Three-dimensional (3D) model calibration has been performed based on laboratory data available from temperature sensors, fluid sampling, and electrical resistivity tomography. The simulation results demonstrate that temperature profiles, spatial hydrate distribution, and bulk hydrate saturation are consistent with the observations. Furthermore, our numerical framework can be applied to calibrate geophysical measurements, optimize post-processing workflows for monitoring data, improve the design of hydrate formation experiments, and investigate the temporal evolution of sub-permafrost methane hydrate reservoirs.},
  language  = {en}
}
@misc{vanderKroefKoszinskiGrinatetal.2020,
  author    = {van der Kroef, Ilona and Koszinski, Sylvia and Grinat, Michael and van der Meij, Marijn W. and Hierold, Wilfried and S{\"u}dekum, Wolfgang and Sommer, Michael},
  title     = {Digital mapping of buried soil horizons using 2D and pseudo-3D geoelectrical measurements in a ground moraine landscape},
  series = {European journal of soil science : EJSS},
  volume    = {71},
  journal   = {European journal of soil science : EJSS},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1351-0754},
  pages     = {10 -- 26},
  year      = {2020},
  abstract  = {The identification of buried soil horizons in agricultural landscapes helps to quantify sediment budgets and erosion-related carbon dynamics. High-resolution mapping of buried horizons using conventional soil surveys is destructive and time consuming. Geoelectrical sensors can offer a fast and non-destructive alternative for determining horizon positions and properties. In this paper, we compare the suitability of several geoelectrical methods for measuring the depth to buried horizons (Apb, Ahb and Hab) in the hummocky ground moraine landscape of northeastern Germany. Soil profile descriptions were developed for 269 locations within a 6-ha experimental field "CarboZALF-D". A stepwise linear discriminant analysis (LDA) estimated the lateral position of the buried horizons using electromagnetic induction data and terrain attributes. To predict the depth of a buried horizon, multiple linear regression (MLR) was used for both a 120-m transect and a 0.2-ha pseudo-three-dimensional (3D) area. At these scales, apparent electrical conductivity (ECa), electrical resistivity (ER) and terrain attributes were used as independent variables. The LDA accurately predicted Apb- and Ahb-horizons (a correct classification of 93\%). The LDA of the Hab-horizon had a misclassification of 24\%, which was probably related to the smaller test set and the higher depth of this horizon. The MLR predicted the depth of the Apb-, Ahb- and Hab-horizons with relative root mean square errors (RMSEs) of 7, 3 and 13\%, respectively, in the pseudo-3D area. MLR had a lower accuracy for the 2D transect compared to the pseudo-3D area. Overall, the use of LDA and MLR has been an efficient methodological approach for predicting buried horizon positions. Highlights The suitability of geoelectrical measurements for digital modelling of diagnostic buried soil horizons was determined. LDA and MLR were used to detect multiple horizons with geoelectrical devices and terrain attributes. Geoelectrical variables were significant predictors of the position of the target soil horizons. The use of these tested digital technologies gives an opportunity to develop high-resolution soil mapping procedures.},
  language  = {en}
}