Andrea Balza Morales

Andrea Balza Morales's profile picture
Andrea Balza Morales
PhD researcher
Postal address:
M.Sc. Andrea Balza Morales
Geophysical Imaging and Monitoring
RWTH Aachen University
Wüllnerstr. 2 (Bergbaugebäude)
Room: 505d
52062 Aachen

Research Interests

  • Gravity and magnetic data processing and inversion
  • Time-lapse monitoring techniques
  • Structure-based inversion
  • 3D Geological modeling
  • Geothermal exploration using joint interpretation and inversion


2021 – present PhD Researcher at RWTH Aachen and ETH Zürich within the MSCA Action EASYGO
2014 – 2017 Masters of Geophysics (M.Sc.) at Colorado School of Mines (Golden, Colorado)
2012 – 2013 International Exchange Program at University of New Mexico (Albuquerque, New Mexico)
2008 – 2013 Geophysical Engineering (B.Sc.) at Universidad Simon Bolivar (Caracas, Venezuela)

Professional experience

2013 – 2021 Geophysical Data Processor at EDCON-PRJ Inc (Denver, Colorado)
2016 – 2017 Graduate Research Assistant at Colorado School of Mines (Golden, Colorado)

Awards and service to profession

2012 – 2013 Mendenhall Prize for Outstanding Graduating Master of Science Students, Department of Geophysics, Colorado School of Mines. Denver, Colorado
2004 – 2005 All-American Scholar award, United States Achievement Academy. Miami, Florida
2020 – 2022 Serving Chair, Geophysical Society of Houston, Potential Field Special Interest Group
2021 Membership Committee, EEGS, Environmental and Engineering Geophysical Society
2020 – 2021 Coding Group Leader, GeoLatinas - Latinas in Earth and Planetary Sciences


  • Integrating time-lapse gravity, production, and geological structure data in a gas reservoir study

    2020 | Balza Morales, A., Li, Y.

    Interpretation, doi:10.1190/int-2019-0272.1

    Note: This publication resulted from Andrea's master thesis i.e. was prepared before GIM was founded.


    Time-lapse gravity is most commonly used to monitor fluid movement and is especially useful when monitoring water encroachment in a gas reservoir. Although time-lapse gravity data are directly sensitive to the fluid saturation changes in reservoirs, it is still necessary to integrate multiple types of data with complementary information to enhance the time-lapse gravity interpretation. When monitoring water-influx in a reservoir, the changes in water yield in production wells may directly indicate saturation changes with time and provide such complementary information about the areas of fluid movement. We present a workflow to invert a time-lapse gravity data set and production data to help monitor the edge water encroachment through a case study at the Sebei gas field in Western China. Three time-lapse gravity surveys were acquired between 2011 and 2013 and production data were also collected from 286 wells during the same period of time. We integrate the two data sets and the structural information in the reservoir through a framework of constrained time-lapse gravity inversion. In this workflow, we incorporate the information from the production data into the inversion by converting the gas and water yield into a reference model. We also incorporate geological structural information through spatially varying bound constraints. Through this approach, we construct a set of time-lapse density contrast models that are consistent with the time-lapse gravity data, production data, and structural information. The resultant density contrast models better delineate the regions of the reservoir with increased water influx and also enable us to produce improved porosity estimations in the reservoir.

    Cite as

    Balza Morales, A. and Li, Y. (2020): Integrating time-lapse gravity, production, and geological structure data in a gas reservoir study. Interpretation.

Conference contributions

  • Geothermal potential in the Rhine-Ruhr region - Integration of structural analysis and a preliminary magnetotelluric feasibility study

    2022 | Balza Morales, A., Gomez Diaz, E., Brehme, M., Kukla P. A., Wagner, F. M.

    European Geothermal Congress, Berlin, 17.-21. Oct. 2022


    Geothermal systems often occur in geologically complex structural environments with many closely spaced and intersecting faults. These commonly control the associated fluid flow needed for conventional geothermal reservoirs. One of the goals of the Innovative Training Network EASYGO - Efficiency and Safety in Geothermal Operations, aims to better characterize these systems in order to provide an initial assessment of geothermal potential in Europe. The Rhine-Ruhr region was selected as an area of interest for geothermal energy use in the context of the energy and heat transformation change in former coal mining areas. Here, Devonian carbonates and sandstones could play a role as potential reservoirs associated with karst systems or/and fracture zones. The magnetotelluric method has proven to be a useful tool in geothermal plays, where conductive bodies exist at depth. The goal of this study is to identify the structures and associated areas with enhanced fluid flow using structural analysis and magnetotelluric (MT) data. The initial areas chosen in the Rhine-Ruhr region were Rheindahlen, Lüdenscheid, and Aachen. Their local geology confirms favorable conditions for geothermal reservoir development. Additionally, these zones are strategic for MT data acquisition because of their distance from potential sources of anthropogenic noise. The study focuses on a quantitative method for fracture analysis attributes of potential reservoir rocks along with the integration of the geology, fault response modeling, and stress analysis. In addition, we plan to carry out an MT survey integrating the three areas of interest using prior geologic information. For this, we conducted a 3D forward modeling study to simulate the expected MT signals based on the initial structural analysis of the areas of interest. This was done as a feasibility study to predict if the calculated MT signal will be of sufficient signal-to-noise ratio to carefully design future MT acquisition campaigns. Results show favorable structural settings for the transport of fluids (e.g., fault intersection), where the structural component is marked by NW-SE striking normal faults and NE-SW oriented thrust faults with a strike slip-dilation component. Preliminary fracture analysis observed on the surface supports hints of density fracture zones for water circulation, but further studies should be conducted to see if these fractures propagate at depth. The synthetic MT study shows that a considerable signal is expected from conductive bodies within the range of 3,500 to 4,000 m depth. The characterization of the reservoir potential in these areas will facilitate similar studies in the entire Rhine-Ruhr region for a better understanding of the geothermal potential of North Rhine-Westphalia. This project has received funding from the European Unions Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 956965.

    Cite as

    Balza Morales, A. and Gomez Diaz, E. and Brehme, M. and Kukla P. A. and Wagner, F. M. (2022): Geothermal potential in the Rhine-Ruhr region - Integration of structural analysis and a preliminary magnetotelluric feasibility study. European Geothermal Congress, Berlin, 17.-21. Oct. 2022.
  • Towards structure-based joint geological-geophysical inversion for improved characterization of geothermal reservoirs

    2022 | Balza Morales, A., Gomez Diaz, E., Brehme, M., Kukla P. A., Wagner, F. M.

    EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022

    Conference website


    Proper characterization of geologic structures that host geothermal systems is crucial for the efficiency and safety of their energy production. This includes estimating layer boundaries, complex geologic features, and lithology through means of inversion and its regularization. However, existing advanced regularization techniques (e.g., geostatistical regularization, minimum-gradient support, etc.) fail to capture the complexity of 3D geological models including fault networks, fault-surface interactions, unconformities, and dome structures. Förderer et al (2021) propose a solution by means of structure-based inversion, which implements implicit geological modeling and low-dimensional parametrization to produce sharp subsurface interfaces in 2D. This work aims to extend their approach to image realistic and complex geometries in 3D. We continue with the example of electrical resistivity tomography (ERT) and synthetic data; however, this approach is aimed towards independent and joint inversion of geophysical methods that are commonly used in geothermal exploration such as magnetotellurics, gravity, and seismic techniques. The 3D geological model is created using GemPy, an open-source Python library, which constructs a structural geological model from interface points and orientations using an implicit approach based on co-kriging (de la Varga et al., 2019). Subsequently, the 3D model is discretized, and physical parameters are assigned using minimal pilot points that are then interpolated. We use pyGIMLi (Rücker et al., 2017), another open-source multi-method library for geophysical modelling and inversion, to perform a structure-based inversion, where we include the interface points in the primary model vector of the inversion to update these points iteratively to estimate a geological model in agreement with the geophysical observations. In this work, special focus is placed on the sensitivity of each model parameter. To maintain low parametrization and account for the increase in computational power, the cumulative sensitivity is calculated and tested under criteria to optimize the model updates. This is relevant for geometries where the interface and pilot points are more influential in one dimension than others. The workflow has also been adapted to include more complex structures that can be defined in 3D, especially those that reflect geothermal systems. This work is part of the Innovative Training Network EASYGO (, which aims to improve the efficiency and safety of geothermal operations but can be readily used in other applications. References: Förderer, A., Wellmann, F., and Wagner, F.M.: Geoelectrical imaging of subsurface discontinuities and heterogeneities using low-dimensional parameterizations, EGU General Assembly 2021, online, 19-30 Apr 2021, EGU21-10012, https//, 2021. de la Varga, M., Schaaf, A., and Wellmann, F., 2019. GemPy 1.0: open-source stochastic geological modeling and inversion, Geosci. Model Dev., 12, 1-32, doi 10.5194/gmd-12-1-2019. Rücker, C., Günther, T., Wagner, F.M., 2017. pyGIMLi: An open-source library for modelling and inversion in geophysics, Computers and Geosciences, 109, 106-123, doi 10.1016/j.cageo.2017.07.011.

    Cite as

    Balza Morales, A. and Gomez Diaz, E. and Brehme, M. and Kukla P. A. and Wagner, F. M. (2022): Towards structure-based joint geological-geophysical inversion for improved characterization of geothermal reservoirs. EGU General Assembly 2022, Vienna, Austria, 23-27 May 2022.
Back to team overview