GeoThermal Engineering GmbH

Karlsruhe, Germany

GeoThermal Engineering GmbH

Karlsruhe, Germany
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Loschan G.,GeoThermal Engineering GmbH | Emmerich K.,Karlsruhe Institute of Technology | Reinhold C.,Rhein Petroleum GmbH | Reinecker J.,GeoThermal Engineering GmbH
Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften | Year: 2017

Formations containing swellable clay minerals are often critical for drilling operations. In the Upper Rhine Graben, this problem especially applies to the Tertiary formations. For a more detailed characterisation of the specific formations and to assess potential correlations between borehole instabilities and clay mineralogy, 54 cutting samples from four different wells in the northern Upper Rhine Graben were subject to a clay mineralogical analysis by X-ray diffraction and measurements of the cation exchange capacity. The results show pure smectite only in the top section of the Hydrobia Beds (Miocene). With increasing depth, a transition to illite/smectite interstratified minerals with a decreasing share of smectite is observed, corresponding to a decreasing cation exchange capacity down to the Septarian Clay (Lower Oligocene). Whether this is a diagenetic effect or due to an initially higher smectite content in the Hydrobia Beds could not be finally clarified. Based on most recent temperature measurements, the maximum temperature for pure smectite in the Hydrobia Beds is at least 69 °C. One possible approach to explain the advanced illitisation within the Hydrobia Beds compared to older formations is considered the higher availability of potassium due to stronger dissolution of potassium feldspars resulting from higher water contents and slight overpressures. The results show that the given borehole instabilities cannot be correlated with the clay mineralogy. Most probably, they mainly result from specific stress conditions, high borehole inclinations and mechanical strains during drilling operations. However, the permanent share of smectite in interstratified minerals of up to 20 % may be a contributing factor in causing borehole instabilities. © 2017 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.

Heidbach O.,German Research Center for Geosciences | Hergert T.,Karlsruhe Institute of Technology | Reinecker J.,GeoThermal Engineering GmbH | Reiter K.,German Research Center for Geosciences | And 3 more authors.
International Workshop on Geomechanics and Energy: The Ground as Energy Source and Storage | Year: 2013

We present a revised and extended database of the orientation of maximum horizontal stress SH and the tectonic regime compiled for Switzerland. The analysis of this compilation reveals that the SH orientation is perpendicular to the topography gradient of the Alps, the Moho and the basement and thus swings from a N-S orientation in the east by 40° counter clockwise to the southwest. The SH orientation shows no statistically significant changes with depth, but at a few individual boreholes the SH orientation changes at various depth significantly indicating local mechanical decoupling. To obtain a spatially continuous description of all stress tensor components for a rock volume in Northern Switzerland we present a semigeneric geomechanical-numerical model. We find that the total stress ratio SH/Sh (with Sh being the minimum horizontal stress) within the Mesozoic cover contrasts significantly between shale units (e.g. Opalinus Clay, 1.2

Law R.,GeoThermal Engineering GmbH
Chemical Engineer | Year: 2010

Geothermal energy could become an important source of renewable energy in the UK as the world has come to realize the importance of sustainability, climate change and energy security. The increasing interest, coupled with increasingly sophisticated drilling technology, has led to projects drilling to greater depths to enable development in countries that have never seen geothermal power plants before. Enhanced geothermal systems (EGS) is the generic term used to cover a range of technologies used when generating power from deep geothermal resources. Binary geothermal power plants, which use a working fluid with a lower boiling point than water, are becoming popular in Europe. A significant advantage of the deeper geothermal systems is that they are normally tapping into hot dry rock, where very little existing geothermal fluid is present. This should greatly reduce the aggressiveness of the fluid that eventually circulates through the injection and abstraction wells.

Rohrer L.,University of Heidelberg | Wenke A.,GeoThermal Engineering GmbH | Zuhlke R.,University of Heidelberg | Spath F.,Uberlandwerk Gross Gerau GmbH
74th European Association of Geoscientists and Engineers Conference and Exhibition 2012 Incorporating SPE EUROPEC 2012: Responsibly Securing Natural Resources | Year: 2012

The permocarboniferous sediments in the northern upper rhine rift valley represent a possible geothermal reservoir. Depth and temperature data from hydrocarbon exploration in the 1970-1980ies prove this. A integrated structural, stratigraphic and facial model based on seismic data is build. Integration of well data and outcrop analogue studies leads to higher resolution. The static 3D-model is the base for the following thermo-hydraulic simulation while geothermal usage. The 3D-model shows large fault systems with high throws. The outcrop studies indicate coarse sediments with high lateral continuity and good poroperm properties. The thermohydraulic simulation of geothermal usage shows a sustainible reservoir unit with intraformational flow and connectivity along fault systems.

Ziegler M.O.,Helmholtz Center Potsdam | Ziegler M.O.,University of Potsdam | Heidbach O.,University of Potsdam | Reinecker J.,GeoThermal Engineering GmbH | And 3 more authors.
Solid Earth | Year: 2016

The knowledge of the contemporary in situ stress state is a key issue for safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state is limited and often not available for the areas of interest. Therefore 3-D geomechanical-numerical modelling is used to estimate the in situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scale between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3-D geomechanical-numerical approach which provides a state-of-the-art model of the stress field for a reservoir-scale area from widely scattered data records. Therefore, we first use a large-scale regional model which is calibrated by available stress data and provides the full 3-D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller-scale model located within the large-scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. As an example of application, we estimate the scalar values for slip tendency and fracture potential from the model results as measures for the criticality of fault reactivation in the reservoir-scale model. The modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude estimates needed for a more reliable model calibration. This leads to the conclusion that at this stage the model's reliability depends only on the amount and quality of available stress information rather than on the modelling technique itself or on local details of the model geometry. Any improvements in modelling and increases in model reliability can only be achieved using more high-quality data for calibration. © 2016 Author(s).

Bauer F.U.,University of Heidelberg | Bauer F.U.,University of Bergen | Glasmacher U.A.,University of Heidelberg | Ring U.,University of Stockholm | And 3 more authors.
International Journal of Earth Sciences | Year: 2015

To determine the long-term landscape evolution of the Albertine Rift in East Africa, low-temperature thermochronology was applied and the cooling history constrained using thermal history modelling. Acquired results reveal (1) “old” cooling ages, with predominantly Devonian to Carboniferous apatite fission-track ages, Ordovician to Silurian zircon (U–Th)/He ages and Jurassic to Cretaceous apatite (U–Th–Sm)/He ages; (2) protracted cooling histories of the western rift shoulder with major phases of exhumation in mid-Palaeozoic and Palaeogene to Neogene times; (3) low Palaeozoic and Neogene erosion rates. This indicates a long residence time of the analysed samples in the uppermost crust, with the current landscape surface at a near-surface position for hundreds of million years. Apatite He cooling ages and thermal history models indicate moderate reheating in Jurassic to Cretaceous times. Together with the cooling age distribution, a possible Albertine high with a distinct relief can be inferred that might have been a source area for the Congo Basin. © 2015 Springer-Verlag Berlin Heidelberg

Yusman W.,GeoThermal Engineering GmbH | Yusman W.,Bandung Institute of Technology | Viridi S.,Nuclear Physics and Biophysics | Viridi S.,Bandung Institute of Technology | And 2 more authors.
IOP Conference Series: Earth and Environmental Science | Year: 2016

The non-discharges geothermal wells have been a main problem in geothermal development stages and well discharge stimulation is required to initiate a flow. Air compress stimulation is one of the methods to trigger a fluid flow from the geothermal reservoir. The result of this process can be predicted by using by the Af / Ac method, but sometimes this method shows uncertainty result in several geothermal wells and also this prediction method does not take into account the flowing time of geothermal fluid to discharge after opening the well head. This paper presents a simulation of non-discharges well under air compress stimulation to predict well behavior and time process required. The component of this model consists of geothermal well data during heating-up process such as pressure, temperature and mass flow in the water column and main feed zone level. The one-dimensional transient numerical model is run based on the Single Fluid Volume Element (SFVE) method. According to the simulation result, the geothermal well behavior prediction after air compress stimulation will be valid under two specific circumstances, such as single phase fluid density between 1 - 28 kg/m3 and above 28.5 kg/m3. The first condition shows that successful well discharge and the last condition represent failed well discharge after air compress stimulation (only for two wells data). The comparison of pf values between simulation and field observation shows the different result according to the success discharge well. Time required for flow to occur as observed in well head by using the SFVE method is different with the actual field condition. This model needs to improve by updating more geothermal well data and modified fluid phase condition inside the wellbore.

Kreuter H.,GeoThermal Engineering GmbH | Schrage C.,GeoThermal Engineering GmbH
Transactions - Geothermal Resources Council | Year: 2010

Biogas and geothermal are both renewable energy sources with a large potential to contribute to the EU target of increasing the share of renewable energy to 20 % until 2020. Currently, the worldwide first hybrid power concept coupling a biogas and a geothermal power plant is implemented in Neuried in the Upper Rhine Graben. The biogas plant is operational since 2007; the geothermal project will start drilling the first well in 2010. From a technical point of view, the hybrid approach considerably increases the power generation efficiency. In combination with the integrated heat use concept, it reduces CO2-emissions by up to 46,000 tons per year, supports the local energy supply and disposes of a diversified revenue structure. The pioneer hybrid plant Neuried can serve as the general proof of concept for this environmentally sound way of energy production.

Baisch S.,Q con GmbH | Schrage C.,GeoThermal Engineering GmbH | Kreuter H.,GeoThermal Engineering GmbH
Transactions - Geothermal Resources Council | Year: 2010

During the last years, exploitation of hydro-geothermal energy has attracted increasing attention in Germany. In several cases, felt earthquake activity occurred in the vicinity of geothermal sites after the systems went into operation. Although the observed earthquakes exhibited small magnitudes only, some of them were felt by the local population. No significant material damage was reported, however major concerns exist in the public regarding the safety of geothermal power production. The public perception of the seismic risk as well as the lack of regulative standards impedes the development of geothermal projects in Germany. Several hydrothermal projects are currently put on hold due to seismic risk concerns, and a quantitative assessment of the seismic risk has become mandatory. The basis for a seismic risk analysis is a detailed understanding of the physical processes associated with induced seismicity. This allows numerical simulations of reservoir operations and their impact on seismic risk. In combination with reaction plans (traffic light system), where hydraulic operations are modified or even stopped when induced earthquakes become to strong, the seismic risk can be controlled and minimized.

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