Predictability and controlling factors of overpressure in the North Alpine Foreland Basin, SE Germany: An interdisciplinary post-drill analysis of the Geretsried GEN-1 Deep Geothermal Well
The North Alpine Foreland Basin in SE Germany Germany’s most active deep geothermal province. However, in its southern and eastern part the basin is considerably overpressured, which is a significant challenge for drilling deep geothermal wells. In this study, we combine drilling data and velocity-based pore pressure analyses with 3D basin modelling to assess the predictability and controlling factors of overpressure in the sub-regional context (area of 80 km x 50 km) around the Geretsried GEN-1 well, a deep geothermal exploration well in the southern part of the North Alpine Foreland Basin in SE Germany. Drilling data and velocity-based pore pressure analyses indicate overpressure maxima in the Lower Oligocene (Rupelian and Schoeneck Formation) and up to mild overpressure in the Upper Oligocene (Chattian) and Upper Cretaceous, except for the hydrostatically pressured northwestern part of the study area. 3D basin modelling calibrated to four hydrocarbon wells surrounding the Geretsried GEN-1 well demonstrates the dominating role of disequilibrium compaction and low permeability units related to overpressure generation in the North Alpine Foreland Basin. However, secondary overpressure generation mechanisms are likely contributing. Also, the impact of Upper Cretaceous shales, which are eroded in the northwestern part of the study area, on overpressure maintenance is investigated. The calibrated basin model is tested against the drilling history and velocity (VSP) data-based pore pressure estimate of the Geretsried GEN-1 well and reveals that pore pressure prediction is generally possible using 3D basin modelling in the North Alpine Foreland Basin, but should be improved with more detailed analysis of lateral drainage systems and facies variations in the future. The results of the study are of relevance to future well planning and drilling as well as to geomechanical modelling of subsurface stresses and deep geothermal production in the North Alpine Foreland Basin.
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Posted 06 Jul, 2020
On 11 Jul, 2020
On 06 Jul, 2020
On 01 Jul, 2020
On 30 Jun, 2020
On 30 Jun, 2020
Received 26 Jun, 2020
On 26 Jun, 2020
On 18 Jun, 2020
Received 18 Jun, 2020
Invitations sent on 17 Jun, 2020
On 17 Jun, 2020
On 16 Jun, 2020
On 15 Jun, 2020
On 15 Jun, 2020
On 26 May, 2020
Received 29 Apr, 2020
Received 28 Apr, 2020
Received 18 Apr, 2020
On 16 Apr, 2020
On 16 Apr, 2020
Invitations sent on 15 Apr, 2020
On 15 Apr, 2020
On 09 Apr, 2020
On 08 Apr, 2020
On 08 Apr, 2020
On 08 Apr, 2020
Predictability and controlling factors of overpressure in the North Alpine Foreland Basin, SE Germany: An interdisciplinary post-drill analysis of the Geretsried GEN-1 Deep Geothermal Well
Posted 06 Jul, 2020
On 11 Jul, 2020
On 06 Jul, 2020
On 01 Jul, 2020
On 30 Jun, 2020
On 30 Jun, 2020
Received 26 Jun, 2020
On 26 Jun, 2020
On 18 Jun, 2020
Received 18 Jun, 2020
Invitations sent on 17 Jun, 2020
On 17 Jun, 2020
On 16 Jun, 2020
On 15 Jun, 2020
On 15 Jun, 2020
On 26 May, 2020
Received 29 Apr, 2020
Received 28 Apr, 2020
Received 18 Apr, 2020
On 16 Apr, 2020
On 16 Apr, 2020
Invitations sent on 15 Apr, 2020
On 15 Apr, 2020
On 09 Apr, 2020
On 08 Apr, 2020
On 08 Apr, 2020
On 08 Apr, 2020
The North Alpine Foreland Basin in SE Germany Germany’s most active deep geothermal province. However, in its southern and eastern part the basin is considerably overpressured, which is a significant challenge for drilling deep geothermal wells. In this study, we combine drilling data and velocity-based pore pressure analyses with 3D basin modelling to assess the predictability and controlling factors of overpressure in the sub-regional context (area of 80 km x 50 km) around the Geretsried GEN-1 well, a deep geothermal exploration well in the southern part of the North Alpine Foreland Basin in SE Germany. Drilling data and velocity-based pore pressure analyses indicate overpressure maxima in the Lower Oligocene (Rupelian and Schoeneck Formation) and up to mild overpressure in the Upper Oligocene (Chattian) and Upper Cretaceous, except for the hydrostatically pressured northwestern part of the study area. 3D basin modelling calibrated to four hydrocarbon wells surrounding the Geretsried GEN-1 well demonstrates the dominating role of disequilibrium compaction and low permeability units related to overpressure generation in the North Alpine Foreland Basin. However, secondary overpressure generation mechanisms are likely contributing. Also, the impact of Upper Cretaceous shales, which are eroded in the northwestern part of the study area, on overpressure maintenance is investigated. The calibrated basin model is tested against the drilling history and velocity (VSP) data-based pore pressure estimate of the Geretsried GEN-1 well and reveals that pore pressure prediction is generally possible using 3D basin modelling in the North Alpine Foreland Basin, but should be improved with more detailed analysis of lateral drainage systems and facies variations in the future. The results of the study are of relevance to future well planning and drilling as well as to geomechanical modelling of subsurface stresses and deep geothermal production in the North Alpine Foreland Basin.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
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Figure 8
Figure 9
Figure 10