Productivity enhancement of geothermal wells through fault zones: Efficient numerical evaluation of a parameter space for the Upper Jurassic aquifer of the North Alpine Foreland Basin. (September 2021)

• Record Type: Journal Article
• Authors: Konrad, Florian; Savvatis, Alexandros; Degen, Denise; Wellmann, Florian; Einsiedl, Florian; Zosseder, Kai
• Is Part Of: Geothermics. Volume 95(2021)
• Publication Date: 2021-09
• Subjects: Numerical simulation -- Geothermal energy -- Pressure transient analysis -- Parametric study -- Fault zone -- Malm -- Molasse basin -- Productivity index -- Reduced basis method; Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2021.102119
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: Through comparison of pairs of numerically simulated pressure curves of pumping tests the influence of fault zones on the productivity index of a geothermal well can be quantified. Quality controlled model order reduction (by the use of the Reduced Basis method) of a calibrated Finite-Element model of a fault zone within the Upper Jurassic aquifer increases simulation speeds by a factor of 10 4 . Hydraulically active fault zones can significantly improve the wells productivity index while a radial flow regime is present. Hydraulically active thickness of a fault zone of 50 meters provides a good representation of flow field observations in the greater area of Munich. uja_faultzones is an open source Python tool to efficiently simulate pressure curves of pumping tests for fault zones of the Upper Jurassic aquifer. Abstract: Fault zones (FZ) are major components of geothermal exploration concepts for the Southern German Upper Jurassic aquifer (UJA). Because these sections of possibly favorable hydraulic properties can be hidden in pumping test data, their explorational importance with respect to well productivity is still debated. In this work, the effect of hydraulically active FZ on the well-productivity-index (PI) is quantified in dependency of the UJA parameter space using numerical modeling and the Reduced Basis method. Results suggest that hidden FZ can increase PI significantly, while a hydraulically active FZ thickness of ≥ 100 m is unlikely for the Upper Jurassic aquifer.