Static and Dynamic Reservoir Characterization of the Heterogeneous Upper Jurassic Carbonate Reservoir Beneath the German Alpine Foreland Basin: A case study on a Premature Thermal Breakthrough Southeast of Munich

by Mohamed Fadel
Cumulative thesis
Date of Examination:2024-09-12
Date of issue:2024-11-12
Advisor:Prof. Dr. Inga Moeck
Referee:Prof. Dr. Inga Moeck
Referee:Prof. Dr. Martin Sauter
Persistent Address: http://dx.doi.org/10.53846/goediss-10837

 

 

Files in this item

Name:Fadel (2024).pdf
Size:168.Mb
Format:PDF
Description:Cumulative Thesis
Name:Interference test model.gif
Size:29.3Mb
Format:GIF
Description:Short video on the interference test model conducted in the study

The following license files are associated with this item:

Abstract

English

This study investigates the causes of an unexpected Premature Thermal Breakthrough (PTB) in a geothermal doublet located southeast of Munich. The PTB occurred after only three years of operation, which contradicts previous reservoir models projecting stable production temperatures for fifty years. The PTB poses a significant risk to geothermal system sustainability in the Upper Jurassic carbonate (Malm) reservoir, whose thermal and hydraulic behavior is controlled by complex subsurface permeability structures. To define the causes of the PTB, an integrated approach is utilized, combining multi-scale geological and geophysical data with well testing and modeling approaches. Analysis of 3D seismic data, Formation Micro Image logs, and production logging data reveals key structural features controlling the reservoir's permeability. The production well penetrates an NNW-SSE fracture corridor, which is coupled with a fault damage zone penetrated by the injection well. The fracture network of both features promotes anisotropic permeability, forming a direct hydraulic communication that reduces the thermal sweep efficiency in the reservoir between the injector and the producer. Pressure Transient Analysis and interference tests delineate a fractured reservoir behavior, with a linear flow regime reflecting the fracture-induced permeability anisotropy. This research emphasizes the importance of utilizing localized, fit-for-purpose dynamic models to capture reservoir heterogeneities that regional models may overlook. Through the development of a conceptual hydrogeological model, incorporating the reservoir permeability structure, and defining the reservoir system type, this study provides insights into improving dynamic reservoir simulations and mitigating PTB risks in comparable geothermal systems.
Keywords: carbonate reservoir characterization; thermal breakthrough; fracture-controlled reservoirs; North Alpine Foreland Basin; Upper Jurassic carbonates; pressure transient analysis; discreet fracture network modelling; well test; double porosity models
 
Statistik