Investigative Coupled Thermo-Hydro-Mechanical Modelling Approach for Geothermal Heat Extraction through Multistage Hydraulic Fracturing from Hot Geothermal Sedimentary Systems

Muhammad Haris,Michael Z Hou,Jiashun Luo,Muhammad Khurram Zahoor,Jianxing Liao,Wentao Feng

doi:10.3390/en13133504

Muhammad Haris, Michael Z Hou + Show 4 more

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https://doi.org/10.3390/en13133504

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Abstract

The meaningful utilization of artificially created multiple fractures in tight formations is associated with the performance behavior of such flow channels, especially in the case of thermal energy extraction from sedimentary geothermal system. In this study, an innovative idea is presented to develop a numerical model for geothermal energy production based on concrete physical performance of an artificially created tensile multi-fracture system in a simplified manner. The state-of-the-art software FLAC3Dplus-TOUGH2MP-TMVOC are integrated to develop a coupled thermo-hydro-mechanical (THM) fictive model for constructing a multi-fracture scheme and estimating heat extraction performance. By incorporating the actual fracture width of newly created subsequent fracture under the effect of stress shadow, cubic law is implemented for fluid flow and geothermal energy production. The results depict that fracture spacing plays a vital role in the energy contribution through multiple fractures. Afterwards, a field case study to design huge multiple hydraulic fractures was performed in the geothermal well GB X1 in North Germany. The attenuation of fracture propagation becomes more significant when massive multiple fracturing operation is performed especially in the case of lower fracture spacing. The fictive model results will be extended to study the geothermal utilization of the North German basin through massive multiple fractures in our future work.

Highlights

The interminable increase in energy demand has triggered the exploitation of unconventional energy resources in recent times
10–12 hydraulic fractures to both sides of the well the large geothermal area by creating 10–12 hydraulic fractures to both sides of the wellbased basedon theon schematic fracture pattern
An innovative enhanced geothermal system (EGS) concept by combining artificially created multiple hydraulic fractures with two horizontal wells for harnessing geothermal energy based on concrete physical fractures with two horizontal wells for harnessing geothermal energy based on concrete physical performance of the fracture system was presented

Summary

Introduction

The interminable increase in energy demand has triggered the exploitation of unconventional energy resources in recent times. There is an immense need of utilizing renewable energy resources along with dependency on natural fossil fuels In this recent era of global warming, researchers are more focused to work on efficient, environmentally friendly, and renewable energy resources. Based on these requirements, geothermal energy is among the leading positions, as it provides heat energy which is independent of weather and at the same time is sustainable, renewable, and virtually without greenhouse gas emissions [1,2,3,4,5]. Geothermal energy evolves due to two sources, (a) transfer of energy from hot molten core to exterior of the earth, (b) decay of the radio-active elements [6]. The interior of earth has a temperature above 4000 K (approx.) [7] and is considered to be a huge source of geothermal

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