Enhanced Geothermal Systems (EGS): Hydraulic Fracturing in a Thermo-Poroelastic Framework

Loret, Benjamin

doi:10.1007/978-3-319-94217-9_7

Cited by 3 publications

(2 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The decrease of compressional and shear wave velocities was attributed to thermal fracturing at Fenton Hill, New Mexico (Pearson et al., 1983). However, thermal fracturing has not gained much attention at many EGS sites when compared with hydraulic fracturing or shearing (e.g., Brown et al., 2012; Evans, 2005; Evans et al., 2005), even though thermoporoelasticity has been recognized when water injection with hydraulic stimulation causes significant cooling (Loret, 2019).…”

Section: Introductionmentioning

confidence: 99%

Scaling Behavior of Thermally Driven Fractures in Deep Low‐Permeability Formations: A Plane Strain Model With 1‐D Heat Conduction

Chen

Zhou

2022

JGR Solid Earth

View full text Add to dashboard Cite

Injection of cold fluids through/into deep formations may cause significant cooling, thermal stress, and possible thermal fracturing. In this study, the thermal fracturing of low‐permeability formations under one‐dimensional heat conduction was investigated using a plane strain model. Dimensionless governing equations, with dimensionless fracture length scriptL $\mathcal{L}$, aperture normalΩ ${\Omega}$, spacing scriptD $\mathcal{D}$, time τ $\tau $, and effective confining stress scriptT $\mathcal{T}$, were derived. Solution of single thermal fracture was derived analytically, while solution of multiple fractures with constant (or dynamic) spacing were obtained using the displacement discontinuity method (and stability analysis). For single fracture, scriptL(τ,T) $\mathcal{L}(\tau ,\mathcal{T})$ increases nonlinearly with τ $\sqrt{\tau }$ and then transitions to scaling law scriptL=f(scriptT)τ $\mathcal{L}=f(\mathcal{T})\sqrt{\tau }$, indicating that late‐time fracture length increases linearly with the square root of cooling time. For constantly spaced fractures, scriptL(τ,T,D) $\mathcal{L}(\tau ,\mathcal{T},\mathcal{D})$ deviates from the single‐fracture solution at a later τ $\tau $ for a larger scriptD $\mathcal{D}$, showing slower propagation under inter‐fracture stress interaction. For dynamically spaced fractures, fracture arrest induced by stress interaction was determined by the stability analysis; the fully transient solution provides evolution of dimensionless fracture length, spacing, aperture, and pattern; a similar scaling law, scriptL=f′(scriptT)τ $\mathcal{L}={f}^{\prime }(\mathcal{T})\sqrt{\tau }$ with f′(T)

show abstract

Section: Introductionmentioning

confidence: 99%

Scaling Behavior of Thermally Driven Fractures in Deep Low‐Permeability Formations: A Plane Strain Model With 1‐D Heat Conduction

Chen

Zhou

2022

JGR Solid Earth

View full text Add to dashboard Cite

show abstract

“…Scholars have carried out the influence of pumping and irrigation well layout on groundwater flow field and temperature field (Wang et al 2016), the influence of pumping and irrigation well distribution mode and pumping and irrigation well water quantity on heat transfer characteristics of underground heat exchanger wells (Ma et al 2019(Ma et al , 2020, and the application of numerical simulation of water and heat transport to optimize pumping and irrigation well layout of groundwater source heat pump system (Jin et al 2012), Numerical simulation of water-heat coupling of single well ground water source heat pump in T2Well (Li u et al 2020) and optimization of reasonable well spacing and layout of shallow source heat pump simulated by sand tank-taking Jiuxi in Fenglin as an example (Ma et al 2018). Scholars have carried out sustainable electricity generation from an Enhanced Geothermal System considering reservoir heterogeneity and water losses with a discrete fractures model (Joël et al 2021)，Enhanced Geothermal Systems (EGS): hydraulic fracturing in a thermo-poroelastic framework (Loret 2019) and modified zipper fracturing in enhanced geothermal system reservoir and heat extraction optimization via orthogonal design (Yu et al 2020). To sum up, although some achievements have been made in the study of geothermal well temperature, there are few reports on the complex model of thermal recovery efficiency optimization under different geothermal well layout conditions.…”

Section: Introductionmentioning

confidence: 99%

Study On Optimization Mechanism of Thermal Recovery Efficiency Under Different Geothermal Well Layout Conditions

Gao

2021

Preprint

View full text Add to dashboard Cite

Efficient exploitation of geothermal energy is a hot issue concerned by scientific and engineering circles. The layout of different injection wells and production wells directly affects the temperature field of production wells and rock mass. In order to study the thermal recovery efficiency under different geothermal well layout conditions, based on the conceptual model of two injection wells and two production wells, a 3DEC program is used to calculate and analyze the influence of the different water inlet and water inlet of two injection wells and two production wells on the temperature field of rock mass, geothermal wells and the water temperature of production wells outlet. The results show that: (1) After the model injection wells are switched with the production wells, the temperature gradients of rock mass, production wells and injection wells are almost the same in numerical value and opposite in direction. (2) Production wells are set on the left side and injection wells are set on the right side of the model, and the injection wells and production wells are set at intervals; The temperature field of rock mass on both sides of the edge forms a central symmetry; The temperature gradient of rock mass from the middle to the edge is smaller and smaller, which indicates that the heat transfer speed of rock mass from the middle to the edge is slower and slower. Because the thermal superposition of adjacent injection wells and production wells through the rock mass between them is dominant, the water temperature at the outlet of production wells is the highest; In the interval water injection well and production well, the heat convection between water flow and rock is dominant, which makes the water temperature of production well outlet drops. (3) According to the water temperature at the outlet of production well, the optimal order of the model is working condition 3 > working condition 1 = working condition 2 > working condition 4, and the time to reach a steady state is the shortest in working condition 3 and the longest in working condition 4. The research results can provide important theoretical and practical reference for optimizing the layout of geothermal wells in efficient geothermal exploitation.

show abstract

A new mathematical modeling approach for thermal exploration efficiency under different geothermal well layout conditions

Gao

Shi

2021

Sci Rep

View full text Add to dashboard Cite

The water temperature at the outlet of the production well is an important index for evaluating efficient geothermal exploration. The arrangement mode of injection wells and production wells directly affects the temperature distribution of the production wells. However, there is little information about the effect of different injection and production wells on the temperature field of production wells and rock mass, so it is critical to solve this problem. To study the influence mechanism of geothermal well arrangement mode on thermal exploration efficiency, the conceptual model of four geothermal wells is constructed by using discrete element software, and the influence law of different arrangement modes of four geothermal wells on rock mass temperature distribution is calculated and analyzed. The results indicated that the maximum water temperature at the outlet of the production well was 84.0 °C due to the thermal superposition effect of the rock mass between the adjacent injection wells and between the adjacent production wells. Inversely, the minimum water temperature at the outlet of the production well was 50.4 °C, which was determined by the convection heat transfer between the water flow and the rock between the interval injection wells and the interval production wells. When the position of the model injection well and production well was adjusted, the isothermal number line of rock mass was almost the same in value, but the direction of water flow and heat transfer was opposite. The study presented a novel mathematical modeling approach for calculating thermal exploration efficiency under various geothermal well layout conditions.

show abstract

Enhanced Geothermal Systems (EGS): Hydraulic Fracturing in a Thermo-Poroelastic Framework

Cited by 3 publications

References 57 publications

Scaling Behavior of Thermally Driven Fractures in Deep Low‐Permeability Formations: A Plane Strain Model With 1‐D Heat Conduction

Scaling Behavior of Thermally Driven Fractures in Deep Low‐Permeability Formations: A Plane Strain Model With 1‐D Heat Conduction

Study On Optimization Mechanism of Thermal Recovery Efficiency Under Different Geothermal Well Layout Conditions

A new mathematical modeling approach for thermal exploration efficiency under different geothermal well layout conditions

Contact Info

Product

Resources

About