Fracture transmissivity evolution due to silica dissolution/precipitation during geothermal heat extraction

Pandey, Sachchida Nand; Chaudhuri, Abhijit; Rajaram, Harihar; Kelkar, Sharad

doi:10.1016/j.geothermics.2015.06.011

Cited by 68 publications

(24 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With relations like the Kozeny-Carman equation (Eq. (9)), the change in permeability is calculated by relating the current permeability, K , based on the current porosity φ, to the initial or reference permeability, K 0 , based on the reference porosity φ 0 , (e.g., Schneider et al 1996;Wijngaarden et al 2011Wijngaarden et al , 2013Yasuhara et al 2012;Steefel et al 2015b;Xie et al 2015;Pandey et al 2014Pandey et al , 2015. This can be done as well with other porosity-permeability relationships, (e.g., Steefel et al 2015b;Steefel and Lasaga 1994;Steefel and AC 1990;Bernabe et al 2003;Civan 2001;Chadam et al 1986;Luquot and Gouze 2009;Marshall 1958;Pape et al 1999;Tsypkin and Woods 2005;Verma and Pruess 1988).…”

Section: Porosity-permeability Relations For (Bio-)geochemically Altementioning

confidence: 99%

See 1 more Smart Citation

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

Hommel¹,

Coltman²,

Class³

2018

Transp Porous Med

225

154

View full text Add to dashboard Cite

Reactive transport processes in a porous medium will often both cause changes to the pore structure, via precipitation and dissolution of biomass or minerals, and be affected by these changes, via changes to the material's porosity and permeability. An understanding of the pore structure morphology and the changes to flow parameters during these processes is critical when modeling reactive transport. Commonly applied porosity-permeability relations in simulation models on the REV scale use a power-law relation, often with slight modifications, to describe such features; they are often used for modeling the effects of mineral precipitation and/or dissolution on permeability. To predict the reduction in permeability due to biomass growth, many different and often rather complex relations have been developed and published by a variety of authors. Some authors use exponential or simplified Kozeny-Carman relations. However, many of these relations do not lead to fundamentally different predictions of permeability alteration when compared to a simple power-law relation with a suitable exponent. Exceptions to this general trend are only few of the porosity-permeability relations developed for biomass clogging; these consider a residual permeability even when the pore space is completely filled with biomass. Other exceptions are relations that consider a critical porosity at which the porous medium becomes impermeable; this is often used when modeling the effect of mineral precipitation. This review first defines the scale on which porosity-permeability relations are typically used and aims at explaining why these relations are not unique. It shows the variety of existing approaches and concludes with their essential features.

show abstract

Section: Porosity-permeability Relations For (Bio-)geochemically Altementioning

confidence: 99%

“…2.3 (Eq. (9)) (e.g., Schneider et al 1996;Wijngaarden et al 2011Wijngaarden et al , 2013Steefel et al 2015b;Xie et al 2015;Pandey et al 2014Pandey et al , 2015. Negligible geometry changes are commonly assumed (Φ s , D p ≈ constant).…”

Section: Kozeny-carman Relationmentioning

confidence: 99%

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

Hommel¹,

Coltman²,

Class³

2018

Transp Porous Med

225

154

View full text Add to dashboard Cite

show abstract

“…Simulations of a fracture in a limestone reservoir showed that the transmissivity of the reservoir is not monotonic with respect to time [ Pandey et al ., ]. In fractured granite reservoirs, simulations of the injection of undersaturated water created longer flow paths in the reservoir, a favorable condition for energy extraction [ Pandey et al ., ]. Guo et al .…”

Section: Discrete Fracture Network Model Descriptionmentioning

confidence: 99%

“…Simulations of a fracture in a limestone reservoir showed that the transmissivity of the reservoir is not monotonic with respect to time [Pandey et al, 2014]. In fractured granite reservoirs, simulations of the injection of undersaturated water created longer flow paths in the reservoir, a favorable condition for energy extraction [Pandey et al, 2015]. Guo et al [2016] modeled THMC effects on a fracture with an already heterogeneous aperture field and concluded that ignoring thermal stresses will overestimate energy production.…”

Section: Assumptions and Limitations Of The Modelmentioning

confidence: 99%

An analytical thermohydraulic model for discretely fractured geothermal reservoirs

Fox

Koch

Tester

2016

Water Resources Research

View full text Add to dashboard Cite

In discretely fractured reservoirs such as those found in Enhanced/Engineered Geothermal Systems (EGS), knowledge of the fracture network is important in understanding the thermal hydraulics, i.e., how the fluid flows and the resulting temporal evolution of the subsurface temperature. The purpose of this study was to develop an analytical model of the fluid flow and heat transport in a discretely fractured network that can be used for a wide range of modeling applications and serve as an alternative analysis tool to more computationally intensive numerical codes. Given the connectivity and structure of a fracture network, the flow in the system was solved using a linear system of algebraic equations for the pressure at the nodes of the network. With the flow determined, the temperature in the fracture was solved by coupling convective heat transport in the fracture with one‐dimensional heat conduction perpendicular to the fracture, employing the Green's function derived solution for a single discrete fracture. The predicted temperatures along the fracture surfaces from the analytical solution were compared to numerical simulations using the TOUGH2 reservoir code. Through two case studies, we showed the capabilities of the analytical model and explored the effect of uncertainty in the fracture apertures and network structure on thermal performance. While both sources of uncertainty independently produce large variations in production temperature, uncertainty in the network structure, whenever present, had a predominant influence on thermal performance.

show abstract

“…Pressure solution and chemical precipitation are found to be key mechanisms for permeability reduction in fractures [17][18][19][20], while chemical dissolution may increase permeability [21]. The strong temperature dependence of precipitation/dissolution kinetics of minerals also exerts significance on permeability evolution [22,23]. Effects of heterogeneity of mineral distribution and reaction rate on the rock dissolution process have been investigated using pore-scale reactive transport models based on the lattice Boltzmann method [24,25].…”

Section: Introductionmentioning

confidence: 99%

Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Permeability Evolution in a CO₂-Circulated Geothermal Reservoir

Tao

Elsworth

et al. 2019

Geofluids

View full text Add to dashboard Cite

The meager availability of water as a heat transfer fluid is sometimes an impediment to enhanced geothermal system (EGS) development in semi-arid regions. One potential solution is in substituting CO2 as the working fluid in EGS. However, complex thermo-hydro-mechanical-chemical (THMC) interactions may result when CO2 is injected into the geothermal reservoir. We present a novel numerical model to describe the spatial THMC interactions and to better understand the process interactions that control the evolution of permeability and the heat transfer area. The permeability and porosity evolution accommodate changes driven by thermo-hydro-mechanical compaction/dilation and mineral precipitation/dissolution. Mechanical and hydraulic effects are demonstrated to exert a small and short-term influence on permeability change, while the thermal effects are manifest in the intermediate and short-term influence. The most significant and long-term influence on permeability change is by chemical effects, where decreases in fracture permeability may be of the order of 10-5 due to calcite precipitation in fracture throats, which causes the overall permeability to reduce to 70% of the initial permeability. The initial pressure and temperature of the injected CO2 exerts an overriding influence on permeability. In particular, an increased temperature reduces the mineral precipitation in the fracture and enhances mineral dissolution within the matrix and pore but results in mechanical closure of the fractures. Optimizing injection pressure and temperature may allow the minimization of precipitation and the maximization of heat recovery.

show abstract

Fracture transmissivity evolution due to silica dissolution/precipitation during geothermal heat extraction

Cited by 68 publications

References 31 publications

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

An analytical thermohydraulic model for discretely fractured geothermal reservoirs

Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Permeability Evolution in a CO₂-Circulated Geothermal Reservoir

Contact Info

Product

Resources

About

Fracture transmissivity evolution due to silica dissolution/precipitation during geothermal heat extraction

Cited by 68 publications

References 31 publications

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

Porosity–Permeability Relations for Evolving Pore Space: A Review with a Focus on (Bio-)geochemically Altered Porous Media

An analytical thermohydraulic model for discretely fractured geothermal reservoirs

Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Permeability Evolution in a CO2-Circulated Geothermal Reservoir

Contact Info

Product

Resources

About

Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Permeability Evolution in a CO₂-Circulated Geothermal Reservoir