Transitions of Dissolution Patterns in Rough Fractures

Wang, Ting; Hu, Ran; Yang, Zhibing; Zhou, Chen‐Xing; Chen, Yi‐Feng; Zhou, Chuangbing

doi:10.1029/2021wr030456

Cited by 18 publications

(15 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2021; Wang et al. 2022). Specifically, when a salt is dissolving in a liquid, dynamic mass transport phenomena around the dissolving solid exist, changing the shape of the solid body of the salt.…”

Section: Introductionsupporting

confidence: 55%

Theoretical and numerical studies on dissolution of horizontal salt body and pattern formation incorporated with a dynamic moving interface

Hong

Kim

2023

J. Fluid Mech.

View full text Add to dashboard Cite

The dissolution of a horizontal salt body is theoretically and numerically investigated by considering the coupled dynamics of the dissolution reaction and the diffusive and convective mass transfer at the salt surface. To take into account the nature of the recessing salt surface and the dissolution-driven convection, a dynamic moving boundary condition coupled with a dissolution reaction are employed By employing a newly derived moving interface condition and parameters, a theoretical analysis predicts the onset of gravitational instability, suggesting scaling relationships between parameters to describe the onset of instability (in transport-dominant (Damkholer number $Da \to \infty $ and Rayleigh number $Ra > {10^5}$ ), onset time ${\tau _d}\sim R{a^{ - 2/3}}$ and ${\tau _d}\sim (RaDa)^{1/4}$ for reaction-dominant regimes $(Da \to 0)$ ). The scaling relationships on dissolution (the average height change, $\Delta {h_{avg}}\sim \sqrt \tau $ for the diffusion-dominant regime and $\Delta {h_{avg}}\sim R{a^{0.79/3}}{\tau ^{0.86}}$ for the convection-dominant regime) are also suggested to explain the pattern formation. Under a convective mass transfer condition, the concentration gradient of the solute developed during the recession of the salt surface results in an adverse density gradient, which causes gravitational instability motion and finally determines the formation of a dissolution pattern. In addition, two-dimensional and three-dimensional numerical simulations visualize dissolution-driven convective flow fields, the recession of the liquid-solid interface and pattern formation on the dissolving interface. Theoretical and numerical analyses of the dissolution process suggest that the control of gravitational instability is important to prevent or enhance dissolution pattern formation. This systematic parameter study provides a deep understanding of the effect of gravitational instability on convection-driven dissolution in a horizontal geometry.

show abstract

Section: Introductionsupporting

confidence: 55%

Theoretical and numerical studies on dissolution of horizontal salt body and pattern formation incorporated with a dynamic moving interface

Hong

Kim

2023

J. Fluid Mech.

View full text Add to dashboard Cite

show abstract

“…When the advection and reaction rates are comparable, the wormhole pattern emerges, and the permeability increases significantly. A large number of studies have indicated how the key factors, including flow rate (Detwiler et al., 2003; Starchenko et al., 2016; Szymczak & Ladd, 2009; Upadhyay et al., 2015; Wang et al., 2022; Xu et al., 2020), fluid reactivity (Deng et al., 2020), multiple fluids (Jiménez‐Martínez et al., 2020; Ott & Oedai, 2015), initial geometry (Cheung & Rajaram, 2002; Hanna & Rajaram, 1998), mineral heterogeneity (Al‐Khulaifi et al., 2017; Deng et al., 2017; You & Lee, 2022), and stress conditions (Roded et al., 2018; Spokas et al., 2018), affect the dissolution patterns. However, the role of gravity in dissolution dynamics is not well understood.…”

Section: Introductionmentioning

confidence: 99%

“…Under a no‐external‐flowing condition, experimental and numerical studies showed that in a horizontal configuration, the buoyancy‐driven convection reproduces beautiful patterns like scallops, grooves, and rillenkarren on the upper surface (Cohen et al., 2020; Favier et al., 2019; Sullivan et al., 1996; Thomas & Armistead, 1968). Under a flowing condition, the interplay between buoyancy‐driven convection and forced convection would generate parallel grooves channels along the bulk flow direction (Wang et al., 2022) and significantly affect the local dissolution rate. Induced by this interplay, an interesting phenomenon, namely dissolution hotspot (Hu et al., 2021), has been recently observed and quantified in radial horizontal fractures.…”

Section: Introductionmentioning

confidence: 99%

On the Role of Gravity in Dissolving Horizontal Fractures

Zhou

et al. 2023

JGR Solid Earth

Self Cite

View full text Add to dashboard Cite

Fractures are ubiquitous in geological systems. As reactive fluid flow through a fracture, dissolution of the fracture walls may occur, thus altering the fracture aperture and increasing permeability. It has been recognized that gravity plays an important role in dissolving vertical fractures due to buoyancy‐driven convection. However, the role of gravity in dissolving horizontal fractures is not well understood. Here, we combine microfluidics/Hele‐Shaw experiments and a numerical method to study how the interplay of buoyancy‐driven convection and forced convection controls dissolution dynamics and permeability increase in horizontal fractures. We first develop the micro‐continuum approach by incorporating the gravitational effects, and then, we perform experiments to validate our method, confirming that the method can well capture gravitational effects on dissolution. Through 3D simulations, we find that buoyancy‐driven convection breaks the symmetry of dissolution on the upper and lower surfaces. We employ a symmetry index to identify three dissolution regimes. As the importance of gravity increases (Ri increases), the dissolution regime shifts from forced convection to mixed convection and to natural (or buoyancy‐driven) convection. We establish a link between these dissolution regimes and permeability evolution. In the forced convection or natural convection regimes, the permeability nearly remains unchanged for various Ri. However, in the mixed convection regime, permeability increase is suppressed by the gravitational effects; the underlying mechanism is that the solid phase tends to dissolve near the fracture inlet due to gravitational instability. This work improves our understanding of the gravitational effects on dissolution regimes and permeability evolution in horizontal fractures.

show abstract

“…Characterized by the Péclet number and Damköhler number, the dissolution of rough fracture at the system scale leads to different dissolution patterns. Generally, as the flow rate increases, the dissolution patterns in rough fractures shift from compact to wormhole (channeling) and further to uniform patterns (Deng, Steefel, et al., 2018; Detwiler & Rajaram, 2007; Elkhoury et al., 2013; Hu et al., 2021; Starchenko & Ladd, 2018; Szymczak & Ladd, 2009; Wang et al., 2022). For most of the core flooding experiments mentioned above, the evolution of fracture morphologies is usually quantified by the change in fracture aperture, namely the distance between the upper and lower rough surfaces (Detwiler & Rajaram, 2007; Detwiler et al., 2003; Szymczak & Ladd, 2012; Wang et al., 2022).…”

Section: Introductionmentioning

confidence: 99%

“…The geometry of channels is obtained from the selected profiles of the natural rock surfaces. Although the dissolution process of single‐crystal channels lacks the geochemical reactions and mineral heterogeneity compared to the reaction in geologic systems, the coupled effect of reaction, diffusion, and convection in channels, a core issue in fluid‐rock interaction studies, can be well represented by flow cells fabricated with single‐mineral crystal (Detwiler et al., 2003; Golfier et al., 2002; Song et al., 2014; Wang et al., 2022). Furthermore, the homogeneity of NaCl crystals facilitates our focus on the effect of surface roughness on the dissolution process.…”

Section: Introductionmentioning

confidence: 99%