P-wave velocity anisotropy related to sealed fractures reactivation tracing the structural diagenesis in carbonates

Abstract

Vp measured on a meter scale block affected by reactivated and non-reactivated fractures • Fracture reactivation decreases Vp and leads to dip anisotropy of about 10%.• It is explained by the diagenetic evolution of fracture infilling material.• Karstification is only a second-order cause, amplifying pre-existing anisotropy.

Comment on se-2021-85

“…8A-8C). Cemented subsurface fractures limit the fluid flow (Laubach et al, 2004;Matonti et al, 2017). In addition, the presence of fracture enhances dissolution, and the fracture surfaces can be observed to be enlarged by dissolution (Fig.…”

Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling

“…It probably varies from a few kilometers (e.g., Fall et al., 2015) to very shallow depths corresponding to the onset of lithification. Early embrittlement processes are common, particularly for carbonates or marly lithology (e.g., La Bruna et al., 2020), allowing fracture generation even in the first few hundreds of meters (e.g., La Bruna et al., 2020; Lavenu & Lamarche, 2018; Lavenu et al., 2013; Matonti et al., 2017). At the early (small‐depth) fracturing, σ t can be much smaller than the assumed value.…”

Comment on se-2021-85

“…show that the fractures in Bashijiqike sandstones are highly cemented, and the presences of fractures improve subsurface fluid flow (Matonti et al, 2017), and therefore the active fluids rich in Ca 2+ will be cemented along the fracture surfaces (Fig. 8A-8C).…”

“…Structural diagenesis, a cross-disciplinary approach investigating relationships between structures (deformation, fractures, etc) and diagenesis (Laubach et al, 2010), helps to better understand the changes in reservoir petrophysical properties and subsurface fluid flow (Vandeginste et al, 2012;Matonti et al, 2017;Ferraro et al, 2019;Wu et al, 2019;Rodrigues et al, 2021). Foreland fold-and-thrust belts are challenging for hydrocarbon exploration due to their structural complexity and heterogeneous reservoir quality distribution (Vandeginste et al, 2012).…”