Investigation of Stress Field and Fracture Development During Shale Maturation Using Analog Rock Systems

Development of 3‐D Curved Fracture Swarms in Shale Rock Driven by Rapid Fluid Pressure Buildup: Insights From Numerical Modeling

“…The emergence of complex fracture swarms stems from fracture interactions and the perturbed stress field. Extant literature attributes the formation of complex fracture networks during the shale maturation process to several factors, including rock properties (Vega et al, 2020), stress anisotropy (Chauve et al, 2020;Rabbel et al, 2020;Teixeira et al, 2017), flaw density and distribution (Paluszny et al, 2020;Teixeira et al, 2017), and heating rate (Panahi et al, 2018). We would like to elucidate the evolution of the fracture swarms under quasi-static growth from the perspective of mechanical interaction behaviors between neighboring fractures.…”

“…To the best of the authors' knowledge, few if any numerical studies have yet been performed to simulate the development of nonplanar 3-D fracture swarms, except for several attempts in investigating the evolution of 2-D planar/nonplanar fracture networks (Z. Fan et al, 2014;Jin et al, 2010;Rabbel et al, 2020;Vega et al, 2020). Previous numerical and experimental studies have recognized that development of the fracture networks will experience the following three stages: (1) individual growth; (2) interaction and coalescence; and (3) loss of fluid overpressure and fracture aperture (Kobchenko et al, 2011;Rabbel et al, 2020).…”

“…Previous numerical and experimental studies have recognized that development of the fracture networks will experience the following three stages: (1) individual growth; (2) interaction and coalescence; and (3) loss of fluid overpressure and fracture aperture (Kobchenko et al, 2011;Rabbel et al, 2020). Although 2-D models are useful for quantifying the onset, propagation, coalescence, and evolution of fluid-driven fracture networks (Vega et al, 2020) and the 2-D results are easy to comprehend and visualize (Rabbel et al, 2020), absence of the third dimension would lead to a potential knowledge gap that may impede a better understanding of realistic patterns of interacting fracture swarms.…”

Fractal Characterization of Multimodal, Multiscale Images of Shale Rock Fracture Networks

“…A collection of multidimensional, multimodal, and multiscale shale core sample and rock analog images with sample sizes ranging from microns to meters and resolution ranging from nanometers to microns was sourced from published [37][38][39] and our unpublished data. A visual summary of the data included in this study, sorted according to Euclidean (vertical axis) and length (horizontal axis) dimensions is shown in Figure 1.…”

“…Grayscale microscopy (G series): Scanning Electron Microscope (SEM) mosaics images and X-ray nano-and micro-tomography reconstructions of samples from the Green River formation were sourced from [37,40]. High-resolution photography (A series): These are images of rock analog materials at the meso-scale (lab-grade gelatin), acquired with a highresolution DSLR camera in a setup and process described in [38]. Tabular and graphic (W series): Macro-scale fracture networks were generated from tabular fracture data reported on the Wolfcamp site in the Midland, TX Formation core samples described in [20], and illustrations of microfluidics designs (M series) at the micro-scale were sourced from [39].…”