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

Abstract

An array of multimodal and multiscale images of fractured shale rock samples and analogs was collected with the aim of improving the numerical representation of fracture networks. 2D and 3D reconstructions of fractures and matrices span from 10−6 to 100 m. The origin of the fracture networks ranged from natural to thermal maturation to hydraulically induced maturation. Images were segmented to improve fracture identification. Then, the fractal dimension and length distribution of the fracture networks were calculated for each image dataset. The resulting network connectivity and scaling associations are discussed at length on the basis of scale, sample and order of magnitude. Fracture network origin plays an important role in the resulting fracture systems and their scaling. Rock analogs are also evaluated using these descriptive tools and are found to be faithful depictions of maturation-induced fracture networks.

An Improved Crack Identification Method for Asphalt Concrete Pavement

“…To further verify the ability of this method in identifying the distribution direction of cracks, we tested the time consumption of this method in identifying images when the number of images is large. In order to make the experimental results more satisfactory, the methods of reference [5], reference [6], reference [7], reference [8] and reference [9] were used to carry out the experiment. The experimental results are shown in Figure 5.…”

“…However, this method is affected by the selection of parameters of the principal component analysis algorithm, resulting in a poor application effect. Vega et al proposed a fractal feature identification method for multimode and multiscale images of fracture networks [9]. This method collects a group of multimode and multiscale images of fracture samples and analogues, and calculates the fractal dimension and length distribution of fracture networks for each image data set.…”

Influence of Horizontal Multi-Bedding on Hydraulic Fracture Propagation in Shale Reservoirs

“…1 Small homogeneous non-bedding specimens of 200 mm × 200 mm × 200 mm in size are fabricated using the matrix material and cured at room temperature for 7 days (Figure 2a). 2 The small test piece is cut into 10 mm and 20 mm sheets. Holes are punched in the middle of the sheets for subsequent placement of the stainless-steel simulation sleeve (Figure 2b).…”

“…Due to the low permeability of shale reservoirs, hydraulic fracturing technology is vital for increasing economic productivity. Oil and gas export mainly depends on the artificial fracturing system [1,2]. As layered sedimentary rock, shale displays an obvious bedding structure, with relatively developed micro-fractures in some layers.…”

Impact of fracture properties on the performance of engineered geothermal systems in the crystalline basement of Kuujjuaq (Canadian Shield)

“…Despite the scale effect is not a scienti c novelty nowadays, with many publications highlighting the need for a multiscale fracture network characterization (e.g., Hardebol et al, 2015;Espejel et al, 2020;Bossennec et al, 2021Bossennec et al, , 2022Chabani et al, 2021a, b;Ceccato et al, 2022;Frey et al, 2022;Vega and Kovscek, 2022), it is still an important issue to address when developing stochastic discrete fracture network (DFN) models for heat-ow simulations. Predicting EGS performance requires a stochastic DFN model that is illustrative of the natural fracture network observed, and multiscale datasets are helpful to obtain more representative fracture data.…”