Analysis of Interaction Between Hydraulic and Natural Fractures

The behavior of natural fractures at the hydraulic fracturing (HF) treatment is one of the most important considerations in increasing the production from this kind of reservoirs. Therefore, considering the interaction between the natural fractures and hydraulic fractures can have great impact on the analysis and design of fracturing process. Due to the existence of such natural fractures, the perturbation stress regime around the tip of hydraulic fracture leads to some deviation in the propagation of path of hydraulic fracture. Increasing the ratio of transverse stress to the interaction stress results in a reduction in the deviation of hydraulic fracturing propagation trajectory in the vicinity of natural fracture. In this study, we modeled a hydraulic fracture with the extended finite element method (XFEM) using a cohesive-zone technique. The XFEM is used to discrete the equations, allowing for the simulation of induced fracture propagation; no re-meshing of domain is required to model the interaction between hydraulic and natural fractures. XFEM results reveal that the distance and angle of natural fracture with respect to the hydraulic fracture have a direct impact on the magnitude of tensile and shear debonding. The possibility of intersection of natural fracture by the hydraulic fracture will increase with increasing the deviation angle value. At the approaching stage of hydraulic fracture to the natural fracture, hydraulic fracture tip exerts remote compressional and tensile stress on the interface of the natural fracture, which leads to the activation and separation of natural fracture walls

RETRACTED: Numerical modeling of hydraulic fracture propagation: Accounting for the effect of stresses on the interaction between hydraulic and parallel natural fractures

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of According to EGYJP committee’s decision and after precise investigation ,It is ultimately obvious that the article titled: “Numerical Modeling of Hydraulic Fracture Propagation: Accounting for the Effect of Stresses on The Interaction Between Hydraulic and Parallel Natural Fractures” by its auther Jaber Taheri Shakib is totally plagiarized from the thesis titled: “Analysis of hydraulic fracture propagation in fractured reservoirs: an improved model for the interaction between induced and natural fractures” by Arash Dahi Taleghani; http://hdl.handle.net/2152/18381; beginning from the abstract passing through chapter 3. Even the conclusion of chapter 3 is copied directly from the thesis: “Analysis of hydraulic fracture propagation in fractured reservoirs: an improved model for the interaction between induced and natural fractures” A matter which leads the committee to take its final decision of retracting the mentioned article from volume no. 22 issue 4 and blacklisting its author Dr. Jaber Taheri Shakib from our journal. Hoping that this decision is taken promptly from your honored side

4D evolutions of cracks, voids, and corrosion products in reinforced concrete materials

Abstract This research paper presents a comprehensive investigation into the corrosion process in reinforced concrete structures using advanced analytical techniques, namely non-destructive X-ray computed tomography (CT) imaging, scanning electron microscopy (SEM) images, energy dispersive x-ray spectrometry (EDS), and Raman spectroscopy. The CT image analysis allowed for the identification and quantification of pore structures, crack propagation, and corrosion progression at different stages of corrosion. CT scanning and data analysis offer valuable 4D (3D spatial + time) insights into corrosion in reinforced concrete, revealing changes in pore sizes, with smaller pores increasing and larger pores decreasing as corrosion progresses. Our investigation reveals dynamic changes in reinforced concrete pores during the accelerated corrosion test leading to new pore formation and cracking. The research identifies two distinct types of cracks: one filled with corrosion products and the other, zipper-like cracks, resulting from the connection of deformed pores without corrosion products. The SEM images and EDS analysis confirmed the absence of corrosion products within these unique zipper cracks, suggesting a different mechanism of crack formation compared to the first type of cracks. The results revealed two distinct categories of corrosion products: iron oxides and iron hydroxides, with their distribution correlated to the duration of accelerated corrosion testing. The integration and verification of results from X-ray CT imaging and Raman spectroscopy established a comprehensive understanding of corrosion-induced damage in the reinforced concrete specimen, shedding light on complex interactions among different corrosion products during the corrosion process. These findings offer crucial insights for better understanding of the corrosion process in reinforced concrete paving the way for future development of effective treatments and strategies to mitigate corrosion impact