Article
Energy & Fuels
Morteza Esfandiari, Ali Pak
Summary: This study evaluates the effects of in-situ stress on hydraulic fracture characteristics using the XFEM method. The accuracy of the analytical formulas of KGD and PKN models is examined by conducting numerical simulations. The results show that the analytical formulas differ from the numerical simulations due to simplifying assumptions and neglecting certain parameters. Correction factors are proposed to improve the results of KGD and PKN models. The findings of this study can contribute to more accurate design of hydraulic fracture processes in the oil industry for increased hydrocarbon reservoir production.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2023)
Review
Energy & Fuels
Hai T. Nguyen, Jang Hyun Lee, Khaled A. Elraies
Summary: The pseudo-three-dimensional (P3D) approach serves as an efficient computational tool in hydraulic fracture modeling, bridging the gap between two-dimensional and three-dimensional models. The evolution of P3D modeling and its application in complex fracture network models for shale oil and gas reservoirs has been discussed, with simulations showing good validation of the numerical algorithm and the impact of variable injection rates on fracture propagation.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Energy & Fuels
Yiwen Gong, Ilham El-Monier, Mohamed Mehana
Summary: The study used a coupled Eulerian-Lagrangian approach to quantify proppant distributions in complex fracture networks and validated the method's effectiveness. It was found that networks with secondary and tertiary fractures tend to receive more proppant, and the impact of fracturing fluid viscosity on proppant transport varies.
Article
Geochemistry & Geophysics
Keita Yoshioka, Masafumi Katou, Kohei Tamura, Yutaro Arima, Yoshiharu Ito, Youqing Chen, Tsuyoshi Ishida
Summary: Hydraulic fractures often interact with preexisting discontinuities in the rock mass, and the criteria for fracture penetration or deflection are typically based on the in situ stress and the characteristics of the discontinuities. However, experiments on carbonate rocks show that fractures more frequently deflect at grain boundaries as they propagate farther from the wellbore, which is not explained by the conventional criteria. Our study demonstrates that the energy dissipation of a deflecting fracture increases with the distance from the wellbore, making it energetically more favorable for a fracture to deflect at a discontinuity. This highlights the importance of energetic stability analysis for determining fracture paths.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Geological
Xiaoxuan Li, Hannes Hofmann, Keita Yoshioka, Yongjiang Luo, Yunpei Liang
Summary: Hydraulic fracturing is a widely used technique in unconventional reservoirs. The interactions between hydraulic fracture and natural fracture can have a significant impact on the fracture patterns and subsequent productivity. In this study, a phase-field model is used to investigate the influence of in-situ stress, fracturing operational parameters, and natural fracture orientation and strength on the fracture propagation path. The results provide insights into the mechanism behind different propagation patterns and factors affecting fracture complexity.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Petroleum
Hai Qu, Yang Xu, Jun Hong, Xiangjun Chen, Chengying Li, Xu Liu
Summary: Understanding proppant transport and distribution in hydraulic fractures is crucial to designing and optimizing hydraulic fracturing treatments in the field. However, many rough models are too small to accurately display proppant transport behaviors. This study proposed a novel method to develop large-scale rough panels reproduced from actual hydraulic fractures.
Article
Geochemistry & Geophysics
Yuxin Chen, Yunhong Ding, Chong Liang, Dawei Zhu, Yu Bai, Chunmei Zou
Summary: Radial drilling-fracturing technology combines hydraulic fracturing and radial boreholes to efficiently develop low permeability reservoirs. A model of two radial boreholes is established to predict fracture initiation pressure (FIP) and interference between radial boreholes. Sensitivity analysis shows that FIP decreases with more radial boreholes, smaller intersection angle and depth difference.
Article
Geochemistry & Geophysics
Aleksei Titov, Gary Binder, Youfang Liu, Ge Jin, James Simmons, Ali Tura, David Monk, Grant Byerley, Mike Yates
Summary: The study focuses on optimizing well spacings and completions in unconventional reservoir development, using VSP survey data acquired in 2017 with fiber-optic-based distributed acoustic sensing technology. Scattered seismic waves associated with hydraulic fractures were observed, with the LVZ model showing the best fit for the data. A new approach was developed to estimate SRV characteristics and HF closure time, providing cost-effective real-time monitoring of hydraulic fracturing operations and critical constraints on unconventional field development.
Article
Engineering, Geological
Seyed Erfan Saberhosseini, Zhongwei Chen, Mohammad Sarmadivaleh
Summary: The study investigates the initiation and propagation of multiple hydraulic fractures using XFEM-CZM model and CPNM method to achieve minimal deviation and create deeper and wider fractures between two horizontal wells. The results show that increasing flow rate is preferred for creating smooth and deeper multiple hydraulic fractures in zipper fracturing, but injection time should be optimized.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2021)
Article
Mathematics
Kairui Li, Nickolay N. Smirnov, Chengzhi Qi, Mingyang Wang, Dmitry A. Pestov, Anastasia A. Shamina
Summary: This paper investigates the effect of rock's fracture toughness heterogeneity on hydraulic fracture propagation. A planar-3D model is developed to analyze the evolution of hydraulic fracture propagation and the stage before fracture propagation using a typical heterogeneous distribution of rock's fracture toughness. Numerical comparison experiments are conducted to study the effect of rock's toughness heterogeneity. The results indicate that the sizes and locations of maximum fracture openings are determined by the minimum fracture radius and the contrast of rock's fracture toughness between adjacent layers. The fracture contour is greatly influenced by the heterogeneity of rock's fracture toughness.
Article
Engineering, Multidisciplinary
Mingqi Qin, Diansen Yang, Weizhong Chen
Summary: Researchers established a 3D hydraulic fracturing model based on peridynamics and validated it against an analytical solution. The results showed significant differences between the 3D and 2D models, as the 3D model accounted for fracture propagation in the height direction.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2022)
Article
Engineering, Civil
Gang Lei, Qinzhuo Liao, Shirish Patil
Summary: This work establishes a reasonable model to determine the essential controls on the conductivity of hydraulic fractures under stress conditions, showing conductivity curves characterized by six stages and emphasizing the importance of proppant compaction in conductivity changes.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Civil
Chen He, Chi Yao, Qinghui Jiang, Chuangbing Zhou
Summary: This study proposes a semi-analytical method for estimating the anisotropic hydraulic conductivity of fractured rock masses based on the discrete fracture network (DFN) description and Snow's model. It extends the initial Snow's model from infinite connectivity conditions to finite connectivity conditions by constructing correction coefficients to adjust the contribution of each individual fracture to the macro hydraulic conductivity tensor. The correction coefficients are determined using a mathematical optimization method under isotropic orientation and polydisperse size distribution conditions. The method is applied successfully to predict the directional hydraulic conductivity of engineering rock masses with complex anisotropic oriented fracture networks.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Geological
Amirhossein Kamali, Ahmad Ghassemi, Dharmendra Kumar
Summary: An advanced numerical model is developed to investigate stimulation in naturally-fractured rocks. The model reveals that hydraulic fractures experience pressure drop upon intersection with natural fractures and may propagate in other directions. Simultaneous interaction with multiple natural fractures and/or stress barriers results in complex hydraulic fracture geometries.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Zeeshan Tariq, Bicheng Yan, Shuyu Sun, Manojkumar Gudala, Murtada Saleh Aljawad, Mobeen Murtaza, Mohamed Mahmoud
Summary: In this study, machine learning models were efficiently utilized to predict the breakdown pressure of unconventional rocks. A comprehensive hydraulic fracturing experimental study was conducted on various rock specimens, and the rock mechanical properties and experimental conditions were correlated using machine learning techniques. The accuracy of all machine learning models was similar, with an accuracy of 95% in predicting the breakdown pressure. The proposed methodology can minimize experimental costs and be used as a quick assessment tool for evaluating the development prospect of unconventional tight rocks.
Article
Mechanics
Yue Gao, Emmanuel Detournay
Summary: Experimental evidence shows that the measured toughness increases with confining stress. However, interpreting the observed breakdown pressure relies on assuming uniform fluid pressure in the cracks and identifying the peak pressure with fracture initiation pressure. The model challenges these assumptions by considering fluid lag and hydraulic compliance, indicating that the actual toughness may be overestimated when the breakdown pressure is used to interpret it.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Mechanics
Zhi-Qiao Wang, Emmanuel Detournay
Summary: This paper investigates the motion of a liquid blister trapped between an elastic sheet and a rigid substrate, driven by a frictionless blade. The study aims to evaluate the force applied by the blade on the moving blister, with solutions depending on two controlling numbers. The results show that for small gaps, the force is dominated by viscous dissipation, while for larger gaps, the force depends on both toughness and gap size.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Geological
Emmanuel Detournay, Yera Hakobyan
Summary: The paper presents a KGD-type model for hydraulic fracture in weak, poorly consolidated rocks, with a key assumption that the hydraulic fields are quasi-stationary. The model shows the growth of fracture as a square root of time and the transition between early and late time asymptotic flow regimes.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Engineering, Multidisciplinary
Zhi-Qiao Wang, Emmanuel Detournay
Summary: This paper investigates the dynamics of a liquid blister forced to advance between a thin elastic sheet and a rigid substrate by the dual action of a piston and a flat frictionless sleeve. The study focuses on the dependence of external driving force on blister velocity, fluid viscosity, elastic properties of the sheet, and interface toughness, with a particular emphasis on the Eshelbian nature of the horizontal driving force. The numerical and asymptotic solutions predict the scaled horizontal force on the moving liquid blister and highlight the importance of three key numbers in controlling the solution.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2022)
Article
Engineering, Geological
Arviandy G. Aribowo, Roeland Wildemans, Emmanuel Detournay, Nathan Van de wouw
Summary: This paper extends the drag (PDC) bit interface laws for homogeneous rocks to the transition between two rock layers with distinct mechanical properties. A model is formulated to establish the relationships between the weight-on-bit, torque-on-bit, depth-of-cut per bit revolution, and engagement parameter of the bit in the lower rock layer. The paper shows that the drilling efficiency depends nonlinearly on the bit engagement between the two rock layers.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Mechanics
Yue Gao, Emmanuel Detournay
Summary: This paper describes a two-dimensional model of a hydraulic fracture propagating in a weakly consolidated, highly permeable reservoir rock during a waterflooding operation. The model highlights essential differences from conventional hydraulic fracturing treatments of oil and gas wells and reveals the non-monotonic evolution of injection pressure over time. Poroelasticity significantly affects the response of the system, increasing injection pressure and delaying the time at which the peak pressure occurs.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Energy & Fuels
Kaixiao Tian, Emmanuel Detournay
Summary: This paper extends the class of models simulating self-excited vibrations in a rotary drilling system by considering different types of PDC bits, and proposes algorithms to address technical challenges. Linear stability analysis is based on geometric variations of the bit/rock engagement surfaces to determine critical rotation speeds for different stability regions.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Robotics
Gillian J. McDonald, Emmanuel Detournay, Timothy M. Kowalewski
Summary: A reliable estimate for bending stiffness is crucial for predicting various aspects of soft robot performance. Current methods rely on accurate material knowledge, and measuring actuator stiffness can be costly and complex.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Engineering, Manufacturing
Kaidong Chen, He Zhang, Nathan van de Wouw, Emmanuel Detournay
Summary: This paper introduces a method for describing the milled surface using a surface function and accurately computing the instantaneous undeformed chip thickness (IUCT). The method overcomes the inaccuracies of traditional models and shows promise for computing the IUCT in milling processes.
JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Mathematics, Applied
He Zhang, Emmanuel Detournay
Summary: This paper analyzes the self-excited axial and torsional vibrations of rotary drilling systems using a complex mathematical model that combines the drilling structure with a rate-independent bit-rock interface law. By utilizing an algorithm to convert the system of PDE-ODEs into a system of coupled ODEs and linearizing the system for stability analysis, the paper concludes that the effects of damping on the stability of drilling system is generally negligible in the range of practical drilling parameters. Extensive parametric studies have shown that bit wearflats play a crucial role in delaying or suppressing torsional stick-slip oscillations.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2022)
Article
Mechanics
He Zhang, Jia-Liang Le, Emmanuel Detournay
Summary: This paper reports the results of scratch tests on three different rocks, showing the existence of three cutting regimes with different fragment shapes and specific energy-depth relationships. It also provides evidence from video recording and fractography to distinguish different failure modes.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mechanics
Anthony Peirce, Emmanuel Detournay
Summary: The deflation dynamics of a fluid-driven fracture in a permeable elastic medium are investigated in this study. The research findings show that the deflation of the fracture is influenced by the leak-off characteristics of the porous medium and the stress intensity factor of the fracture. A numerical scheme is established to explore the deflation dynamics of plane strain hydraulic fractures, and scaling analysis reveals the existence of asymptotic power law behaviors for various quantities.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Mechanics
Anthony Peirce, Emmanuel Detournay
Summary: This paper discusses the construction of tip asymptotes for a hydraulic fracture in a permeable elastic medium. It describes the changing nature of the asymptotic fields during the arrest and recession phases of the fracture after fluid injection has ended. The paper shows that as the fracture deflates, the dominance of the linear elastic fracture mechanics tip asymptote shrinks, giving way to an intermediate asymptote. The front velocity affects the development of a linear asymptote at the fracture tip, with the intermediate asymptote reappearing. These universal multiscale asymptotes are crucial for determining the decaying stress intensity factor, transition from arrest to recession, and front velocity during recession using computational algorithms.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Geological
Jithin S. Kumar, Abhijit Chaudhuri, Emmanuel Detournay, Ramesh Kannan Kandasami
Summary: In this study, a model is proposed to analyze the deformation around a cylindrical cavity caused by fluid injection. The study investigates the solution in different phases and introduces a time-dependent permeation coefficient and four time-dependent variables to solve the problem. A parametric analysis of the influence of material stiffness and strength on the solution is conducted.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Mechanics
Anthony Peirce, Emmanuel Detournay
Summary: This paper explores approximate 'sunset' similarity solutions for receding hydraulic fractures in permeable elastic media. It shows that the linear aperture of a receding hydraulic fracture has a linear asymptote and can be described by polynomial solutions. The paper also demonstrates that the sunset solution forms an attractor for a wide range of hydraulic fractures as they approach closure. Furthermore, the paper finds that the sunset solution is dependent on only one material parameter, the leak-off coefficient, which can be determined through laboratory or field measurements.
JOURNAL OF FLUID MECHANICS
(2022)