Article
Microbiology
Maria Fernanda Campa, Jeremy R. Chen See, Lavinia Unverdorben, Olivia G. Wright, Kimberly A. Roth, Jonathan M. Niles, Daniel Ressler, Ella M. S. Macatugal, Andrew D. Putt, Stephen M. Techtmann, Timothy L. Righetti, Terry C. Hazen, Regina Lamendella
Summary: The environmental implications of unconventional oil and gas extraction are only recently starting to be systematically recorded. Our research shows the utility of microbial communities paired with geochemical markers to build strong predictive random forest models of unconventional oil and gas activity and the identification of key biomarkers.
MICROBIOLOGY SPECTRUM
(2022)
Article
Energy & Fuels
Yijin Zeng, Yintong Guo, Xu Zhang, Qiqi Ying, Xin Chang
Summary: The mechanical properties and fracture propagation characteristics of inter-salt shale reservoirs in the Qianjiang sag are studied. The results show clear differences between different rhythms. This research provides insights into the mechanism of hydraulic fracture propagation in inter-salt shale formations.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2023)
Article
Engineering, Petroleum
A. S. Gundogar, J. L. Druhan, C. M. Ross, A. D. Jew, J. R. Bargar, A. R. Kovscek
Summary: Field and laboratory observations show that the efficiency of hydraulic fracturing is affected by geochemical alterations to rock surfaces, which can block pore and fracture networks. The study focuses on changes to fluid chemistry and shale surfaces resulting from shale-fluid interactions. Different shale samples have different responses to fluid injection, indicating the importance of understanding the specific characteristics of the formation.
Article
Energy & Fuels
Jihuan Wu, Xuguang Li, Yu Wang
Summary: Laboratory tests were conducted to examine the effects of natural fracture density (NFD) on hydraulic fracture propagation and interaction with natural fractures. The experiments showed that dense fracture networks lead to strong interaction and fluctuation in pump pressure, while sparse networks result in sudden drops. Different propagation behaviors were observed in fractured model blocks. The study confirmed the relationship between NFD and fracturing effectiveness using a proposed index, and found the formation of mixed fracture types. These findings are beneficial for understanding the influence of NFD on hydraulic fracture propagation and developing accurate simulation models for unconventional oil and gas development.
Article
Energy & Fuels
Yushi Zou, Shicheng Zhang, Xinfang Ma, Xiaohuan Zhang, Shipeng Zhang
Summary: This study finds that continental shale oil formations are more complex and heterogeneous than marine shale formations. The presence of dense laminas, lithologic interfaces, and mineral-filled natural fractures in these formations can create complex hydraulic fracture growth, proppant placement, and conductivity evolution mechanisms. The findings provide important insights for the implementation of hydraulic fracturing.
Article
Engineering, Geological
Wei Zhou, Guoxin Shi, Jianbo Wang, Jiantong Liu, Ning Xu, Pengyu Liu
Summary: In this study, a double torsion experiment was conducted to simulate the propagation of tensile fractures during hydraulic fracturing. The influence of bedding planes on fracture toughness, morphology, and propagation rate in shale and tight sandstone was investigated. The results indicate that the angle between bedding and pre-cut plane, as well as the difference in micromechanical properties of adjacent bedding planes, are crucial in determining whether hydraulic fractures can penetrate or spread along a bedding plane.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Hai Qu, Shimao Tang, Ying Liu, Pengpeng Huang, Xiaoguang Wu, Zhonghua Liu, Chengying Li
Summary: The study shows that using liquid nitrogen (LN2) for shale fracturing can decrease the breakdown pressure, activate pre-existing fractures and bedding planes, and enhance formation permeability. Lower stress anisotropy, higher pumping rate, and lower bedding plane angle result in more complex fractures.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Energy & Fuels
Temoor Muther, Fahad Iqbal Syed, Amirmasoud Kalantari Dahaghi, Shahin Negahban
Summary: Gas adsorption onto the shale system is crucial for forecasting gas production and estimating reserves accurately. This study investigates the impact of different gas adsorption characteristics on reservoir production responses in Marcellus shale for different fractured well configurations. The analysis shows that gas desorption can improve overall gas production by up to 5% in a single-stage multi-clustered fractured horizontal well, with a more significant effect observed during longer flow periods and in areas with high surface area and large fracture networks.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Polymer Science
Guodong Zou, Bin Pan, Weiyao Zhu, Yuwei Liu, Shou Ma, Mingming Liu
Summary: Fracturing fluids are widely used in hydraulic fracturing of shale gas reservoirs, but the efficiency of fluid flowback is often less than 50%, which limits shale gas recovery. This study conducted microscopic experiments to simulate the flowback process of fracturing fluids in shale gas reservoirs and analyzed the mechanisms and factors affecting flowback/retention. The results showed that flowback efficiency is positively correlated with fluid concentration and gas driving pressure difference. The study also identified four mechanisms responsible for fluid retention and observed that flowback efficiency increases with higher capillary number. These findings contribute to the understanding of fracturing fluid flowback in shale gas reservoirs and provide guidance for reservoir development.
Article
Engineering, Geological
Jun Wang, Heping Xie, Cunbao Li
Summary: The laboratory hydraulic fracturing tests on Longmaxi shale samples from southwest China revealed significant brittle failure characteristics and anisotropic phenomena, with main failure patterns identified as split, split-bending, and slip along the bedding plane. Anomalously high breakdown pressure was observed in the samples at different layer orientations, which led to the development of a new tensile stress-based model for interpreting such unusual pressures. This study may have practical implications for field hydraulic fracturing operations.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Bo Zhang, Zhanqing Qu, Tiankui Guo, Ming Chen, Jiwei Wang, Yuanhang Zhang
Summary: A thermo-hydro-mechanical-damage (THMD) coupling model was constructed to investigate the effects of reservoir temperature, convective heat transfer coefficient, in-situ stress difference, and bedding plane angle on shale hydraulic fracturing. The results show that multiple hydraulic fractures can occur under thermal shock, and their complexity is influenced by reservoir temperature, in-situ stress difference, and bedding plane angle.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2023)
Article
Energy & Fuels
Xiaolong Ma, Dandan Jiang, Youhong Sun, Shengli Li
Summary: This study experimentally investigated the hydraulic fracturing behavior of clayey silt NGH reservoir and found the importance of even ice distribution on fracture propagation, as well as the influence of injection rate on complex fracture formation.
Article
Mechanics
Feipeng Wu, Xianzhang Fan, De Li, Hongbin Yang, Jing Liu, Xiaojun Li
Summary: The main technology for removing deep plugging in unconsolidated sandstone reservoirs is deep penetrating hydraulic fracturing with chemical treatment. The study analyzed the effects of different viscosities and injection rates on fracture initiation and propagation, finding that high viscosity fracturing fluid at high injection rates can achieve hydraulic fracturing in high-permeability unconsolidated sandstone, and adjusting the viscosity and injection rate slightly higher than the threshold value can generate deep penetrating fractures in unconsolidated sandstones.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Geological
Yide Guo, Xibing Li, Linqi Huang
Summary: This study investigates the impact of spontaneous water imbibition on the dynamic tensile strength of shale discs. The results show that water imbibition weakens the tensile strength, except for discs with a bedding orientation of 90 degrees. The coupling effects of bedding orientation and loading rate on tensile strength are also examined. The rate-dependent failure mode is observed in discs with bedding orientations of 30 degrees, 45 degrees, and 60 degrees, and this phenomenon is exacerbated after water imbibition.
ENGINEERING GEOLOGY
(2022)
Article
Energy & Fuels
Lianghao Zhai, Yang Xun, Huanan Liu, Bo Qi, Jinghua Wu, Yafei Wang, Chen Chen
Summary: Perforation hydraulic fracturing plays a crucial role in developing unconventional oil and gas resources. This study scaled critical parameters and simulated field-scale operations using a true triaxial hydraulic fracturing experimental system. The research investigated the influence of various perforation and fracturing fluid parameters on fracture propagation behavior and network morphology. The findings provide insights into fracture propagation and network morphology prediction in oil shale exploitation.
Article
Engineering, Multidisciplinary
Jihoon Kim
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2018)
Article
Engineering, Multidisciplinary
Jihoon Kim
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2018)
Article
Engineering, Multidisciplinary
Hyun C. Yoon, Jihoon Kim
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2018)
Article
Energy & Fuels
Jihoon Kim, Evan Schankee Um, George J. Moridis
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2018)
Article
Geochemistry & Geophysics
Evan Schankee Um, Jihoon Kim, Michael J. Wilt, Michael Commer, Seung-Sep Kim
Article
Computer Science, Interdisciplinary Applications
Maria Vasilyeva, Eric T. Chung, Yalchin Efendiev, Jihoon Kim
JOURNAL OF COMPUTATIONAL PHYSICS
(2019)
Article
Engineering, Geological
Hyun C. Yoon, Xuyang Guo, Jihoon Kim, John Killough
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2019)
Article
Computer Science, Interdisciplinary Applications
Hyun C. Yoon, Peng Zhou, Jihoon Kim
JOURNAL OF COMPUTATIONAL PHYSICS
(2020)
Article
Geochemistry & Geophysics
Evan Schankee Um, Jihoon Kim, Michael Wilt
Article
Engineering, Geological
Sangcheol Yoon, Jihoon Kim, Evan Schankee Um
Summary: This study investigates the effects of coupled multiphase flow and geomechanics in hydraulically fractured reservoirs using numerical simulations. A new numerically stable sequential method for all-way coupled geomechanics and flow in discrete fractured systems is proposed. The study identifies vacuum areas and dry zones at the fracture tip, with the vacuum area being attributed to different time scales between flow and geomechanics.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Hyun C. Yoon, Jihoon Kim
Summary: In this study, two operator splitting methods, two-pass and spectral deferred correction (SDC), are investigated for high-order accuracy in time integration for poroelastic problems. The research shows that SDC in conjunction with the monolithic method can achieve the desired second-order accuracy, while when combined with the two sequential methods, it only maintains first order.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Engineering, Geological
Jihoon Kim, Joo Yong Lee, Tae Woong Ahn, Hyun Chul Yoon, Jaehyung Lee, Sangcheol Yoon, George J. Moridis
Summary: In this study, we validate a coupled flow-geomechanics simulator called T+M-AM for gas hydrate deposits. Two laboratory experiments are conducted to replicate the production of gas hydrates by depressurization in the Ulleung Basin. The results show that T+M-AM is a reliable simulator for strongly coupled flow and geomechanics systems in both permafrost and deep oceanic hydrate deposits.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Energy & Fuels
Hyun Chul Yoon, Sangcheol Yoon, Joo Yong Lee, Jihoon Kim
Summary: The study investigates depressurization strategies for gas hydrate reservoirs using a multiple porosity model, finding that a periodic depressurization scenario exhibits less subsidence compared to continuous depressurization, while maintaining similar productivity.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2021)
Article
Energy & Fuels
Hyun Chul Yoon, Jihoon Kim, Evan Schankee Um, Joo Yong Lee
Summary: This study investigates the feasibility of using electromagnetic geophysics methods to detect gas hydrate dissociation in the Ulleung Basin, East Sea, Korea. Flow and geomechanics simulations were performed and the electrical conductivity model for electromagnetic simulation was established based on the obtained saturation and porosity fields. Two different approaches in the electromagnetic configuration were compared, and it was found that the surface-to-borehole method showed improved sensitivity in monitoring gas flow. This integrated simulation can be a potential tool for monitoring gas hydrate deposits.
Article
Engineering, Chemical
George J. Moridis, Jihoon Kim, Matthew T. Reagan, Se-Joon Kim
Summary: This study investigates the feasibility of long-term production from a marine hydrate accumulation in the Ulleung Basin in the Korean East Sea. The analysis shows that production from this hydrate accumulation is technically possible, although gas production rates are generally low and there is a high water-to-gas ratio. Additionally, there are uncertainties in the predictions of the geomechanical system's behavior. The long-term production potential of the reservoir appears challenging due to limited dissociation effectiveness, significant water production, and substantial subsidence.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)