Article
Thermodynamics
Jing Li, Yetong Xie, Huimin Liu, Xuecai Zhang, Chuanhua Li, Lisong Zhang
Summary: This research analyzed the real-time evolution of shale permeability using a combination of micro and macro experiments. The study examined the influence of osmotic pressure, pore pressure, and confining pressure on permeability evolution and studied the mechanism of the slippage effect on permeability using microscopic observations. The results showed that permeability decreased with an increase in osmotic pressure, increased with an increase in pore pressure, and decreased with an increase in confining pressure. The study also established a regression function to quantitatively describe the permeability evolution under the combined effect of confining pressure and pore pressure.
Article
Mechanics
Gang Lei, Jiangtao Qu, Qi Wu, Jiangtao Pang, Dongyu Su, Jinan Guan, Chunhua Lu
Summary: A theoretical model for the threshold pressure of gas-water two-phase flow through tight porous media is proposed based on fractal theory. The model takes into account the effects of effective stress, pore structures, gas-water capillary pressure, and boundary layer. The model is validated by comparing the predicted threshold pressure with experimental results. Furthermore, the effects of parameters such as gas-water surface tension, contact angle, initial porosity, and elastic modulus on the threshold pressure are studied.
Article
Geology
Mohammad Derafshi, Ali Kadkhodaie, Hossain Rahimpour-Bonab, Rahim Kadkhodaie-Ilkhchi, Hamid Moslman-Nejad, Amir Ahmadi
Summary: Detecting and understanding pore types and geometries in porous media is essential for mapping reservoir properties. This study used velocity deviation logs and capillary pressure curves to estimate pore system properties of the Fahliyan Formation. Petrographic studies and velocity log calculations identified different pore types and their distribution in the reservoir. The results indicate that diagenesis plays a significant role in developing complex pore types and determining reservoir quality.
CARBONATES AND EVAPORITES
(2023)
Article
Energy & Fuels
S. Alessa, A. Sakhaee-Pour, F. N. Sadooni, H. A. Al-Kuwari
Summary: This study quantifies the control of pore-scale features on transport properties by investigating the Midra shale in Qatar. The research reveals a narrow distribution of pore-throat size with an average of approximately 22 nm, and a wide distribution of pore-body size with an average of 18 nm, which suggests modifications are needed in the representation of subsurface conditions for transport properties dependent on pore-throat size.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Energy & Fuels
Peng-Fei Zhang, Shuang-Fang Lu, Jun-Qian Li, Xiang-Chun Chang, Jun-Jian Zhang, Yu-Mao Pang, Zi-Zhi Lin, Guo Chen, Ya-Jie Yin, Yu-Qi Liu
Summary: This study investigates the pore connectivity and controlling factors of shale oil reservoirs using spontaneous imbibition (SI) combined with nuclear magnetic resonance (NMR) technologies. The findings reveal that shale has poor connectivity primarily controlled by inorganic minerals, while organic matter negatively influences connectivity.
Article
Energy & Fuels
Bo Liu, Reza Nakhaei-Kohani, Longhui Bai, Zhigang Wen, Yifei Gao, Weichao Tian, Liang Yang, Kouqi Liu, Abdolhossein Hemmati-Sarapardeh, Mehdi Ostadhassan
Summary: By analyzing the pore structure of unconventional shale reservoirs, this study used intelligent smart models to estimate the volumes of nitrogen adsorption and desorption. The results showed that the LSSVM model had the highest predictive accuracy, and clay minerals and potash feldspar had the greatest effect on the amount of nitrogen adsorbed and desorbed.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Chong Cao, Linsong Cheng, Xiangyang Zhang, Junjie Shi
Summary: In this paper, a new evaluation model for unconsolidated sanding wells is proposed, considering the impact of sanding and pressure on permeability, and evaluating production performance through numerical calculations. It was found that by considering key parameters such as stress sensitivity and sanding zone size, a theoretical basis for adjusting development plans for horizontal wells can be provided for petroleum engineers.
Article
Materials Science, Multidisciplinary
Fuyong Wang, Yun Zai
Summary: This paper characterizes the pore structure of shales using high-pressure mercury intrusion (HPMI) test, fractal theory, and multifractal theory, revealing that fractal dimension can be a key index for evaluating the complexity of shale nanopores. Additionally, the multifractal parameters provide insights into the size, concentration, and asymmetry of pore size distribution in shale nanopores.
RESULTS IN PHYSICS
(2021)
Article
Environmental Sciences
Feng Yang, Bin Lyu, Shang Xu
Summary: This study investigated water uptake and drainage in shales and proposed a method to evaluate shale permeability using dynamic water sorption. The apparent diffusion coefficients of water sorption on shales were determined, showing different trends with water saturation levels. Liquid water was found to contribute more than 80% to water transport in shales, with water vapor mainly playing a role in shales with low water saturation. The study suggests that water sorption kinetics can be used as an indirect method to assess water transport properties when direct measurements are not available.
WATER RESOURCES RESEARCH
(2021)
Article
Energy & Fuels
Lanlan Yao, Qihong Lei, Zhengming Yang, Youan He, Haibo Li, Guoxi Zhao, Zigang Zheng, Haitao Hou, Meng Du, Liangbing Cheng
Summary: The physical property changes caused by stress changes in the process of volumetric fracturing of shale oil have an impact on the recovery. This research conducted a physical simulation experiment with constant confining pressure and variable pore pressure using an online nuclear magnetic resonance (NMR) technique. The results showed that increasing pore pressure was more effective for matrix reservoirs, while unloading pressure had less influence on fractured reservoirs. Increasing pore pressure greatly supplemented formation energy and improved the permeability of matrix reservoirs.
Article
Energy & Fuels
Debin Xia, Zhengming Yang, Tiening Gao, Haibo Li, Wei Lin
Summary: This study used high-precision high-pressure mercury intrusion experimental techniques and fractal theory to analyze the micro-nano-pore structure characteristics and heterogeneity of shale oil reservoirs. The research found that the micro-nano-pores in the shale oil reservoir are concentrated and continuous, distributed in the range of 30-500 nm, with a larger fractal dimension indicating stronger heterogeneity.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2021)
Article
Geochemistry & Geophysics
Zhenkai Wu, Jie Zhang, Xizhe Li, Hanmin Xiao, Xuewei Liu, Yuan Rao, Yang Li, Yongcheng Luo, Longfei Ma
Summary: This study established an experimental method for studying stress sensitivity during reservoir depletion mining and water injection development, and investigated the influence of different degrees of microcrack development on stress sensitivity. The results showed that axial compression loading acts as preloading stress and realizes the stress sensitivity process under certain conditions.
Article
Energy & Fuels
Yongchao Wang, Yanqing Xia, Zihui Feng, Hongmei Shao, Junli Qiu, Suping Ma, Jiaqiang Zhang, Haoyuan Jiang, Jiyong Li, Bo Gao, Lingling Li
Summary: Pore network modeling based on digital rock is used to evaluate the mobility of shale oil, showing that the increase in organic matter content affects the permeability of oil-water phases in shale formations.
Article
Mechanics
Tao Zhang, Liehui Zhang, Yulong Zhao, Ruihan Zhang, Dongxu Zhang, Xiao He, Feng Ge, Jianfa Wu, Farzam Javadpour
Summary: This study investigates the gas-water transient imbibition and drainage processes in two-dimensional nanoporous media using a lattice Boltzmann model. Sensitivity analyses were performed on fluid and rock characteristics, revealing the fingering nature of the nonwetting phase. The study provides insights into the microscopic ganglia dynamics of gas-water two-phase flow in nanoporous media.
Article
Engineering, Marine
Yujie Li, Zhen Guo, Lizhong Wang, Hongkuan Yang
Summary: A coupled bio-chemo-hydro-wave model for microbially induced calcite precipitation (MICP) in seabed reinforcement is proposed in this paper. The model can capture bacterial behavior, evolution of chemical substances, and changes in porosity and permeability. Results indicate that the distribution of bacteria and chemical substances is heterogeneous and related to injection rate and time. Calcium carbonate content, porosity, and permeability are significantly affected by initial bacterial concentration, injection rate, time, and cementing solution concentration. Although MICP increases vertical pore pressure gradient in shallow seabed, the seabed remains stable under large waves due to increased soil weight and cohesive force.
