Article
Energy & Fuels
Leng Tian, Kaiqiang Zhang, Hengli Wang, Zongke Liu, Minghui Huo, Shuwen Xu
Summary: This paper develops a prediction model to analyse the complex geological characterizations and fluid properties, and track the dynamic behavior of CO2 multiphase flow in porous media. By studying the impacts of porethroat changes, diffusion-dissolution effects, and viscosity-resistance reductions on seepage resistance, a comprehensive mathematical model is developed and validated through experiments. The model can be used to predict the dynamic performance of reservoirs.
Article
Chemistry, Multidisciplinary
Lei Li, Xiaomei Zhou, Rujun Wang, Xue Zhang, Songtao Ma, Yuliang Su, Chonglin Wang, Wenting Luo, Haihang Sun
Summary: The interfacial interactions, contact angle, and oil displacement efficiency of CO2 flooding at the pore-scale were examined using microfluidics, with a focus on the effects of temperature, pressure, and surfactants. The results demonstrated that increasing pressure and adding surfactants promoted oil-gas contact and reduced interfacial tension, leading to higher oil recovery. Curved channels hindered CO2-oil contact, while non-ionic alkoxylated surfactants enhanced CO2-oil interaction and increased oil recovery through increased solubility and reduced interfacial tension.
JOURNAL OF CO2 UTILIZATION
(2023)
Article
Energy & Fuels
Hui Gao, Kaiqing Luo, Yonggang Xie, Yin Qi, Teng Li, Zhilin Cheng, Chen Wang
Summary: In this study, the influence of the microscopic pore structure on CO2 flooding characteristics in tight sandstone reservoirs was investigated. Two types of sandstone visualization models were used in experiments, and the results showed that the model with more favorable pore structure had a higher oil recovery efficiency. Additionally, increasing the injection pressure and volume improved the oil recovery rate.
Article
Energy & Fuels
Wenzhe Yang, Yunsheng Chang, Jindian Cheng, Zhiguo Wang, Xingbo Li, Pengfei Lv, Baoliang Zhang, Lei Wang, Bin Liu, Yongchen Song
Summary: This study investigates the permeability and heterogeneity in CO2-EOR processes using magnetic resonance imaging, revealing that heterogeneity has a significant impact on parameters like mixing zone length and velocity during miscible displacement, indicating that heterogeneity is more important than permeability in determining flow characteristics. The Lattice-Boltzmann method is also employed for local pore-space simulation, showing stable fronts in local space and suggesting that more attention should be focused on heterogeneity rather than permeability for future research.
Article
Chemistry, Multidisciplinary
Jing Li, Chuanzhi Cui, Zhongwei Wu, Jiqing Yi, Ran Zong, Yihui Fu, Xingyuan Han
Summary: CO2 miscible flooding in low permeability reservoirs improves oil recovery significantly. The existing microscopic displacement simulation mainly focuses on the seepage process, with a lack of pressure control and characterization of CO2 concentration diffusion. To address these issues, a numerical model is established to analyze the interphase mass transfer in CO2 miscible flooding at the pore scale. The injection velocity, contact angle, diffusion coefficient, and initial injection concentration are analyzed to understand their effects on seepage characteristics and concentration distribution. The study shows that CO2 preferentially diffuses into the large pore space, forming a miscible area with crude oil through mass transfer. The increase in injection velocity accelerates the seepage process and increases the sweep area. Higher contact angles increase the resistance and decrease the recovery efficiency. Increasing the diffusion coefficient results in higher CO2 concentration in small pores. Higher initial injection concentration leads to higher CO2 concentration in large pores and miscible areas. This study provides guidance to further understand the microscopic seepage characteristics of CO2 miscible flooding with interphase mass transfer.
Article
Energy & Fuels
Mingyu Cai, Yuliang Su, Yongmao Hao, Yingchun Guo, Derek Elsworth, Lei Li, Dongsheng Li, Xinyu Li
Summary: Dynamic monitoring of CO2 flooding using online low-field NMR imaging revealed that recovery by miscible flooding was significantly higher than immiscible flooding, primarily due to remnant dissolved CO2 in the miscible zone. CO2 concentrations at the leading edge of the miscible zone were higher than in the immediately adjacent transition zone, and the CO2 retention rate following miscible flooding was also notably higher compared to immiscible flooding.
Article
Chemistry, Multidisciplinary
Jing Li, Chuanzhi Cui, Zhongwei Wu, Jiqing Yi, Ran Zong, Yihui Fu, Xingyuan Han
Summary: CO2 miscible flooding in low permeability reservoirs can significantly improve oil recovery. Current research mainly focuses on the simulation of seepage process in CO2 miscible flooding, while lacking pressure control and characterization of CO2 concentration diffusion. In this study, a numerical model of CO2 miscible flooding is established and the microscopic seepage characteristics of interphase mass transfer are analyzed. The effects of injection velocity, contact angle, diffusion coefficient, and initial injection concentration on the seepage characteristics and concentration distribution of CO2 miscible flooding are investigated. The results show that CO2 preferentially diffuses into the large pore space and forms a miscible area with crude oil through interphase mass transfer. The increase in injection velocity accelerates the seepage process and expands the sweep area. The increase in contact angle increases the seepage resistance and decreases the recovery efficiency. The increase in diffusion coefficient leads to higher CO2 concentration in small pores. The larger the initial injection concentration, the higher the CO2 concentration in the large pore and miscible areas. This study provides guidance for understanding the microscopic seepage characteristics of CO2 miscible flooding.
Article
Geochemistry & Geophysics
Anlun Wang, Xiaoqing Zhao, Jianguang Wei, Lisha Zhao, Guangliang An, Xiaofeng Zhou, Jiangtao Li, Xuedong Shi, Ying Yang, Gen Li
Summary: Miscible CO2 flooding is an effective method for oil recovery, but the heterogeneity at the pore level can significantly affect its efficiency. This study proposes a method based on NMR T-2 spectrum to determine the distribution of residual oil in sandstone without the need for additional agents. The results show that the residual oil is mainly distributed in small pore throats, and the heterogeneity of pore size affects the displacement efficiency. There are also unswept areas with residual oil that can be targeted for further improvement.
Article
Construction & Building Technology
Bin Zhuo, Ruyue Zhang, Yong Fang, Yubo Wang, Yuxiang Yao
Summary: This paper investigates the improvement mechanism of anionic surfactant on clay minerals through molecular dynamics simulation and laboratory experiments, and evaluates the conditioning effect of the surfactant at the macroscopic scale by testing zeta potential and stirring torque of the clay minerals under different foam injection ratios.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Agricultural Engineering
Minmin Qiu, Yanmei Meng, Yizhe Li, Xiaobin Shen
Summary: This study investigated the influences of internal and external factors on the cut quality of sugarcane stalks. The optimal combination of cutting system parameters was identified through numerical simulations and experimental validation, resulting in improved quality of cut in cutting tests. Additionally, the study also explored the damage mechanisms of sugarcane arising from internal factors, providing valuable information for the design of a base cutter for sugarcane harvesting.
BIOSYSTEMS ENGINEERING
(2021)
Article
Environmental Sciences
Danyan Chen, Hao Liu, Yunwang Ning, Cong Xu, Hui Zhang, Xinyu Lu, Jidong Wang, Xianju Xu, Yuanyuan Feng, Yongchun Zhang
Summary: Unreasonable water and inorganic nitrogen fertilization can intensify soil greenhouse gas emissions. The matching of water and nitrogen fertilization factors can regulate soil greenhouse gas efflux. This study investigated the effects of water and nitrogen fertilization patterns on soil greenhouse gas efflux and found that reduced nitrogen fertilization contributes to the effective mitigation of soil nitrous oxide and carbon dioxide efflux by lowering the soil total nitrogen and organic carbon contents and regulating soil microbial biomass carbon and nitrogen. The W1N60 pattern was identified as the preferred pattern with high environmental impact.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Chemistry, Multidisciplinary
Xinliang Chen, Hongwei Yu, An Cao, Zhengming Yang, Wen Li, Zhongkun Niu, Yilin Chang, Meng Du
Summary: This study investigates the mechanism by which oil recovery can be enhanced through different CO2 injection methods in miscible flooding to mitigate the influence of heterogeneous reservoirs. A double-layer long core was designed and prepared for four CO2 displacement experiments with different injection methods. By analyzing the injection-production parameters, the displacement effects of different injection methods were compared, and the mechanism of enhanced oil recovery (EOR) was summarized. The results indicate that the displacement efficiency of the different injection methods follows the order of alternate CO2-water injection, continuous CO2 flooding, cyclic CO2 flooding, and alternate CO2-hydrocarbon gas injection. The recovery of crude oil via CO2 miscible flooding in heterogeneous reservoirs relies on convective diffusion and miscible mass transfer, and it is necessary to choose an injection method that optimizes both aspects to improve the recovery efficiency.
Article
Energy & Fuels
Yiwei Sun, Liang Wang, Ruixue Wang, Siwen Zheng, Xiaoxue Liao, Zibin Zhu, Yuchen Zhao
Summary: By conducting research on the microscopic mechanisms of CH4 and CO2 adsorption in different rank coals, this study provides data and theoretical basis for the development of CO2-enhanced coal bed methane recovery (CO2-ECBM) technique. The results show that micropores are the main sites for adsorption in coal, and changes in chemical functional groups directly affect the adsorption capacity of coal by affecting micropore evolution. In addition, CO2 molecule has a stronger adsorption energy and closer distance to the coal molecule compared to CH4 molecule.
Article
Geochemistry & Geophysics
Lanlan Yao, Qihong Lei, Zhengming Yang, Youan He, Haibo Li, Guoxi Zhao, Zigang Zheng, Haitao Hou, Meng Du
Summary: This study conducted a physical simulation experiment of surfactants + CO2 (SPC) to analyze the influence of surfactant on the CO2 displacement effect of interlayer shale oil reservoir. The results showed that the use of surfactant can significantly improve the displacement efficiency and relative displacement content of the reservoir, especially in the case of small pores and ultralow permeability.
Article
Energy & Fuels
Xiangji Dou, Pengfei Zhu, Guodong Qi, Yanfeng He, Dongdong Shao, Kun Qian
Summary: This study investigates the microscopic displacement mechanism of shale oil by CO2 in organic nanopores using simulations and models. The results show that the displacement of alkane and the adsorption of CO2 are influenced by the injection pressure of CO2 and the pore size. Additionally, the study reveals the existence of an optimum temperature for CO2 adsorption, with the adsorption capacity increasing and then decreasing with temperature.
Article
Energy & Fuels
Zihao Li, Wei Zhang, Yongqiang Tang, Baiguang Li, Zhaojie Song, Jirui Hou
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2016)
Article
Energy & Fuels
Yongqiang Tang, Chengyuan Lv, Rui Wang, Maolei Cui
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2016)
Article
Energy & Fuels
Tang Yongqiang, Hou Jirui, Li Chenghui
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2013)
Article
Energy & Fuels
Yongqiang Tang, Rui Wang, Zihao Li, Maolei Cui, Zengmin Lun, Yu Lu
Article
Chemistry, Multidisciplinary
Yongqiang Tang, Zihao Li, Rui Wang, Maolei Cui, Xin Wang, Zengmin Lun, Yu Lu
Article
Energy & Fuels
Xueli Liu, Yongqiang Tang, Ting Xu
Summary: Crestal CO2 injection is an effective method to control water coning in a strong bottom water reservoir. The mechanism involves shifting the water phase downward and reducing the oil viscosity, thus preventing water breakthrough and improving the efficiency of water flooding for oil displacement.
PETROLEUM SCIENCE AND TECHNOLOGY
(2023)