Article
Energy & Fuels
Ziming Wang, Qilin Wang, Zhiqiang Fan, Wei Wei, Mengxin Li, Yanfeng Wang, Xuehua Huang, Yongchen Song, Dayong Wang
Summary: This paper summarizes classical and popular permeability models associated with hydrate dissociation and demonstrates an equivalency and replaceability relationship between different permeability models through systematic numerical sensitivity analysis, providing a basis for simplifying the selection of permeability models.
Article
Engineering, Marine
Mingtao Chen, Yanlong Li, Penghui Zhang, Guigang Yu, Zhun Zhang, Yajuan Zhang, Haiyang Jiang, Bin Gong, Nengyou Wu
Summary: This study investigates the deformation mechanisms of hydrate-bearing sediments with laminar hydrate distribution through numerical simulations. The results indicate that the hydrate saturation and thickness ratio significantly affect the mechanical behavior of the sediments.
Article
Energy & Fuels
Yongmao Hao, Fan Yang, Jian Wang, Mingwu Fan, Shuxia Li, Shiwei Yang, Chuanming Wang, Xinhai Xiao
Summary: This paper investigates the impact of multilateral well exploitation technique on natural gas hydrates, utilizing simulation to study the mechanisms and changes in temperature, pressure, and hydrate concentration during gas production. Results show that the multilateral well technique significantly enhances the production capacity of hydrates.
Article
Thermodynamics
Bao-Can Dong, Peng Xiao, Yi-Fei Sun, Jing-Yu Kan, Ming-Ke Yang, Xiao-Wan Peng, Chang-Yu Sun, Guang-Jin Chen
Summary: This study analyzed the evolution and geological stability of hydrate deposits in the South China Sea during depressurization using a numerical model. The analysis also determined the gas-water production. The findings provide important insights for the exploitation of marine heterogeneous hydrates.
Article
Energy & Fuels
Jiaqi Wang, Jiale He, Xin Lv, Kun Ge, Chuanxiao Cheng, Hongsheng Dong
Summary: This study optimized a 2-D simulator to model the evolution of temperature, pressure, hydrate saturation, and gas production behavior in hydrate sediments during the decomposition process via stepwise depressurization. The analysis showed that the specific heat capacity, thermal conductivity, and gas relative permeability are the main factors affecting hydrate decomposition.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Marine
Xuyang Guo, Yan Jin, Jingyu Zi, Jiaying Lin, Bolong Zhu, Qian Wen, Qi Jing
Summary: Sand production is a significant challenge in the exploitation of methane hydrates, affecting gas productivity. This study presents a numerical model that describes the coupled thermal-hydraulic-mechanical-chemical responses and sand production patterns during horizontal well depressurization in methane-hydrate-bearing sediments. The results show the spatial and temporal evolution patterns of multi-physical fields and highlight the sensitivity of gas and sand production rates to various parameters.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Thermodynamics
Yongchang Feng, Lin Chen, Yuki Kanda, Anna Suzuki, Atsuki Komiya, Shigenao Maruyama
Summary: Artificial fractures in methane hydrate reservoirs can significantly improve hydrate dissociation and gas production efficiency, particularly in the early depressurization stage. Higher fracture permeability may shorten the economical production stage but lead to higher production rates. Furthermore, fractures facilitate the flow of hot water into the sediment, enhancing production efficiency during the economical production stage.
Article
Engineering, Chemical
Jiayuan He
Summary: The results of the second trial production in the South China Sea show that the use of horizontal wells greatly increases the daily gas production of gas hydrate reservoirs. However, the current production is still below the commercial development requirement. A fishbone well with multiple branches shows potential for higher productivity in depressurization development, but there is a lack of research on its application in Class I gas hydrate reservoirs.
Article
Chemistry, Multidisciplinary
Taehun Lee, Joo Yong Lee, Taewoong Ahn, Han Am Son
Summary: The cyclic depressurization method can significantly enhance geomechanical stability and increase gas production. It was found that by utilizing different bottomhole pressure and production time during depressurization, cumulative gas production can be greatly improved, while maintaining or even increasing stability in the subsurface.
APPLIED SCIENCES-BASEL
(2021)
Article
Thermodynamics
Panpan Zhang, Shouceng Tian, Yiqun Zhang, Gensheng Li, Wenhong Zhang, Waleed Ali Khan, Luyao Ma
Summary: This study innovatively proposes the use of radial jet drilling technology to stimulate oceanic hydrate reservoirs, and investigates the combined effects of radial wells and depressurization on gas production efficiency from gas hydrate-bearing sediments. Results show that radial wells can significantly enhance gas production rate but cannot extend the gas production life cycle. Additionally, the study characterizes the stimulation mechanisms of radial wells induced by depressurization.
Article
Engineering, Chemical
Yuanfang Cheng, Mingyu Xue, Jihui Shi, Yang Li, Chuanliang Yan, Zhongying Han, Junchao Yang
Summary: This study established a fully coupled THMC model to quantitatively assess the vertical displacement of the formation induced by hydrate decomposition and identify the influence laws of various factors on wellhead stability. The results showed that the decomposition of hydrate weakens the mechanical properties of the formation, leading to wellhead subsidence. Factors such as thickness of hydrate formation, initial hydrate saturation, overburden depth of hydrate sediment, and mudline temperature significantly affect wellhead stability, while the effect of mudline temperature can be neglected.
Article
Energy & Fuels
Peixiao Mao, Jiaxin Sun, Fulong Ning, Lin Chen, Yizhao Wan, Gaowei Hu, Nengyou Wu
Summary: The study demonstrates that in inclined hydrate reservoirs, placing a single horizontal production well in the structural low can increase gas and water production; production performance in upper sandy reservoir and middle muddy reservoir are sensitive to the layout of production wells.
Article
Energy & Fuels
Qingping Li, Shuxia Li, Shuyue Ding, Zhenyuan Yin, Lu Liu, Shuaijun Li
Summary: In this study, a THMC numerical model was developed to simulate the gas productivity and reservoir stability of natural gas hydrate reservoirs. The simulation results showed that CO2 exchange promotes the dissociation of NGH and increases the production of gas and water while reducing reservoir subsidence.
Article
Geosciences, Multidisciplinary
Shang Shilong, Gu Lijuan, Lu Hailong
Summary: The study of industrial exploitation of natural gas hydrate has progressed with production tests in permafrost and offshore regions, indicating that depressurization and multi-well production can improve gas production efficiency.
ACTA GEOLOGICA SINICA-ENGLISH EDITION
(2021)
Article
Geochemistry & Geophysics
Wang WenBo, Liu Xiao, Cui Wei, Xiao JiaQi
Summary: The study established a mathematical model of gas hydrate reservoir and solved it using finite difference method to investigate the decompression process. The results showed that during depressurization, a pressure drop funnel forms around the wellbore, leading to decomposition of hydrate near the wellbore, decrease in hydrate saturation, and increase in permeability. The decomposition transition zone moves outward and its width gradually stabilizes with production time, while the main control parameters include production well pressure, initial hydrate saturation, absolute permeability, and hydrate decomposition kinetic constants.
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
(2021)