微纳米限域空间内天然气水合物动态相变规律与表征
Dynamic phase transition characteristics and representation of natural gas hydrates in micro/nano confinements
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- 引用格式:
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付强,周守为,李中,陈明强,王硕亮,徐建春.微纳米限域空间内天然气水合物动态相变规律与表征[J].天然气与石油,2024,42(6):25-34.doi:10.3969/j.issn.1006-5539.2024.06.003
FU Qiang, ZHOU Shouwei, LI Zhong, CHEN Mingqiang, WANG Shuoliang, XU Jianchun.Dynamic phase transition characteristics and representation of natural gas hydrates in micro/nano confinements[J].Natural Gas and Oil,2024,42(6):25-34.doi:10.3969/j.issn.1006-5539.2024.06.003
- DOI:
- 10.3969/j.issn.1006-5539.2024.06.003
- 作者:
- 付强1,2 周守为1,3 李中1,2 陈明强1,2 王硕亮4 徐建春5
FU Qiang1,2, ZHOU Shouwei1,3, LI Zhong1,2, CHEN Mingqiang1,2, WANG Shuoliang4, XU Jianchun5
- 作者单位:
- 1. 海洋天然气水合物全国重点实验室, 北京 100028; 2. 中海油研究总院有限责任公司, 北京 100028; 3. 中国海洋石油集团有限公司, 北京 100010; 4. 中国地质大学(北京)能源学院, 北京 100083; 5. 中国石油大学(华东)石油工程学院, 山东 青岛 266580
1. State Key Laboratory of Offshore Natural Gas Hydrate, Beijing, 100028, China; 2. CNOOC Research Institute Co. Ltd., Beijing, 100028, China; 3. China National Offshore Oil Corporation, Beijing, 100010, China; 4. College of Energy, China University of Geosciences(Beijing), Beijing, 100083, China; 5. School of Petroleum Engineering, China University of Petroleum(East China), Qingdao, Shandong, 266580, China
- 关键词:
- 微纳米孔喉;微流控实验;水合物相变动力学特征;相平衡曲线;表征模型
Micro/nano pore-throats; Microfluidic experiment; Hydrate phase transition kinetics; Phase equilibrium curve; Representation model
- 摘要:
作为中国海域天然气水合物勘探开发的重要阵地之一,琼东南海底水合物沉积层属于泥质粉砂低渗储层,具有骨架弱胶结、微纳米孔喉发育及储集空间多样等地质特征,厘清微纳米限域空间内天然气水合物动态相变规律并形成定量表征技术对沉积层水合物资源量评价及开发动态预测具有重要意义。基于琼东南水合物沉积层微观孔隙结构特征,应用最小孔径为15 nm的多尺寸微纳流控芯片技术,提出了恒压控温的微纳米限域空间内天然气水合物动态相变微观测试新方法,揭示了纳米尺寸孔喉对水合物动态生成、分解及相变规律的影响。通过对影响水合物相变规律的水活度进行分析,建立了综合考虑微纳米限域空间内毛细效应、表面吸附及可溶性盐影响的水合物相平衡定量表征新模型,为中国南海天然气水合物安全高效开发提供了一种有效的模拟方法及理论支撑，对后续开发方案定制有重要的参考意义。
As one of the key regions for natural gas hydrate exploration and development in marine sediments in China, low permeable hydrate-bearing sediments in the Qiongdongnan area are classified as clayey-silty deposits which possess complex geological properties such as weak skeletal cementation, abundant micro/nano-scale pore throats, and diverse hydrate occurrence spaces. Therefore, figuring out the dynamic phase transition characteristics of natural gas hydrates in micro/nano confined pore throats and developing quantitative representation technologies are of significance for evaluating hydrate resources and predicting the dynamic production behavior during development. In this work, multi-scale micro/nano fluidic chips were first designed and etched with a minimum pore size of 15 nm based on the microscopic pore structures of hydrate-bearing sediments in Qiongdongnan area. Afterwards, a novel microfluidics-based method for investigating the dynamic phase transition of natural gas hydrates in micro/nano confinements from a microscopic perspective was proposed. The influence of nano-scale pore throats on the dynamic formation, decomposition, and phase transition of natural gas hydrates was revealed. Through characterizing the influence of water activity on hydrate phase transition, a novel representation model for hydrate phase equilibrium considering the capillary effects, surface adsorption, and the effect of soluble salts was developed. This work provides an effective simulation method and theoretical support for the safe and efficient development of natural gas hydrates in the South China Sea, serving as an important reference for the determination of subsequent development strategies.
