CIESC Journal ›› 2024, Vol. 75 ›› Issue (5): 1987-2000.DOI: 10.11949/0438-1157.20231297

• Energy and environmental engineering • Previous Articles     Next Articles

CH4-hydrate formation and solid-phase deposition in salt-sand coexisting flow systems

Lihao LIU1(), Ting HUANG2, Yu YONG3, Xinhao LUO1, Zeming ZHAO1, Shangfei SONG1(), Bohui SHI1, Guangjin CHEN1, Jing GONG1   

  1. 1.National Engineering Research Center of Oil and Gas Pipeline Transportation Safety, Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing 102249, China
    2.Gas Hydrate and Marine Resources Strategic Research Center, CNOOC Research Institute Company Limited, Beijing 100028, China
    3.Pipe China Southwest Pipeline Company, Chengdu 610095, Sichuan, China
  • Received:2023-12-05 Revised:2024-03-28 Online:2024-06-25 Published:2024-05-25
  • Contact: Shangfei SONG

含粉砂盐水体系甲烷水合物生成与固相沉积规律

刘礼豪1(), 黄婷2, 雍宇3, 罗昕浩1, 赵泽明1, 宋尚飞1(), 史博会1, 陈光进1, 宫敬1   

  1. 1.中国石油大学(北京)机械与储运工程学院,油气管道输送安全国家工程研究中心,城市燃气输配技术 北京市重点实验室,石油工程教育部重点实验室,北京 102249
    2.中海油研究总院有限责任公司水合物和 海洋资源战略研究中心,北京 100028
    3.国家管网西南管道公司,四川 成都 610095
  • 通讯作者: 宋尚飞
  • 作者简介:刘礼豪(1997—),男,博士研究生, liuliao72@163.com
  • 基金资助:
    国家自然科学基金项目(52104069);北京市自然科学基金项目(3232030);国家重点研发计划项目(2022YFC2806200);中国博士后科学基金项目(2022M713460);中国石油大学科学基金项目(2462023BJRC018)

Abstract:

Hydrate reformation and silt deposition blockage in pipelines are key issues affecting combustible ice mining, and seawater in pipelines has a certain degree of salinity. Therefore, this study used a high-pressure loop to carry out water-silt-NaCl-CH4 system hydrate formation and hydrate-silt deposition experiments. The experiments revealed a four-stage evolution process from hydrate formation to stable solid-phase deposition. The study found that in a saline system containing sand, the induction time of hydrate formation can be significantly extended by 2-3 times compared to that in a pure water system. This extension is particularly notable under conditions of low sand concentration (0.1%(mass)) and high flow rate (1600 kg/h), reaching a maximum of 3.3 times. This is because of that the disruption of water molecule cluster structures by NaCl and sand is a crucial mechanism inhibiting hydrate nucleation. Furthermore, NaCl compresses the thickness of the particle’s double electric layer, weakening the hydrophilicity of sand particles. This, coupled with nanobubble bridging, prompts the aggregation of solid particles and their adhesion to the pipe wall, accelerating the formation of hydrate-sand deposition layers. The research findings contribute to ensuring the safety and stability of multiphase flow in the exploitation and production system for combustible ice development.

Key words: methane hydrate, induction time, deposition, flow assurance, combustible ice

摘要:

管道中水合物再生与粉砂沉积堵塞是影响可燃冰开采的关键问题,而且管道中海水具有一定矿化度。利用高压环路开展了水-粉砂-NaCl-CH4体系水合物生成与水合物-粉砂沉积实验,揭示水合物生成到稳定固相沉积的四阶段演变过程。研究发现,在含有粉砂的盐水体系中甲烷水合物的诱导期相较于纯水体系可显著延长2~3倍,特别是在低含砂浓度(质量分数0.1%)和高流量(1600 kg/h)条件下,诱导期延长至3.3倍。分析认为NaCl和粉砂对水分子簇结构的扰乱是抑制水合物成核的关键机理,此外NaCl通过压缩颗粒双电层厚度削弱砂粒亲水性,通过纳米气泡桥接促使固相颗粒聚集并黏附于管壁,加速水合物-砂沉积层的形成。研究成果有助于保障可燃冰开发排采系统中多相流动的安全与稳定。

关键词: 甲烷水合物, 诱导期, 沉积, 流动保障, 可燃冰

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