海洋地质与第四纪地质2024，Vol.44Issue(6)：71-81,11.DOI:10.16562/j.cnki.0256-1492.2024090901
盐度影响下松散沉积物中甲烷水合物生成特征研究
Effect of salinity on the formation of methane hydrate in unconsolidated sediments
摘要
Abstract
In-depth understanding of the characteristics of methane hydrate formation in unconsolidated sediments containing saline solution is of great significance for the accurate evaluation of hydrate resources in marine sediments.In this study,the effect of salinity on the formation characteristics of methane hydrate in unconsolidated sand samples was studied using the low-field nuclear magnetic resonance in-situ detection technology.Results show that there were differences in the induction time of hydrate formation in pores of different sizes in the unconsolidated sands;methane hydrate was more likely to form in small pores.As the salinity of pore water increased,the induction time of hydrate formation increased exponentially.In the first 20 minutes,the hydrate formation rate first increased and then decreased,and the formation rate was the highest under the salinity of 3.0 wt%.At different locations of the unconsolidated sediments,the difference in the induction time of methane hydrate formation and the mode change of water through the hydrate film caused changes in the hydrate formation rate.The large potential energy on sediment surface and the barrier effect caused by the presence of hydrates prevented some pore water in the samples from being converted into hydrates.The increase in the initial salinity of pore water could enhance the barrier effect,decrease the final conversion rate of pore water,and reduce the hydrate saturation.关键词
水合物生成/松散沉积物/低场核磁共振/盐度Key words
hydrate formation/unconsolidated sediment/low-field nuclear magnetic resonance(LF-NMR)/salinity分类
海洋科学引用本文复制引用
纪云开,王佳贤,邱晓倩,孟庆国,张永超,胡高伟,蔡峰,刘昌岭..盐度影响下松散沉积物中甲烷水合物生成特征研究[J].海洋地质与第四纪地质,2024,44(6):71-81,11.基金项目
国家自然科学基金"南海北部高富集天然气水合物储层特征与成藏控制机理研究"(U2244224),"南海神狐海域水合物储层气-水-水合物三相共存微观机理研究"(42206233),"海洋沉积物中水合物生成过程的孔隙水转化规律及其控制机理研究"(42176212) （U2244224）
泰山学者工程项目(tsqn202312280) （tsqn202312280）
