NMR Relaxation Response of CO2 Hydrate Formation and Dissociation in Sand

被引：11

作者：

Chen He-Long ^{[1
,2
]}

Wei Chang-Fu ^{[1
]}

Tian Hui-Hui ^{[1
]}

Wei Hou-Zhen ^{[1
]}

机构：

[1] Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

来源：

ACTA PHYSICO-CHIMICA SINICA | 2017年 / 33卷 / 08期

基金：

中国国家自然科学基金;

关键词：

Nuclear magnetic resonance; Hydrate saturation; Hydration number; Hydrate distribution; Relaxation behavior; POROUS-MEDIA; METHANE; SOLUBILITY; STABILITY; SEDIMENTS;

D O I：

10.3866/PKU.WHXB201704194

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Quantification and characterization of hydrate formation and dissociation in sediments are highly important in the study of the physical properties of hydrate-bearing sediments. In this paper, the behavior of CO2 hydrate formation and dissociation in sand is studied using the nuclear magnetic resonance (NMR) technique. The components of the pore space, including gas, liquid water, and hydrate, were quantified using a convenient method by which the hydration number was determined. No abrupt change in the relaxation behavior of the sample was found during hydrate formation and dissociation. In addition, the value of mean-log T-2 appeared to be proportional to the liquid water content of the sample with or without the pore hydrate. A straightforward explanation is that the liquid water in the pore space remains in contact with grain surfaces, and relaxation occurs mainly at the grain surface. The results suggest that, rather than coating the grains, the hydrate is pore-filling or cementing.

引用

页码：1599 / 1604

页数：6

共 24 条

[11] Deep sea NMR: Methane hydrate growth habit in porous media and its relationship to hydraulic permeability, deposit accumulation, and submarine slope stability [J].