水合物低场核磁共振弛豫响应  

Low-Field Nuclear Magnetic Resonance Relaxation Response of Hydrates

作　　者：程久辉 夏轩哲 张笑寒 王琳琳[1,2] CHENG Jiu-hui;XIA Xuan-zhe;ZHANG Xiao-han;WANG Lin-lin(College of Safety and Ocean Engineering,China University of Petroleum,Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,Beijing 102249,China;State Key Laboratory of Nature Gas Hydrate,Beijing 100028,China;CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]中国石油大学(北京)安全与海洋工程学院,北京102249 [2]油气资源与探测国家重点实验室,北京102249 [3]天然气水合物国家重点实验室,北京100028 [4]中海油研究总院有限责任公司,北京100028

出　　处：《科学技术与工程》2023年第13期5444-5450,共7页Science Technology and Engineering

基　　金：国家自然科学基金重点项目(U20B6005);国家自然科学基金重大科研仪器研制项目(22127812)。

摘　　要：水合物核磁共振表征对于海上水合物储层勘探以及地层描述具有重大意义。设计实验探究了溴化四丁基铵(TBAB)水溶液在分级降温与升温过程中的低场核磁共振弛豫响应特征。实验数据结果表明,变温过程中横向弛豫时间(T2)分布存在3个区间,即小峰区间(小于4 ms)、中峰区间(4~100 ms)和大峰区间(100~3000 ms),核磁共振弛豫信号分别来源于水合物、TBAB分子和水中的氢原子核。测试样品的温度以及T2分布演化规律能够识别样品中所包含物质,即固态水合物、TBAB水溶液、水、冰。小峰信号由水合物提供,依此建立了水合物核磁共振信号(幅值和T2)与温度的关系,可以作为量化分析水合物含量的温度校准依据。Nuclear magnetic resonance(NMR)characteristic of hydrates is of great significance for offshore hydrate reservoir exploration and stratigraphic description.The low-field NMR experiments were conducted to explore the relaxation response of tetrabutylammonium bromide(TBAB)aqueous solution during the step cooling and heating processes.The transverse relaxation time spectrum is divided into three intervals:small peak interval(<4 ms),medium peak interval(4~100 ms)and large peak interval(>100 ms),and their NMR relaxation signals originate from hydrate,TBAB molecules and water,respectively.Evolution of sample temperature and transverse relaxation time distribution can be used to distinguish the substances contained in the sample,that is,solid hydrate,TBAB aqueous solution,water,and ice.The signal of small peak interval is completely generated by TBAB hydrate,and thus the relationship between the hydrate NMR signal(amplitude and T2)and temperature is established,which can be used as a temperature calibration basis for quantitative analysis of hydrate content.

关 键 词：低场核磁共振 横向弛豫时间 幅值 TBAB水合物 变温实验 

分 类 号：P618.13[天文地球—矿床学] TE121[天文地球—地质学]