摘要
基于水合物勘探与开发现场井筒内气体流动情况,模拟井筒内水合物的形成过程,在恒温、恒压和恒泡状流条件下评价几种常见氨基酸对水合物形成各阶段的抑制情况及聚集形态的影响,并探究其抑制水合物形成的内在机理。研究结果表明:随着疏水性增强,氨基酸抑制效果变差,抑制效果较好的氨基酸最终在井筒内形成的水合物壳更薄、更大,水合物形成总量更少;在水合物形成过程中,井筒出口流量发生2次阶梯形突降,水合物形成速率曲线随时间呈典型的“驼峰”状;对于同一种氨基酸,在相同浓度时,对各阶段抑制效果由高到低依次为Ⅲ阶段(停止进气)、Ⅱ阶段(水合物正常形成)和Ⅰ阶段(水合物诱导期);氨基酸抑制机理随着水合物生成阶段不同而变化,在水合物生长初期主要表现为—NH2及—COOH对水分子的吸附及扰乱作用,在水合物形成中后期,氨基酸分子被形成的水合物排开,氨基酸膜包裹在水合物晶体周围,从而阻止水合物成核及晶体进一步生长。
Based on gas flow in wellbore of hydrate exploration and development site,formation process of hydrate in wellbore was simulated.Under the condition of constant temperature,constant pressure and constant bubble flow,the effects of several common amino acids on the inhibition of hydrate formation at various stages and aggregation morphology were evaluated and internal mechanism of inhibition of hydrate formation was explored.The results show that the inhibition effect of amino acids becomes worse with the increase of hydrophobicity.The amino acids with better inhibition effect eventually form a thinner and larger hydrate shell,and the total amount of hydrate formation is less.In the process of hydrate formation in wellbore,there are always two precipitous drops in outlet flow rate and the curve of hydrate formation rate with time shows a typical"hump"shape.For the same amino acid,at the same concentration,the inhibition effect on each stage from high to low is stage III(stop intake),stage II(normal formation of hydrate)and stage I(hydrate induction period).The inhibition mechanism of amino acids changes with different hydrate formation stages.At the early stage of hydrate growth,the adsorption and disturbance of water molecules by—NH2and—COOH are the main factors.In the middle and later periods of hydrate formation,amino acids are pushed out by hydrate formation to form amino acid film surrounding hydrate crystal,thus hydrate nucleation and crystal further growth are prevented.
作者
刘志辉
罗强
张贺恩
宁伏龙
刘志超
郭东东
欧文佳
LIU Zhihui;LUO Qiang;ZHANG Heen;NING Fulong;LIU Zhichao;GUO Dongdong;OU Wenjia(School of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;CNPC Offshore Engineering Company Limited,Beijing 100028,China;National Center for International Research on Deep Earth Drilling and Resource Development,Ministry of Science and Technology,Wuhan 430074,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第3期799-809,共11页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(41672367
51704266)
广东省海洋经济发展(海洋六大产业)专项资金资助项目(粤自然资合[2020]047号)
青岛海洋科学与技术国家实验室2016年度开放基金资助项目(QNLM2016ORP0203)。
关键词
水合物
动力学抑制剂
氨基酸
动态评价
聚集形态
hydrate
kinetic inhibitors
amino acid
dynamic evaluation
aggregation morphology
