Anti-Agglomerants Performance in Hydrates Management: Fundamental Insights

水合物管理中的抗凝聚剂性能：基本见解

• 批准号: EP/N007123/1
• 负责人: Alberto Striolo
• 金额: $ 43.84万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN007123%2F1
• 关键词: Anti; Agglomerants; Performance; Hydrates; Management

Gas hydrates represent both a possible energy source in the form of methane gas, and could provide a strategy for long-term CO2 repository. Gas hydrates are also a nuisance during the transport of oil and gas via pipelines, where their formation can block and sometimes break the pipeline, causing large environmental damages. The industry, including BP and E-ON, invests ~$500 million per year injecting methanol in pipelines. Unfortunately, methanol, to be effective, needs to be present in amounts exceeding 20% by weight, sometimes up to 50% of the transported fluid.As the productive oil wells become more and more removed from onshore refining facilities, and as productive oil wells age, leading to increased amount of water produced, new strategies are desperately needed. The present project focuses on alternative chemicals that should be effective (1) at low weight fraction to reduce the amount of fluids transported and pumped through the pipelines; (2) at low temperature and for long time, to be effective through the entire length of the pipelines needed to reach the wells far from shore; and (3) in systems that contain large amounts of water, to allow the exploitation of ageing wells, which produce large amounts of water together with oil and gas.These chemicals, considered in this project, are known as anti agglomerants (AAs), and they can be effective at concentrations as low as 5% by volume. BASF, Schlumberger, Shell, Champion and Halliburton manufacture and formulate anti-agglomerants. Although it is believed that AAs allow small hydrate particles to form, and then prevent their agglomeration into large plugs, their mechanism of action is not well understood. Consequently, their discovery is based on lengthy trial-and-error protocols conducted on systems representative of the fluids extracted from given oil and gas wells.To enable the systematic discovery of new effective AAs, the fundamental research proposed here focuses on their molecular mechanism of action. Molecular modelling and massive computer simulations will be implemented, in synergism with detailed micro- and macro-scopic experiments, for a specific class of anti-agglomerants. These compounds contain three hydrophobic tails, and one extended hydrate-philic head that comprises both carboxylic and quaternary ammonium ions. These molecules have been chosen because macroscopic experimental observations show that by changing the length of one of the hydrophobic tails by just 2-6 carbon atoms, while maintaining the rest of the molecule intact, changes their performance from excellent to poor. Our hypothesis is that the molecular structure of a film of AAs formed on a hydrate particle affects the growth mechanism. Two possible mechanisms have been identified by preliminary simulations: (1) aggregation of hydrates, and (2) penetration of water through the AAs film. It is possible that one of the two mechanisms acts as the dominant one at different experimental conditions (e.g., varying salt concentration). The proposed research is designed to first understand and quantify the molecular mechanisms of action of the AAs under various experimental conditions, and then to understand which AAs molecular features can be tuned to maximise their performance.The fundamental results expected are relevant not only for better understanding hydrates management, but also for better understanding the molecular mechanisms involved in all crystallisation processes. Such processes occur in a number of industries (e.g., pharmaceuticals, specialty chemicals, coatings, foodstuff) that represent the backbone of UK high tech manufacturing. The sectors that will be positively impacted by the proposed research include energy, manufacturing, chemicals and environment.

天然气水合物既是甲烷气体的一种可能的能源来源，也可能为长期的二氧化碳储存库提供一种策略。在石油和天然气通过管道运输的过程中，天然气水合物也是一种滋扰，它们的形成可能会阻塞管道，有时还会破坏管道，造成巨大的环境破坏。包括BP和E-On在内的行业每年在管道中注入甲醇的投资约为5亿美元。不幸的是，要发挥作用，甲醇的含量需要超过20%的重量，有时高达输送液体的50%。随着生产油井越来越多地远离陆上炼油设施，随着生产油井老化，导致产水量增加，迫切需要新的策略。本项目的重点是应有效的替代化学品：(1)在低重量分数下，以减少通过管道输送和泵送的流体的数量；(2)在低温和长时间下，在到达远离海岸的油井所需的整个管道长度上有效；以及(3)在含有大量水的系统中，允许开采老化油井，这些老油井与石油和天然气一起产生大量的水。在本项目中考虑的这些化学品被称为防凝聚剂(AAs)，它们可以在体积浓度低至5%的情况下有效。巴斯夫、斯伦贝谢、壳牌、冠军和哈里伯顿制造和配制防结块剂。虽然人们相信AAs允许形成小的水合物颗粒，然后防止它们凝聚成大的堵塞，但它们的作用机制还不是很清楚。因此，他们的发现是基于对代表从给定油气井中提取的流体的系统进行漫长的反复试验的协议。为了能够系统地发现新的有效的AA，这里提出的基础研究集中在它们的分子作用机制上。分子建模和大规模计算机模拟将与详细的微观和宏观实验协同实施，用于特定类别的防结块剂。这些化合物包含三个疏水尾巴和一个延伸的亲水化合物头部，包括羧基和季铵离子。之所以选择这些分子，是因为宏观实验观察表明，通过仅将其中一个疏水尾巴的长度改变2-6个碳原子，同时保持分子的其余部分不变，它们的性能就会从优秀变为较差。我们的假设是，在水合物颗粒上形成的AAs膜的分子结构影响生长机制。通过初步模拟，确定了两种可能的机理：(1)水合物的聚集；(2)水通过AAS膜的渗透。在不同的实验条件下(例如，不同的盐浓度)，这两种机制中的一种可能起主导作用。这项拟议的研究旨在首先了解和量化AAs在各种实验条件下的分子作用机制，然后了解哪些AAs的分子特征可以被调节以使其性能最大化。预期的基本结果不仅与更好地理解水合物管理有关，而且对于更好地理解所有结晶过程中涉及的分子机制也是相关的。这些过程发生在许多行业(例如，制药、特种化学品、涂料、食品)，这些行业代表着英国高科技制造业的支柱。将受到拟议研究的积极影响的行业包括能源、制造业、化学品和环境。

项目成果

Directly probing surfactant adsorption on nanoscopic trenches and pillars.

• DOI: 10.1016/j.jcis.2020.06.020
• 发表时间: 2020-06
• 期刊: Journal of colloid and interface science
• 影响因子: 9.9
• 作者: J. J. Hamon-J.;R. Tabor;A. Striolo;B. Grady

Atomic Force Microscopy Force Mapping Analysis of an Adsorbed Surfactant above and below the Critical Micelle Concentration.

• DOI: 10.1021/acs.langmuir.8b00574
• 发表时间: 2018-05
• 期刊: Langmuir : the ACS journal of surfaces and colloids
• 作者: J. J. Hamon-J.;R. Tabor;A. Striolo;B. Grady

Structure-Function Relation in Anti-Agglomerants

抗凝聚剂的结构-功能关系

• 发表时间: 2017
• 作者: Bui, T.

Anti-Agglomerants Performance: Insight from Molecular Simulations

抗凝聚剂性能：分子模拟的见解

• 发表时间: 2018
• 作者: Bui T.

Evidence of Structure-Performance Relation for Surfactants used as Anti-Agglomerants for Hydrates Management

用作水合物管理抗凝聚剂的表面活性剂的结构-性能关系的证据

• 发表时间: 2017
• 作者: 164. T. Bui