新型CO2响应型耐温抗盐泡排体系的设计、作用机理和应用研究

Foam dewatering gas recovery is the most efficient and convenient auxiliary mining technology for the development of hydrous gas fields. However, there are problems such as defoaming difficulty, the emulsification and flocculation of the production fluid, and unstable foam performance under harsh working conditions. The best solution for this problem is to develop environment responsive surfactants whose foaming and defoaming ability can be artificially controlled. This project inspired by CO2-responsive function of tertiary amine-based surfactants. Firstly, CO2-responsive temperature-resistant and anti-salt surfactant molecules will be designed using molecular simulation method. The relationship between molecular structure of surfactants and their characteristics will be illustrated at the molecular level. Secondly, the target molecules will be synthesized by introducing temperature-resistant and anti-salt groups into the tertiary amine-based CO2-responsive surfactant or by aminating the head group of the temperature-resistant and anti-salt surfactants. The CO2 responsive, temperature-resistant and anti-salt foam drainage agent systems will be constructed by mixing the target surfactants and conventional anionic surfactants. Thirdly, the macroscopic properties and microscopic mechanism of CO2 response, temperature and salt resistance, condensate oil resistance, demulsifying behavior will be studied through laboratory experiments and molecular simulations. Finally, the field experiments will be performed through evaluating drainage gas recovery, defoaming and demulsification of the new foam drainage agent systems in order to obtain the complete application scheme of new developed foam drainage agent systems. The research of this project can provide technological and theoretical foundation for the development of new intelligent responsive foam drainage agents.

泡沫排水采气是开发含水气田最高效便捷的助采工艺，但现有泡排剂在使用过程中往往出现消泡困难、产出液易乳化、苛刻条件下性能不稳定等问题。开发可自由控制起泡与消泡的响应型耐温抗盐泡排剂成为解决该问题的首选。本课题以叔胺基表面活性剂的CO2响应功能为导向，首先基于分子模拟方法开展CO2响应型耐温抗盐表面活性剂的分子设计，从而在分子水平上明确新型表面活性剂分子结构与性质的关系。基于将耐温抗盐基团引入到CO2响应型表面活性剂，或将耐温抗盐表面活性剂的头基进行胺化两种思路合成目标分子，并将其与阴离子型表面活性剂进行复配以构筑新型泡排体系。通过室内实验和分子模拟手段研究泡排体系的CO2响应性、耐环境性和破乳性等宏观性能及其微观作用机制。通过现场试验研究新型泡排体系及CO2的加注制度与排水采气、消泡和破乳效果的关系，并形成完整的现场应用方案。本课题的开展能够为新型泡排剂的研发工作提供理论和技术上的依据。

泡沫排水采气是开发含水气田最高效便捷的助采工艺，但现有泡排剂在使用过程中往往出现消泡困难、产出液易乳化、苛刻条件下性能不稳定等问题。开发可自由控制起泡与消泡的响应型耐温抗盐泡排剂成为解决该问题的首选。本课题基于分子模拟手段对数量庞大的表面活性剂分子进行性能研究，获得了一系列兼有耐温抗盐功能和CO2响应性的SDS/叔胺复配泡沫体系。随后通过实验对其进一步改性合成了新型CO2响应型耐温抗盐表面活性剂9-二甲基氨基壬烷基硫酸钠（9-DUSNa）、10-二甲基氨基癸烷基硫酸钠（10-DUSNa）以及11-二甲基氨基十一烷基硫酸钠（11-DUSNa），并将合成出来的三种表面活性剂与阴离子型表面活性剂十二烷基羟基磺基甜菜碱（CHSB）进行复配，从而构筑了兼具耐温抗盐、耐凝析油和CO2响应性的泡排体系，能够实现对所生成泡沫的可控消泡和破乳。此外，通过室内实验和分子模拟手段研究发现11-DUSNa与CHSB的复配比例为2:1时具有最好的响应性能、泡沫稳定性和携液能力，并且拥有较好的耐温抗盐性能。在苏里格现场试验研究中，结合现场工况，确定了新型泡排剂加注方式、加注量和加注周期，制定了合理的泡排工作制度，对9口试验气井开发效果进行了跟踪评价。发现其中5井口对新型泡排剂有较好的适应性，其日产气量有大幅提升（2倍左右），并且能够维持稳定生产，另外4口井保持了与现役泡排剂同等的产气效果。因此本课题的开展为新型泡排剂的研发工作提供理论和技术上的依据。