Abstract: This paper is focused on problems existing in dehydration process of inferior crude oil that is rich in oxygen, sulfur and other impurities. Element Si is introduced into the main chain of traditional demulsifier to improve the surface activity of demulsifier and eliminate the effect of stability that non-hydrocarbon compounds, such oxygen and sulfur, have on emulsified liquid. The emulsion will lose its stability by the effects of replacement while emulsion is formed in a structure of pectination by introducing a mass of branch chains, thus increasing steric hindrance of its film-forming and ensuring free movement of dispersive water drops. The characteristics of macromolecules improve demulsifier’s capacity to catch micro drops and its further dehydration effects. Based on the study of synergistic effect, the appropriate accessory ingredient is selected to compound with other demulsifier. As a result, the high-efficiency macromolecular crude demulsifier of D series is developed to solve the dehydration problems of high acidic and high sulfur crude oil, fulfilling the objective for further dehydration by lowering water cut of crude oil to less than 0.2 percent after dehydration. Demulsifiers of this series have been widely used in Africa’s oilfields, solving actual problems in production process and keeping oilfields in normal production.

Key words: demulsifier, high sulfur crude, high acidic crude, macromolecule, emulsion, dehydration

摘要： 针对富含氧、硫等杂元素的特殊类、劣质采出油脱水过程中存在的问题,利用在破乳剂主链中引入Si元素的方法,提高破乳剂的表面活性,消除含氧、硫等杂原子的非烃化合物对乳状液的稳定作用。通过顶替原理使乳状液失稳并引入大量的支链而形成“梳状”结构,提高了破乳剂自身成膜的位阻,保证分散水滴的自由移动;大相对分子质量的特性,提高了破乳剂对微小液滴的捕捉能力及深度脱水效果。通过协同效应研究,选择合适的增效助剂与其他破乳剂进行复配,开发出D系列大分子高效原油破乳剂,解决了高酸、高硫原油的脱水问题,实现深度脱水的目标,可将脱后原油含水降至0.2%以下。该系列破乳剂在非洲各油田得到了广泛应用,解决了生产过程中的实际问题,确保了油田的正常生产。

关键词: 破乳剂, 高硫原油, 高酸原油, 大分子, 乳状液, 脱水