某深水气田乙二醇脱盐系统影响因素分析与措施

Influencing Factor Analysis and Measures of Ethylene Glycol Desalination System in a Deepwater Gas Field

乙二醇(简称MEG)作为防止深水气田水合物形成的抑制剂广泛地应用于天然气田的开发生产中,为解决某深水气田乙二醇回收系统出现的结垢与腐蚀问题,对乙二醇回收工艺中脱盐系统的影响因素进行了分析,发现二价金属阳离子、羧酸盐、化学药剂配伍性、碳酸氢钠、含氧量、完井液成分、乙二醇降解、苯系物等因素会加剧脱盐系统的结垢与腐蚀。结合工艺实践,通过对乙二醇脱盐系统采用耐腐蚀不锈钢管材和螺旋式加热器、加入除氧剂降解、提前进行药剂配伍性测试、定期排放高黏度废液等应对措施,不仅可以降低脱盐系统结垢与腐蚀的风险,同时也可减少乙二醇的损耗,脱盐系统可长期稳定运行。

Ethylene glycol (MEG) is widely used as an inhibitor to prevent hydrate formation in deep-water gas fields in the development and production of natural gas fields. In order to solve the problem of scale formation and corrosion in ethylene glycol recovery system of a deepwater gas field, influencing factors of desalination system for ethylene glycol recovery process are analyzed. It is found that the factors such as divalent metal cation,carboxylate,chemical compatibility,sodium bicarbonate,oxygen con-tent, completion fluid composition, degradation of glycol will aggravate scale formation and corrosion of the desalination system. Based on process practice, through measures to the desalination system such as adopting the corrosion resistance stainless steel pipes, adding deoxidant to degrade, conducting chemical compatibility test early and discharging waste liquid with high viscosity periodically, scaling and corrosion risk of desalination system is reduced, and the consumption of ethylene glycol is also re-duced,thus to achieve long-term stable operation of desalination system.