一种抗高过冷度水合物动力学抑制剂的合成与评价

Synthesis and evaluation of a kinetic inhibitor against high undercooling hydrate

天然气在高压低温并具有游离水的环境条件下极有可能在井下和地面管道中生成天然气水合物,造成井筒的堵塞以及其他安全问题。注入动力学抑制剂是目前最环保高效的方法,但在高过冷度的环境下,抑制性能微弱,因此有必要研制具有抗高过冷度的新型动力学抑制剂。制备了含多重氢键的功能单体UpMA,将N-乙烯基吡咯烷酮(NVP)作为主单体,含多重氢键结构的UpMA单体作为功能单体,二者共聚制备出新型动力学水合物抑制剂PVP-UpMA,采用温压扭矩法综合评价水合物抑制剂的抑制成核性能以及抑制生长性能,并通过考察耐用过冷度、诱导时间以及气体消耗量等参数评价该抑制剂在水合物生成过程中的抑制性能。结果表明,PVP-UpMA的耐用过冷度随着质量分数的增大而小幅度增大,且1%PVP-UpMA的耐用过冷度(6.45℃)明显优于商业PVPk90(4.11℃)以及Luvicap EG(3.36℃);1%PVP-UpMA抑制性能随着过冷度的增加而降低,但在高过冷度(7.5℃)下诱导时间仍超过200 min,气体消耗量同纯水相比降低75%以上;PVP-UpMA在7.5℃过冷度下最佳质量分数应低于1.5%。虽然PVP-UpMA环境效益一般,但经济效益较好,有望替代现场传统热力学抑制剂。

Natural gas under high pressure and low temperature environment with free water is very likely to generate gas hydrate in downhole and surface pipelines,causing wellbore plugging and other safety issues.Injecting kinetic inhibitors is the most environmentally friendly and efficient method at present,but in the environment of high undercooling,the inhibition performance is weak,so it is necessary to develop new kinetic inhibitors with high undercooling resistance.In the experiment,N-vinylpyrrolidone(NVP)was used as the main monomer,and UpMA monomer with multiple hydrogen bond structure was used as the functional monomer.The two copolymerized to prepare a new kinetic hydrate inhibitor PVP-UpMA.At the same time,the temperature and pressure torque was used.The inhibitory nucleation and growth inhibitory properties of hydrate inhibitors were comprehensively evaluated by the method,and the inhibitory properties of the inhibitor in the hydrate formation prcess were evaluated by examining parameters such as durability undercooling,induction time and gas consumption.The results showed that the durable undercooling degree of PVP-UpMA increased slightly with the increase of concentration,and the durable undercooling degree(6.45℃)of 1%PVP-UpMA was significantly better than that of commercial PVPk90(4.11℃)and EG(3.36℃);the inhibition performance of 1%PVP-UpMA decreased with the increase of subcooling degree,but the induction time still exceeded 200 min at high subcooling degree(7.5℃),and the gas consumption decreased by more than 75%compared with pure water;The optimal concentration of PVP-UpMA should be lower than 1.5%at 7.5℃supercooling.The environmental benefits of PVP-UpMA are average,but the economic benefits are good,and it is expected to replace traditional thermodynamic inhibitors on site.