含动力学抑制剂体系甲烷水合物微观分解过程

Microscopic Decomposition Behavior of Methane Hydrate Formed in the Presence of Kinetic Inhibitor

注入低剂量水合物动力学抑制剂是防治油气管道中水合物堵塞的有效技术之一。为了实现高效、经济解堵,非常有必要展开动力学抑制剂对水合物分解行为影响规律的研究。利用粉末X射线衍射仪和激光共聚焦拉曼光谱仪在常压、-10℃条件下原位观测纯水体系和含动力学抑制剂聚乙烯基己内酰胺(PVCap)体系的甲烷水合物微观分解过程。结果显示,相比纯水体系,PVCap的存在会减弱sI型甲烷水合物“自保护”效应,加速水合物的分解。甲烷气体在水合物大、小笼中的含量同步降低,且相对含量基本保持恒定,说明PVCap不影响水合物以晶胞为单位进行整体分解。六角冰的(100)和(002)晶面峰面积随时间的变化不同步,且在纯水体系和含PVCap体系中呈现的变化趋势截然不同。

Injecting low-dosage kinetic hydrate inhibitor(KHI)was one of the most efficient ways to prevent hydrate plugs in oil and gas pipelines.Aiming to seek plug removal techniques with high efficiency and economy,it was necessary to study the effect of KHI on the hydrate dissociation.The microscopic decomposition behavior of methane hydrate in pure water and poly(N-vinylcaprolactam)(PVCap)was investigated by using a powder X-ray diffractometer and laser confocal Raman spectrometer at-10oC and atmosphere pressure.The results revealed that PVCap could weaken the“self-preservation”effect of sI methane hydrate and accelerate the hydrate dissociation rates.The methane contents in large and small hydrate cages decreased synchronously,and the relative content remained constant.The hydrate collapsed as a unit cell,whether with PVCap or without.Time-dependent integral intensities of hexagonal ice(100)and(002)peaks in pure water changed asynchronously and varied differently from those in systems containing PVCap.