Qian Yuchuan, Xu Tianhong, Yao Haiyuan, Song Guangchun, Li Yuxing, Wang Wuchang, Yu Xinran, Xu Zheng
Shandong Provincial Key Laboratory of Oil, Gas and New Energy Storage and Transportation Safety, China University of Petroleum (East China), Qingdao, Shandong 266580, PR China.
College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, PR China.
Langmuir. 2025 Jul 1;41(25):16328-16341. doi: 10.1021/acs.langmuir.5c01654. Epub 2025 Jun 16.
Flow blockage caused by hydrate deposition in deep-water-oil and gas pipelines seriously affects the safety of energy transmission. The structural stability of hydrates has a direct influence on the assessment of the development of hydrate deposition in pipelines, and the situation under hydrate-inhibitor-containing conditions may be more complicated. The effect of inhibitors on the structural stability of hydrate deposition under the action of flow scouring has not yet been clarified. The present study was based on the process of hydrate formation transformation under kinetic inhibitor-containing pectin conditions. The "concentration effect" of the pectin system causes the hydrate particle morphology to change from acicular to punctate. For the first time, the evolution model of microscopic fracture in the hydrate bed under the action of flow scouring in the high-mass transfer region was clarified. It was determined by microscopic dynamic data that there was reformation and filling of hydrate particles between the flow scouring fracture as well as growth and extension behavior, and a chain initiation-induced nucleation effect of hydrate particles was proposed. It was further found that pectin weakened the cohesion of hydrate particles, but when the pectin concentration was 0.25 wt %, there was an abnormal increase in cohesion. Enhanced mass transfer due to structural destabilization of the hydrate layer may be responsible for the continued formation and transformation of pectin system hydrates at low shear rates. This study shows for the first time the correlation between inhibitor concentration and hydrate conversion from the perspective of structural stability of hydrate beds and provides a theoretical basis for the engineering application of green inhibitors.
深水油气管道中水合物沉积造成的流动堵塞严重影响能量传输安全。水合物的结构稳定性对管道中水合物沉积发展的评估有直接影响，含抑制剂条件下的情况可能更复杂。流动冲刷作用下抑制剂对水合物沉积结构稳定性的影响尚未明确。本研究基于含动力学抑制剂的果胶条件下水合物形成转变过程。果胶体系的“浓度效应”使水合物颗粒形态从针状变为点状。首次阐明了高传质区域流动冲刷作用下水合物床微观裂缝的演化模型。通过微观动态数据确定，在流动冲刷裂缝之间存在水合物颗粒的再形成和填充以及生长和扩展行为，并提出了水合物颗粒的链引发诱导成核效应。进一步发现，果胶削弱了水合物颗粒的内聚力，但当果胶浓度为0.25 wt%时，内聚力出现异常增加。水合物层结构失稳导致传质增强，可能是果胶体系水合物在低剪切速率下持续形成和转变的原因。本研究首次从水合物床结构稳定性角度揭示了抑制剂浓度与水合物转化率之间的相关性，为绿色抑制剂的工程应用提供了理论依据。
