有机胺抑制蒙脱石水化机理的分子模拟

发布时间：2018-04-27 07:00

  本文选题：蒙脱石 + 分子动力学模拟　； 参考：《石油钻采工艺》2017年04期

【摘要】：井壁失稳一直是困扰石油钻井的重大技术难题,泥页岩水化是造成井壁失稳的最重要因素之一,作为最易吸水和泥页岩主要组分的蒙脱石是引起井壁失稳的根本性因素。利用分子模拟的方法,建立了有机胺类抑制剂与钠蒙脱石反应的分子结构模型,研究了甲酰胺和尿素等小分子有机胺类抑制剂对蒙脱石水化的抑制作用机理。胺类有机小分子抑制蒙脱石水化的能力与分子结构及官能团有关,甲酰胺和尿素均可与层间水分子及蒙脱石表面的氧原子形成氢键,抑制层间钠离子的水化,限制层间水分子及钠离子的自扩散。甲酰胺和尿素分子在不同浓度时对钠蒙脱石体系的密度和力学性能影响不同,但有相同的变化规律,即存在一临界浓度,低于此浓度时,胺类分子的加入可增大蒙脱石的密度,提高体系的力学性能,而高于此浓度时,体系密度减小,力学性能变差。甲酰胺和尿素都是在低浓度时能更好地发挥抑制作用,提高钠蒙脱石的稳定性,综合各参数对比分析,甲酰胺比尿素的整体作用效果好。
[Abstract]:Sidewall instability has always been a major technical problem for oil drilling. Shale hydration is one of the most important factors causing wellbore instability, and montmorillonite, which is the most easily absorbent and the main component of shale, is the fundamental factor causing wellbore instability. The molecular structure model of the reaction of organic amine inhibitors with sodium montmorillonite was established by molecular simulation. The mechanism of inhibition of organic amine inhibitors such as formamide and urea on the hydration of montmorillonite was studied. The ability of amines to inhibit the hydration of montmorillonite is related to the molecular structure and functional groups. Formamide and urea can form hydrogen bonds with interlaminar water molecules and oxygen atoms on the surface of montmorillonite and inhibit the hydration of interlaminar sodium ions. Limiting the self-diffusion of interlayer water molecules and sodium ions. The effect of formamide and urea on the density and mechanical properties of sodium montmorillonite was different at different concentrations, but there was a critical concentration, and the addition of amine could increase the density of montmorillonite. The mechanical properties of the system were improved, but when the concentration was higher, the density of the system decreased and the mechanical properties became worse. Both formamide and urea can play a better role in inhibition and improve the stability of sodium montmorillonite at low concentration. The overall effect of formamide is better than that of urea according to the comparative analysis of various parameters.
【作者单位】： 中国地质大学能源学院;中国石油大学石油工程学院(青岛);海洋水下设备试验与检测技术国家工程实验室;中国石油大学石油工程学院(克拉玛依);
【基金】：国家重点基础研究发展计划973项目“海洋深水油气安全高效钻完井基础研究”(编号:2015CB251200) 油气重大专项“大型油气田及煤层气开发”(编号:2016ZX05044003-001)
【分类号】：TE21
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本文编号：1809676