用分子动力学模拟甲烷水合物热激法结合化学试剂法分解

用分子动力学模拟方法研究甲烷水合物的热激法，化学试剂法，以及热激法结合化学试剂法分解，系统研究温度为277K和340K时添加液态水(WTR)和30wt％乙二醇(EG)溶液对水合物分解的影响.模拟显示WTR与水合物表面水分子形成氢键，破坏水合物原有的氢键平衡，造成笼状结构坍塌，水合物分解.EG分子中的羟基与水合物表面水分子形成氢键，从而破坏原有的稳定结构，造成水合物笼状结构被破坏，达到促进水合物分解，释放甲烷气体的效果.比较温度为277K和340K时添加WTR和30wt％EG溶液对水合物分解效果得出EG(340K)> WTR(340K)>EG(277K)>WTR(277K)，热激法结合化学试剂法能更好促进水合物分解.

Molecular dynamics simulation of methane hydrate dissociation by thermal stimulation in conjunction with chemical injection method

The characteristics of methane hydrate dissociation in the presence of thermal stimulation, chemical injection, and thermal stimulation in conjunction with chemical injection method were investigated by molecular dynamics simulation. The effect of the injection of liquid water (WTR) and 30wt% ethylene glycol (EG) solution at 277K and 340K on methane hydrate dissociation was studied. The results showed the hydrogen bonds between WTR molecules and the water molecules on the hydrate surface were formed，which destroyed the original hydrogen bond balance of the hydrate. Therefore, the clathrate structure of hydrate collapsed, and the hydrate dissociated. The hydrogen bonds was formed obviously between hydroxyl groups of EG molecules and the water molecules on the hydrate surface; this caused the original stable clathrate structure of the hydrate to be destroyed and collapse, and, furthermore, promoted the dissociation of the methane hydrate and the release of methane gas. Compared with the effects of injecting WTR and 30wt% EG solution at 277K and 340K on the dissociation of methane hydrate, the effectivences was found to be: EG(340K)> WTR(340K)>EG(277K)>WTR(277K). The thermal stimulation in conjunction with chemical injection method can more effectively promote the dissociation of hydrate.