天然气水合物藏裂缝注热的数值模拟研究

Numerical Investigation on Hot Water Injection Process Along Fractures of Methane Hydrate Reservoirs

天然气水合物因其能量密度大、储量丰富、无污染等特点而被认为是一种新型的替代能源,如何提升天然气水合物储层渗透率是实现其商业化开采的关键。本研究提出使用人工压裂技术在水合物储层中形成裂缝网络,然后再将高温水注入储层来提升储层渗透率,并对沿裂缝注水过程进行了数值模拟。结果表明:人工压裂后,注入储层的热水能够到达储层深处,形成高温区和高渗透区,且注水量越大,形成的高渗透区范围越大。

Natural gas hydrate(NGH)is considered one of the most promising alternative energy resources because of its high-energy density,abundance in nature and cleanness.The key challenge for commercial exploitation and utilization of this energy resource is how to increase the permeability of NGH reservoirs which benefits gas production efficiency.This study proposes a method for increasing NGH reservoir permeability by the combination of applying hydraulic fracturing method to induce artificial fractures in NGH reservoirs and then injecting hot water into the fractures,and conducts a numerical investigation on the hot water injection process.The results indicate that hot water can flow into the deep region of NGH reservoir,along which a high-temperature and high-permeability zone forms,and the higher the injection rate,the larger this zone.