神狐海域水合物降压-注热开采生产动态分析及参数优化

针对神狐海域天然气水合物藏,利用CMG-STARS软件开展数值模拟,分析了降压-注热驱替法下的开采动态,并对其主要开采参数的影响程度进行评估。研究结果表明:由于神狐海域水合物藏的地层的初始温度较高,本身热量充足,且该储层渗透率较低,注入热水扩散速度慢,注入热量只有很少一部分用于水合物的分解,热量损失大,因此注热效果不明显;综合考虑产气量、生产时间和累积气水比,建议在降压-注热开采的过程中井底压力设为2~3MPa。一步降压可以有效的缩短生产时间,从而提高经济效益,因此在不影响储层稳定性的前提下,开采过程中建议采用最快的降压速度进行降压生产。

Production dynamic analysis and parameter optimization of gas hydrate depressurization-heat injection mining in Shenhu sea area

CMG-STARS numerical simulation software is used to analyze production dynamic and evaluate the influence of the main production parameters of heat injection combined depressurization in Shenhu hydrate reservoir.The results show that,because of the high initial temperature (sufficient heat) and low permeability (slow diffusion rate of hot water) in Shenhu hydrate reservoir,only a small part of injected heat is used for hydrate decomposition,the heat injection effect is not obvious;Considering the gas production,production time and cumulative gas water ratio,it is suggested to set the bottom hole pressure at 2-3MPa.;One step depressurization can effectively shorten the production time and improve the economic benefits,therefore,on the premise of not affecting the stability of the reservoir,it is recommended to use the fastest depressurization speed in the production process.