致密气储层压裂液渗吸核磁共振微观分析

Microscopic analysis of fracturing fluid percolation NMR in tight gas reservoirs

为探明压裂液渗吸过程中流体运移规律,结合微观核磁共振技术与宏观室内模拟实验,对致密气藏压裂液渗吸过程进行研究,得到了压裂液不同注入时间下的磁共振成像及压裂液渗吸过程一维投影结果,并应用相应的评价参数与数据处理方式,实现了压裂液渗吸过程的量化分析。研究表明,压裂液进入岩心的深度与渗吸时间呈正比,当深度达到某一定值时,压裂液便不再进入;压裂液渗吸速度随着渗吸时间增加而减小,初期渗吸速度降低幅度最大,中期渗吸速度下降幅度有所缓减,而后期渗吸速度降低幅度最小。

In order to investigate the fluid transport law in the fracturing fluid seepage process,combined with micro NMR technology and macro indoor simulation experiment,the imbibition process of fracturing fluid in tight gas reservoir was studied,and the magnetic resonance imaging and one dimensional projection results of fracturing fluid seepage process under different injection times of fracturing fluid was obtained.The study showed that,the depth of fracturing fluid into the core is proportional to the seepage time,and when the depth reaches a certain value,the fracturing fluid will no longer enter;the seepage rate of fracturing fluid decreases with the increase of seepage time,and the decrease of seepage rate at the beginning is the largest,the decrease of seepage rate at the middle is slow,and the decrease of seepage rate at the end is the smallest.