A method of sizing plugging nanoparticles to prevent water invasion for shale wellbore stability based on CFD-DEM simulation

Abstract Plugging shale pores and throats with nanoparticles is an efficient and economic method of preventing water invasion to sustain shale wellbore stability. The nanoparticles size distribution is the key factor affecting plugging performance. Currently, the selection of nanoparticle size is usually based on empirical plugging rules and qualitative evaluation experiments. Experimental evaluations only can reflect the macroscopic plugging performance, but cannot reveal the microscopic plugging mechanism. In addition, the experiment for shale pores plugging is complicated and costly. Thus, it is very meaningful to propose a new method for sizing plugging nanoparticles based on simulation.