A New Method for the Prediction of Sand Production Quality and Particle-Size Distribution in Slotted Screen Sand Control

Summary To capture the migration law of particles and the interaction mechanism between particles in the process of sand retention, a coupled computational fluid dynamics-discrete element method (CFD-DEM) model for sand migration through the slot was constructed to investigate the dynamics of sand deposition and blockage on the surface of the slot screen and to dissect the fundamental principles of microsand control. The fractal dimension of formation sand was incorporated to define the particle-size distribution (PSD) of diverse formation sands. This study examined how fluid viscosity, slot width, sand production concentration, fluid velocity, and the formation sand’s PSD affect the sand production through the slot and sand passing rate. The results show that lower fluid viscosity, flow rate, and smaller slot width are conducive to particle bridging and the sand production quality being small. The sand production concentration has an impact on the sand production. Under the condition of low concentration, the bridging is slow and the sand production is high. When the concentration increases to the condition that the bridge can be built quickly, the sand production quality increases with the increase in sand production concentration, and the shape of the coarser part of formation sand (larger than the pore diameter) has a higher impact on the sand production quality. To accurately predict sand production through this proposed method, it was essential to accurately determine the PSD of the coarser portion of the formation sand. At the same time, the sand production increased with the increase in fractal dimension. This paper provides further discussion of this new method for the prediction of sand production quality based on fractal dimension of formation sand, and develops a sand production management analysis software based on this method, which is convenient for engineering applications.