API TR 13TR3-2018

This report is intended to serve as a guide for the selection of appropriate techniques to determine theparticle size distribution (PSD) of relatively large dry solid additives for drilling fluids, especially lostcirculation materials (LCMs). Detailed procedures for the utilization of any specific PSD method are notincluded. The technician should refer to and be guided by the measurement equipment manufacturer’sinstructions. The particulates range in size from approximately one micron to as much as several millimetersin diameter, and are considered “granular” in shape, i.e. relatively isometric (of similar length, width, andheight). The recommendations in this technical report generally are not applicable to the measurement of thePSD of nonisometric (high aspect ratio) materials such as fibers or flakes.