METHODS FOR PREDICTING DYNAMIC SAG USING VISCOMETER/RHEOMETER DATA

摘要

A method comprising: measuring rheological data for a plurality of fluids having particulates 5 suspended therein, wherein the rheological data is selected from the group consisting of: a shear stress, a yield stress, a viscosity, a shear-thinning index, and any combination thereof; applying a pseudo-plastic model and a visco-plastic model to the rheological data to produce characteristic parameters for each of the plurality of 10 fluids; applying the characteristic parameters for each of the plurality of fluids to an equation to predict a dynamic sag rate for each of the plurality of fluids; and formulating a drilling fluid based on the dynamic sag rate for each of the plurality of fluids so as to minimize sag in the drilling fluid.