The Effect of Rotation Rate on Gel Strength and Dynamic Yield Strength of Thixotropic Oil Well Cements Measured Using a Shear Vane

Abstract

A six‐bladed vane was used to measure the gel strength and dynamic yield strength of a thixotropic cement slurry of a type used in oil well cementing. It was established that when the combined parameters of rotation speed, measuring system stiffness, and gel strength give a time to maximum torque of less than 100 milliseconds, sophisticated data recording systems are necessary. It is shown that gel strength is only marginally affected by nominal vane rotation speed between 0.06 and 6 rpm whereas dynamic yield strength is sensitive to rotation rate in this speed range.