Time and Shear Effects on Rheological Properties of Crosslinked Fluids—An Evaluation Method

Abstract

Summary This paper presents a new method for evaluating time and shear effects on flow properties of crosslinked polymer fluids. An apparatus has been designed and assembled to simulate crosslinking the fluid on the fly and fluid flowing down the well, through perforations, and in the fracture. Laminar and turbulent flow properties can be evaluated simultaneously. The results—such as turbulent friction pressure, effect of pipe and perforation shear on the rheological properties of fluids in the fracture, viscous properties in the fracture, and temperature stability of fluids—can be obtained from the data gathered with the apparatus. Several different polymer-crosslinker systems have been evaluated. Results show that a hydroxypropyl guar (HPG)/delayed titanate crosslinker system exhibits practically base-gel friction pressure in turbulent flow, excellent viscous properties, and good temperature stability in fracture flow. Perforation shear has almost no effect on the rheological properties of the HPG/delayed crosslinker system. Also, this system exhibits better viscous properties at lower fracture flow rates.