Fluid-Diversion Monitoring: The Key to Treatment Optimization

Abstract

Summary In stimulation and injection treatments for removing or preventing formation damage, placement of the injected fluids is essential. Throughout the years, several diversion and placement techniques have been applied to obtain a desired fluid placement. A recent development is the application of distributed temperature sensing (DTS) to monitor the temperature profiles along the wellbore in real time during these treatments. Recent case histories showed that fluid placement can be quantified. Quantification of fluid distribution enables one to determine the flow distribution both before and after a diverter stage so that the diversion effect can be quantified. This paper discusses several case histories where DTS was applied to quantify the effectiveness of different diverters. The effects of chemical diverters, such as relative permeability modifiers (RPMs) and in-situ-crosslinked acids (ICAs), and more-traditional diverters, such as rock salt, are discussed. Because of the advanced monitoring used with the temperature profiles, both the immediate and the sustained effect of the diverters can be measured. The changes in the flow distribution are not limited to diverters. Reactive fluid or changes in flow rate can change the flow distribution as well. These effects were measured during the stimulation treatments. The post-treatment analysis of the measured temperature profiles in combination with treatment pressures and flow-rate information resulted in accurate knowledge of the effectiveness of the different diverters and stimulation effects over time. This knowledge will be used in future treatments to help optimize volumes, rates, fluid systems, and the selection of the appropriate diverter.