Temperature monitoring using Distributed Temperature Sensing (DTS) technology

Abstract

The applicability of Distributed Temperature Sensing (DTS) as a technology to monitor CO2 flow within CO2 injection zones at the inter-well scale, as well as to detect CO2 leakage into the overburden, is studied in this paper An onshore CO2 injection site in the U.S. Gulf Coast that has received more than 5 million metric tons of CO2 is the setting for this study. Temperature measurements were acquired every meter along two dedicated CO2 observation wellbores, with sample rates that ranged from 2 to 15 minutes, from November 2009 through November 2010 and from September 2011 to January 2012. More than five hundred million temperature measurements were recorded during these time periods. As part of our analysis, we discuss the thermal processes and mechanisms expected to contribute to the thermal signal recorded by the DTS system, as well as the temperature changes induced by the temperature discrepancy between the injectate and the reservoir fluids. Results indicate that DTS can be a useful supporting tool when used in combination with pressure monitoring and imaging technologies.