Tunable diode laser absorption spectrometers for CO₂ wellhead and pipeline leakage monitoring: Experiences from prototype testing at the Illinois Basin - Decatur Project, USA

The Midwest Geological Sequestration Consortium is conducting a large-scale carbon capture and storage (CCS) project inDecatur, Illinois. USA to demonstrate storage of one million tonnes of carbon dioxide (CO₂) in the Mount Simon Sandstone, a deep saline formation at a depth of 2.100 meters. Injection began in November 2011. and as of August 2014. more than 900.000 tonnes of CO₂ have been injected. The project offers a unique opportunity to evaluate new diagnostic tools for CO2 monitoring at an active CCS site. During this investigation, prototype Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors in two configurations were constructed and successfully tested in 2013 at the Illinois Basin - Decatur Project field site: (1) a hand-held, mobile instrument called the Remote Carbon Dioxide Leak Detector (RCLD). intended for standoff inspection of CO₂ pipeline infrastructure to identify any leakage: And (2) a solar-powered wireless Open-Path Sensor (OPS) system intended for continuous monitoring of CO₂ concentrations integrated along a fixed 100-m path for human health and safety. Based on results from the prototype testing, it is expected that the OPS and RCLD designs can be refined and used at other CCS sites as part of an integrated environmental monitoring strategy.