WBPC 2019 Abstract #26:
The Aquistore CO2 Storage Project is an integral component of SaskPower’s Boundary Dam CO2 Capture Project and is located in southeastern Saskatchewan, Canada. The measurement, monitoring and verification program of Aquistore presents an opportunity to develop and apply effective methods for monitoring CO2 storage sites, ensure conformance of the storage process through continuous monitoring and provides experience that could be applied in unconventional reservoir development. The Aquistore site includes one injection well and one observation well approximately 150m offset from the injection well. These are the two deepest wells ever drilled in Saskatchewan, the Aquistore injection well at a total depth 3396 metres and the observation well at a total depth of 3400 metres. Both wells are completed with various measurement and monitoring equipment, including distributed temperature sensing lines (DTS), distributed acoustic sensing line (DAS) and tubing/casing-conveyed pressure gauges at different levels to measure pressure and temperature changes downhole during to CO2 injection. This presentation will focus on the completion of the CO2 injection well and its dynamic behavior since CO2 injection began on April 16, 2015 through to November 1, 2017 when approximately 110,000 tonnes of CO2 had been injected at the site. Details of the completions along with detailed downhole pressure/temperature data captured during the cementing operations of the injection well will be discussed. Thermal cycles during CO2 injection operations, which can be as high as ±50C, can result in a pressure build up in the annular fluid, and potentially place extra forces on the packer due to expansion/contraction of the tubing. During the span of 15 months analyzed, CO2 injection starts and ends periodically leading to various annular pressure behavior. To assess the state of the CO2 injection well, a downhole camera was run in the well on May 9, 2017. Results from these observations are discussed regarding the quality of the downhole perforations, variations in downhole temperature following an extended shut-in period and conditions of the fluids in the well with respect to salt precipitation.