Rick Chalaturnyk

University of Alberta

Field-based observations for CO2 geological storage from 7 years of dynamic CO2 injection .

at the Aquistore CO2 storage site

The Aquistore CO2 Storage Project is an integral component of SaskPower’s Boundary Dam CO2 Capture Project located in southeastern Saskatchewan, Canada. Operational synergies between the capture facility (supply) and CO2-EOR (demand) require excess CO2 to be transported via pipeline to the Aquistore site where it is injected into a hyper-saline fluid filled sandstone formation at approximately 3300 m depth. The reservoir temperature is approximately 120 °C, and average reservoir pressure is 35 MPa. Preliminary laboratory measurements on core plugs gave average values of porosity and permeability, 6% and 5 mD respectively. The Aquistore site includes one injection well and one observation well approximately 150m offset from the injection well. 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 focuses on dynamic responses that have been recorded since the completion of the CO2 injection well and the start of CO2 injection on April 16, 2015. This has provided an unprecedented opportunity to collect monitoring data on the dynamics of phase changes (i.e. supercritical to liquid to gas phase shifts) from the wellhead to the geological formation associated with CO2 injection. Real time monitoring data of these phase changes in the injection stream under fully integrated operational conditions provides unparalleled information for understanding geological storage under these conditions and optimizing completion systems. Objective of the presentation is to convey the message that you should not underestimate the complexity of CO2 injection behaviour for full scale projects. Additional studies have been conducted on the potential of utilizing the elevated temperature CO2 plume for geothermal power generation. The talk will highlight simulation studies completed to support this concept.