DID DEAD ANIMALS REALLY SPEW FROM THE IEA-GHG WEYBURN-MIDALE CO2 MONITORING AND STORAGE PROJECT?
In January 2011, a local landowner supported by a consultant’s soil gas survey, claimed they had conclusive proof that the “source of the high concentrations of CO2 in soils … is clearly the anthropogenic CO2 injected into the Weyburn reservoir”. These claims quickly attracted local, provincial, national, and international media attention alerting the world to the “leakage” at the Weyburn CO2-EOR project and calling into question the safety of geological sequestration in general.
A careful look at the data reveals a different story. Twenty six soil gas samples were collected in August 2010, from shallow (< 1m) drill holes and analyzed for CO2 concentrations and short-chain hydrocarbons. Six samples were analyzed for concentrations of stable isotopes of carbon, and four water samples from shallow dugouts were sampled for BTEX and hydrocarbons. Measured CO2 concentrations ranged from approximately 1 to 11%, methane concentrations ranged from approximately 1.2 to 24 ppm, and 13C/12C isotope concentrations ranged from -21.5 to -22.9 per mil. Hydrocarbons and BTEX in the water samples were below detection limits.
Volumes of data collected by more than 80 international researchers in the IEA-GHG Weyburn-Midale research project, do not support the claim(s) of anthropogenic CO2 leakage from the Weyburn reservoir. A comprehensive geological, geophysical, hydrogeological, and geochemical site characterization combined with background and on-site soil gas monitoring, integrated with numerical simulations of CO2 movement has not detected any evidence of migration of CO2 above the regional subsurface seal. Shallow soil gas monitoring near the Weyburn field, and in the CO2-EOR area, have detected transient elevated CO2 concentrations of similar magnitudes, all attributed to near-surface biogenic and/or pedogenic processes. This talk will highlight relevant data collected by the research project and contrast it with claims of leakage.