Sampling and analysis of local well water and surface soil gas (Strutt et al., 2005) were performed at the Weyburn field. The primary objectives of the soil gas analyses were to measure the natural background concentrations of CO2 and to ascertain whether CO2 or associated reservoir tracer gases were escaping to the near surface. Samples were collected three times over the course of two years on a regular spatial grid; additional samples that could represent possible vertical migration pathways were also collected at other sites in the surrounding area. Near-surface monitoring at the Frio Brine Pilot includes soil gas CO2 flux and concentration measurements, aquifer chemistry monitoring, and tracer detection of PFC with sorbents.
