Evaluating the impacts and capabilities of long term subsurface storage in the context of carbon sequestration in the San Juan basin, NM and CO

Abstract

Abstract Effective evaluation of CO2 storage capacity is essential for long-term planning and design of large-scale CCS. To support ongoing field-testing of geological CO2 sequestration by the Southwest Regional Partnership on Carbon Sequestration (SWP), we are developing reservoir models to evaluate capacity and potential environmental impacts of large-scale CO2 injection. Specifically, we are developing detailed models of CO2 injection of a combined sequestration and enhanced coalbed methane production project in the San Juan Basin, New Mexico, as part of the SWP’s field validation testing program. Injection in San Juan Basin coals is slated to begin in late 2008. Our analytical and numerical model simulation results suggest that injection in the Fruitland Coal formation will create significant pressure pulses that will migrate beyond its caprock, the low permeability Kirtland Shale formation, and impact formations above. We used observed temperature and heat flow data to calibrate basin- scale permeability, and our model results to date suggest that existing San Juan permeability measurements are underestimated compared to meaningful basin-scale values. Local measurements typically ignore fractures, faults, and high velocity conduits which are abundant at the basin scale. Simulation results indicate that the Fruitland Coal and other adjacent formations may carry much larger quantities of water and heat than previously anticipated. Because of this significant regional permeability, we hypothesize that injection and production over long periods of time may affect regional hydrodynamics, but it is not clear if any impacts to underground sources of drinking water (USDWs) will occur because of their relative distance from injection sites. This research is being carried out to support design and interpretation of ongoing field-testing by the Southwest Regional Partnership on Carbon Sequestration. The authors gratefully acknowledge the US Department of Energy and NETL for sponsoring this project.