UPDATE OF A TRIAL OF CO_(2)-BASED GEOTHERMAL AT THE ST. JOHNS DOME

摘要

In September of 2010, GreenFire Energy received a DOE grant to attempt a real-world trial of CO_(2)-based geothermal energy (CO_(2)G) at a site on the St. Johns-Springerville CO_(2) Dome near the Arizona-New Mexico border. Though CO_(2)G was proposed in 1998, and there has been a significant amount of computer modeling, there has never until now been an attempt to test the idea in the field. The chosen site is uniquely suited for testing CO_(2)G, as it incorporates the St Johns CO_(2) reservoir, from which approximately 450 MM tons of CO_(2) is recoverable from relatively shallow deposits. The CO_(2)-bearing formations overlie a moderate-temperature geothermal area. Thus the plan is to produce CO_(2) from the shallow formations, compress as necessary to obtain supercritical CO_(2), which will then be injected into the hot basement granite/schist formation containing the geothermal heat. This paper will describe the work to date, including a summary of the pertinent literature and early results from passive seismic monitoring of the site. Plans for further research will also be discussed.