Hyperspectral Geobotanical Remote Sensing for CO2 Storage Monitoring

This project's goal is to develop remote sensing methods for early detection and spatial mapping, over whole regions simultaneously, of any surface areas under which there are significant CO2 leaks from deep underground storage formations. If large amounts of CO2 gas percolated up from a storage formation below to within plant root depth of the surface, the CO2 soil concentrations near the surface would become elevated and would affect individual plants and their local plant ecologies. Excessive soil CO2 concentrations are observed to significantly affect local plant and animal ecologies in our geothermal exploration, remote sensing research program at Mammoth Mountain CA USA. We also know from our geothermal exploration remote sensing programs, that we can map subtle hidden faults by spatial signatures of altered minerals and of plant species and health distributions. Mapping hidden faults is important because in our experience these highly localized (one to several centimeters) spatial pathways are good candidates for potentially significant CO2 leaks from deep underground formations. The detection and discrimination method we are developing uses primarily airborne hyperspectral, high spatial (3 meter) with 128 band wavelength resolution, visible and near infrared reflected light imagery. We also are using the newly available ''Quickbird'' satellite imagery that has high spatial resolution (0.6 meter for panchromatic images, 2.4 meters for multispectral). We have a commercial provider, HyVista Corp of Sydney Australia, of airborne hyperspectral imagery acquisitions and very relevant image data post processing, so that eventually the ongoing surveillance of CO2 storage fields can be contracted for commercially. In this project we have imaged the Rangely Colorado Oil field and surrounding areas with an airborne hyperspectral visible and near infrared reflected light sensor. The images were analyzed by several methods using the suite of tools available in the ENVI commercial hyperspectral image processing software. We have also begun to use the high resolution (0.6 meter) commercial satellite QuickBird in our technology development. This hyperspectral imaging project for CO2 leakage monitoring has focused on using the extensive hyperspectral imagery set that we acquired of the Rangely CO enhanced oil recovery field in August 2002. We have accomplished extensive analysis of this imagery. We have created highly detailed maps of soil types, plant coverages, plant health, local ecologies or habitats, water conditions, and manmade objects throughout the entire Rangely Oil field and surrounding areas. The results were verified during a field trip to Rangely CO in August 2003. These maps establish an environmental and ecological baseline against which any future CO2 leakage effects on the plants, plant habitats, soils and water conditions can be detected and verified. We have also seen signatures that may be subtle hidden faults. If confirmed these faults might provide pathways for upward CO2 migration if that occurred at any time during the future. We have found a result that was unexpected, new to us, and potentially very important to the task of monitoring for CO2 that has leaked to within the plant root depths near the surface. The discovery is that one of our analysis techniques has picked out finely detailed mapping of local ecologies. Some of which are found to extend across the entire Rangely oil field and into the surrounding areas. These ecologies appear to be made up of a fairly narrow range of percentage admixtures of two or three very specific plant types and soil types. It is likely that any large amounts of CO2 reaching the root depth near the surface would begin to modify the shapes of the habitats. These habitat changes will be easy to detect by repeat imaging of the area. The habitat modification signature is probably detectable earlier following the start of CO2 build up in the soil, than looking for individual plant stress. We strongly recommend a long term research effort that will establish what CO2 soil concentration levels produce observable changes in the biosphere and the corresponding subtle and complex ecological distributions in various environments (including terrestrial and marine). This is an extremely important and highly relevant task for CCP SMV to pursue in our opinion.