Entity

Time filter

Source Type

Sparks, NV, United States

Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.84K | Year: 2009

Geologic carbon sequestration has become an effective technology for reducing atmospheric levels of CO2 by capturing emissions and injecting them into underground geologic formations where they can be permanently isolated. In order to assure that the CO2 is effectively sequestered for long periods of time and to reduce the likelihood of local environmental impacts, cost-effective methods are needed to characterize potential sequestration reservoirs and to determine the extent, location, and nature of leaks from these reservoirs. Electrical Resistance Tomography (ERT) is a geophysical tool that has been used successfully to image the electrical resistivity of the subsurface. In particular, ERT is especially sensitive to fluid content in pores. This project will develop technology for using ERT to monitor the movement of sequestered CO2, by measuring changes in the electrical resistivity of the subsurface, both in the saturated and vadose zone. The proposed ERT system will consist of many inexpensive, self-contained units that would communicate with each other through a distributed wireless network. The capital expense of such a system would be relatively small. Operating expenses, once the system is automated, also would be small. Commercial Applications and other Benefits as described by the awardee: Carbon sequestration is becoming recognized as an effective technology for the mitigation of excessive CO2 emissions. With continued regulatory enforcement and tax incentives, CO2 sequestration monitoring could become a multi-billion dollar market


Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.58K | Year: 2009

Although a number of new technologies are becoming available for environmental site remediation, the successful application of these technologies often depends on detailed knowledge of the site hydrogeology and the distribution of the contaminants. Recent research has demonstrated that the induced polarization (IP) method ¿ and, in particular, the spectral induced polarization (SIP) method ¿ may be able to provide detailed petrophysical data, including estimates of grain-size distributions and/or distributions of hydraulic conductivity. Such estimates will allow the delineation of aquifers and the determination of the integrity of aquitards. In addition, it is widely accepted that IP data can provide estimates of subsurface cation exchange capacity, which in turn could be used to estimate retardation factors for the movements of many inorganic contaminants. Using the SIP method, this project will develop a non- or minimally-invasive geophysical method that would provide order-of-magnitude estimates of subsurface permeability and/or grain size distributions. Commercial Applications and other Benefits as described by the awardee In addition to the market for environmental remediation, the technology should have application to ground-water resource evaluation. Another avenue of commercialization would involve providing accessories and software to research, university, and government agencies


Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 381.93K | Year: 2010

An effort is underway by the U.S. DOE to develop cost-effective and environmentally sound technologies in order to help to stabilize atmospheric concentrations of CO2 and to reduce greenhouse gas emissions. There is a significant need for economical methods to characterize potential sequestration reservoirs as well as determine the extent, location and nature of leaks from reservoirs both to assure that CO2 is effectively sequestered for long periods of time, and to reduce the likelihood of local environmental impacts. Electrical Resistivity Tomography (ERT) is a geophysical tool that has been used successfully to image the electrical resistivity of the subsurface, and is especially sensitive to pore fluid content. ERT is capable of monitoring movement of sequestered CO2 by measuring the change in the electrical resistivity of the subsurface, both in the saturated and vadose zones. Our ERT system under development consists of many, inexpensive, self-contained units that communicate with each other through a distributed wireless network. The capital expense of such a system would be relatively small. The operating expenses, once the system is automated, would also be small. In the Phase I project, the prototype system design was completed, a preliminary version of a new survey design strategy was implemented and a strategy for employing multiple, simultaneous current sources was developed. The new strategy will increase signal to noise levels and enhance target resolution. In Phase II Year 1 we will complete fabrication of the prototype system and operation software and adapt imaging routines for the multi-source strategy. We will complete all design upgrades and perform unit as well as full scale field tests in Year 2. Commercial Applications and Other Benefits There is a significant need for cost-effective methods to monitor CO2 sequestrationreservoirs in order to reduce the likelihood of local environmental impacts. This project will develop a cost-effective method of monitoring sequestration reservoirs for potential leakage pathways and for reservoir integrity using a geophysical method, Electrical Resistivity Tomography (ERT)


Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 493.75K | Year: 2006

One of the most widely used geophysical methods for monitoring flow within the shallow subsurface is Electrical Resistivity Tomography (ERT). The latest generation of ERT systems can monitor data to a precision of around 1%, allowing in situ changes to be interpreted within a few percent. In turn, subsurface temperature changes can be monitored to within a few degrees Centigrade, low levels of tracers ¿ only slightly higher than background variations ¿ can be tracked, and fracture propagation on a site of several thousand square meters can be watched. This project will make improvements to hardware and data collection procedures that will raise ERT precision by an order of magnitude. In Phase I, modifications were made to a number of interdependent hardware and software systems, resulting in reductions in both random and systematic noise sources. Random noise was reduced by implementing longer data averaging periods and by improving stacking algorithms. Systematic noise was reduced by improving hardware design, including the isolation of transmitter and receiver paths in the multiplexer and the use of temperature-stabilized higher-precision components to improve calibration. Electrode and cable effects also were found to be larger sources of noise than anticipated. Phase II will investigate the use of alternative materials for the electrode and cable, in order to mitigate the noise from these sources. Alternative data collection strategies will be investigated. Improvements to hardware and software will focus on calibration. Field trials will be held in difficult environments, such as the Idaho National Laboratory, Box Canyon fractured rock study area, and Vadose Zone Research Park. Commercial Applications and other Benefits as described by the awardee: An improved ERT technology should increase measurement precision, increase resolution, and enhance effectiveness in existing monitoring applications without significantly increasing costs. These improvements should broaden the range of applications for the method, particularly in monitoring flow in the shallow subsurface. The DOE complex alone has been estimated to contain 200 million cubic meters of contaminated soils, including those at the Hanford Reservation, the Savannah River Site, the Idaho National Laboratory, and the Nevada Test site


Breen S.J.,University of California at Irvine | Carrigan C.R.,Lawrence Livermore National Laboratory | LaBrecque D.J.,Multi-phase Technologies, Llc | Detwiler R.L.,University of California at Irvine
International Journal of Greenhouse Gas Control | Year: 2012

Field-scale studies have shown electrical resistivity tomography (ERT) to be an effective tool for imaging resistivity anomalies and monitoring infiltration events in the near subsurface. ERT also shows potential for monitoring supercritical-CO 2 injections, despite deployment challenges in the deep subsurface. We present results from analog bench-scale experiments aimed at evaluating the ability of ERT to quantify the volume and spatial distribution of a resistive fluid injected into a brine-saturated porous medium. Our experiments represent a well-controlled analog for supercritical-CO 2 injection into deep brine aquifers. We injected measured volumes of air into translucent chambers filled with quartz sand, lined with electrodes, and saturated with a low resistivity salt solution. Between injections, a CCD camera captured high-resolution images, and an ERT data acquisition system scanned the chamber. Processing of the CCD images using quantitative visualization techniques resulted in high-resolution measurements of the spatial distribution and saturation of the injected gas. Direct comparison to inverted resistivity fields then provided a quantitative measure of the ability of ERT to estimate the total volume of injected gas and its spatial distribution within the chamber. We present results from two experiments designed to represent different injection scenarios: (A) low injection rate and strong capillary barrier and (B) high injection rate and weaker capillary barrier. Results show that ERT provided good estimates of the shape, size and location of the primary plume, but overestimated brine saturation within the plume and did not detect thin pathways of gas from the injection port or within the overlying capillary barrier. ERT measurements also indicated a change in saturation within the primary plume that corresponded with observed leakage through the capillary barrier in (B), demonstrating the potential utility of ERT as a leakage-monitoring tool. Repeated ERT scans during our experiments led to degradation in data quality that corresponded with an increase in measured contact resistance. Decreased data quality over time is clearly a concern for ERT implementation as a long-term monitoring strategy and deserves further study to quantify the responsible mechanisms. © 2012 Elsevier Ltd. Source

Discover hidden collaborations