Abstract
Small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) have been used to study a carbonate rock from a deep saline aquifer that is a potential candidate as a storage reservoir for CO2 sequestration. A new methodology is developed for estimating the fraction of accessible and inaccessible pore volume using SANS/USANS measurements. This method does not require the achievement of zero average contrast for the calculation of accessible and inaccessible pore volume fraction. The scattering intensity at high Q increases with increasing CO2 pressure, in contrast with the low-Q behaviour where the intensity decreases with increasing pressure. Data treatment for high-Q scattering at different pressures of CO2 is also introduced to explain this anomalous behaviour. The analysis shows that a significant proportion of the pore system consists of micropores (<20 Å) and that the majority (80%) of these micropores remain inaccessible to CO2 at reservoir pressures. A new methodology has been developed to determine the fraction of open and closed porosity in rocks, without reaching the zero average contrast condition, using (ultra-)small-angle neutron scattering.
| Original language | English |
|---|---|
| Pages (from-to) | 2021-2030 |
| Number of pages | 10 |
| Journal | Journal of Applied Crystallography |
| Volume | 49 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 1 2016 |
Funding
The research at Oak Ridge National Laboratory's High Flux Isotope Reactor was sponsored by the Laboratory Directed Research and Development Program and the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy (DOE). The USANS measurements at the National Institute of Standards and Technology were supported in part by the National Science Foundation under agreement No. DMR-0944772. This work was partially supported by a subcontract to the Indiana Geological Survey from Battelle Memorial Institute under a DOE contract for the Midwest Regional Carbon Sequestration Partnership (MRCSP). TPB thanks the Central Analytical Research Facility and the Science and Engineering Faculty of the Queensland University of Technology for funding travel to ORNL and NIST. We dedicate this paper to the memory of Yuri Melnichenko, recognizing his achievements in the development of SANS techniques for investigating the petrophysical characteristics of earth materials.
| Funders | Funder number |
|---|---|
| Central Analytical Research Facility | |
| Midwest Regional Carbon Sequestration Partnership | |
| Scientific User Facilities Division | |
| National Science Foundation | DMR-0944772 |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| Battelle | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Laboratory Directed Research and Development | |
| Queensland University of Technology |
Keywords
- CO sequestration
- SANS
- USANS
- porosity
- rock
- small-angle X-ray scattering
- ultra-small-angle X-ray scattering
