Wellbore Cement Porosity Evolution in Response to Mineral Alteration during CO<sub>2</sub> Flooding [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2016.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 692-698 : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory, United States. Department of Energy. Office of Basic Energy Sciences, United States. Office of the Assistant Secretary of Energy for Fossil Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Mineral reactions during CO2 sequestration will change the pore-size distribution and pore surface characteristics, complicating permeability and storage security predictions. In this study, we report a small/wide angle scattering study of wellbore cement that has been exposed to carbon dioxide for three decades. We have constructed detailed contour maps that describe local porosity distributions and the mineralogy of the sample and relate these quantities to the carbon dioxide reaction front on the cement. We find that the initial bimodal distribution of pores in the cement, 1–2 and 10–20 nm, is affected differently during the course of carbonation reactions. Initial dissolution of cement phases occurs in the 10–20 nm pores and leads to the development of new pore spaces that are eventually sealed by CaCO3 precipitation, leading to a loss of gel and capillary nanopores, smoother pore surfaces, and reduced porosity. This suggests that during extensive carbonation of wellbore cement, the cement becomes less permeable because of carbonate mineral precipitation within the pore space. Additionally, the loss of gel and capillary nanoporosities will reduce the reactivity of cement with CO2 due to reactive surface area loss. Finally, this work demonstrates the importance of understanding not only changes in total porosity but also how the distribution of porosity evolves with reaction that affects permeability.
- Report Numbers:
- E 1.99:1338566
- Published through SciTech Connect.
Environmental Science and Technology 51 1 ISSN 0013-936X AM
Michael C. Cheshire; Andrew G. Stack; J. William Carey; Lawrence M. Anovitz; Timothy R. Prisk; Jan Ilavsky.
- Funding Information:
View MARC record | catkey: 23775598