Structural and chemical changes from CO2 exposure to self-healing polymer cement composites for geothermal wellbores

Journal Article · Fri Jan 01 00:00:00 EST 2021 · Geothermics

DOI:https://doi.org/10.1016/j.geothermics.2020.101932· OSTI ID:1681213

Elbakhshwan, Mohamed ^[1]; Gill, Simerjeet ^[1]; Rod, Kenton A.  ^[2]; Bingham, Emma B. ^[3]; McKinney, Adriana L. ^[3]; Huerta, Nicolas J.  ^[3]; Lopano, Christina ^[4]; Kutchko, Barbara ^[5]; Chen-Wiegart, Yu-Chen Karen ^[6]; Zhao, Chonghang ^[6]; Williams, Garth J. ^[7]; Thieme, Juergen ^[8]; Varga, Tamas  ^[3]; Ecker, Lynne ^[9]; Fernandez, Carlos A.  ^[3]

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1. Brookhaven National Laboratory
2. DEPT OF ECOLOGY
3. BATTELLE (PACIFIC NW LAB)
4. NETL
5. National Renewable Energy Laboratory
6. State University of New York at Stony Brook
7. SLAC National Accelerator Center
8. BROOKHAVEN NATIONAL LAB
9. BNL

Wellbore cement is subjected to a number of mechanical, thermal and chemical stress regimes over its lifetime. Therefore, next generation wellbore cement formulations need to be evaluated in conditions relevant to these environments. In this work, we investigate the mechanism of the alteration of a novel self-healing polymer-cement composite recently reported by our group after exposure to a CO2-rich environment by using synchrotron based X-ray Fluorescence (XRF) and X-ray absorption near edge structure (XANES) and scanning electron microscopy coupled with energy dispersive spectroscopy. Results showed that chemical alteration of the polymer-cement follows the rim carbonation mechanism, similar to conventional cement although carbonation takes place to a lesser extent in polymer-cements despite the higher porosity. Along with detailed mechanistic insights on carbonation in polymer-cement composite, the performance of these in CO2-rich environment is further studied using standard compressive strength analysis.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1681213
• Report Number(s): PNNL-SA-155591
• Journal Information: Geothermics, Vol. 89; ISSN 0375-6505
• Publisher: Elsevier
• Country of Publication: United States
• Language: English