Insights into the physical and chemical properties of a cement-polymer composite developed for geothermal wellbore applications
| Autor: | Barbara Kutchko, Mohamed Elbakhshwan, Wooyong Um, Roger Rousseau, Phillip K. Koech, Juergen Thieme, Simerjeet Gills, Tamas Varga, Timothy J. Roosendaal, Adriana M. Mckinney, Vassiliki Alexandra Glezakou, Kenton A. Rod, Jaehun Chun, Carlos Fernandez, Manh-Thuong Nguyen, Chonghang Zhao, Yu-chen Karen Chen-Wiegart, M. Ian Childers |
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| Rok vydání: | 2019 |
| Předmět: |
Cement
chemistry.chemical_classification Materials science Composite number 0211 other engineering and technologies 02 engineering and technology Building and Construction Polymer 021001 nanoscience & nanotechnology Retarder Microstructure chemistry 021105 building & construction Ultimate tensile strength General Materials Science Elasticity (economics) Composite material 0210 nano-technology Casing |
| Zdroj: | Cement and Concrete Composites. 97:279-287 |
| ISSN: | 0958-9465 |
| DOI: | 10.1016/j.cemconcomp.2018.12.022 |
| Popis: | To isolate injection and production zones from overlying formations and aquifers during geothermal operations, cement is placed in the annulus between well casing and the formation. However, wellbore cement eventually undergoes fractures due to chemical and physical stress with the resulting time and cost intensive production shutdowns and repairs. To address this difficult problem, a polymer-cement (composite) with self-healing properties was recently developed by our group. Short-term thermal stability tests demonstrated the potential of this material for its application in geothermal environments. In this work, the authors unveil some of the physical and chemical properties of the cement composite in an attempt to better understand its performance as compared to standard cement in the absence of the polymer. Among the properties studied include material's elemental distribution, mineral composition, internal microstructure, and tensile elasticity. Polymer-cement composites have relatively larger, though not interconnected, levels of void spaces compared to conventional cement. Most of these void spaces are filled with polymer. The composites also seem to have higher levels of uncured cement grains as the polymer seems to act as a retarder in the curing process. The presence of homogeneously-distributed more flexible polymer in the cement brings about 60–70% higher tensile elasticity to the composite material, as confirmed experimentally and by density-functional calculations. The improved tensile elasticity suggests that the composite materials can outperform conventional cement under mechanical stress. In addition, calculations indicate that the bonding interactions between the cement and polymer remain stable over the range of strain studied. The results suggest that this novel polymer-cement formulation could represent an important alternative to conventional cement for application in high-temperature subsurface settings. |
| Databáze: | OpenAIRE |
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