Mullite microsphere-filled lightweight calcium phosphate cement slurries for geothermal wells: Setting and properties
✍ Scribed by T. Sugama; N.R. Carciello; T.M. Nayberg; Unocal; L.E. Brothers
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 398 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0008-8846
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✦ Synopsis
The chemical factors affecting the setting properties of microsphere-filled lightweight calcium phosphate cement (LCPC) slurries, ranging in density from1.32 to 1.12 g/cc, athighhydrothermal temperature were investigated.
The LCPC slurries consisted of calcium aluminate cement (CAC) as the base reactant, a -(-NaPO,-)-, solution as the acid reactant, and mullite-shelled hollow microspheres as the lightweight additive. Two major aspects were studied; one was the importance of the chemical constituents of CAC, and the other was the rate of the hydrothermal reaction between the mullite shell and the Na ions dissociated from -(-NaPO,-)-,. For the former, the use of CAC having C,AS and CA phases as the major chemical components shortened the thickening time of LCPC slurries, whereas CACs with CA, CA,, and cu-Al,O, phase components extended the thickening time. For the hydrothermal reaction, an excess of zeolite X type formed by the uptake of Na by mullite microspheres reduced the thickening time.