Retarding systems and application to oil well cementing
US6511537B1 · kind B1 · utility
15Cited by
9References
20Claims
0Family size
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Key dates
| Filing date | Oct 20, 2000 |
| Grant date | Jan 28, 2003 |
| Priority date | — |
| Expiry date | Oct 20, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2103/22
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Systems for retarding setting in an oilfield well cement slurry comprise a solution of a phosphonate selected from methylene phosphonic acid derivatives and a phosphate, in particular selected from the following salts or the corresponding acids: mono-phosphates (ortho-phosphates PO42; meta-phosphates PO3), acyclic poly-phosphates (pyrophosphates P2O74, tripolyphosphates P3O105) or cyclic poly-phosphates. The system preferably may also comprise a retarder booster and is more particularly applicable to cementing at low or medium temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.