Multi-functional additive for use in well cementing
US6235809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1998 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Sep 29, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/493
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to a cement composition for cementing oil, gas and geothermal wells comprising: a cement; and an additive comprising a blend of a sodium silicate; water; a carrageenan suspending agent; a sodium polyacrylate; an AMPS terpolymer; a dispersant; and a cellulosic water soluble polymer. The dispersant may comprise a sulfonated naphthalene formaldehyde condensate or a sulfonated ketone acetone formaldehyde condensate. The cellulosic water soluble polymer may comprise HEC or CMHEC. The invention can also function to reduce the occurrence of gas channelling and stabilize foam created by adding nitrogen gas to cement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.