Fluid loss control in oil field cements
US4480693A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1983 |
| Grant date | Nov 6, 1984 |
| Priority date | — |
| Expiry date | Dec 23, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2103/46
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to materials which reduce the filtration of fluid into permeable earth formations during cementing processes in the drilling and completing of subterranean wells, particularly wells for the recovery of petroleum resources. Petroleum well cementing is the process of mixing a slurry of cement, water, and other additives and pumping it down through steel casing to critical points in the oil well annulus around the casing or in the open hole below the casing string. The primary functions of the cementing process are to restrict fluid movement between geological formations and to bond and support the casing. In addition the cement aids in protecting the casing from corrosion, preventing blowouts by quickly sealing formations, protecting the casing from shock loads in drilling deeper wells, and sealing off lost circulation or thief zones. A common problem in petroleum well cementing is the flow of liquid from the cement slurry into porous earth formations in contact with the cement. This fluid loss is undesirable since it can result in dehydration of the cement slurry, and it causes thick filter cakes of cement solids which can plug the well bore. The fluid …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.