Subterranean heaters
US5065818A · kind A · utility
339Cited by
16References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 7, 1991 |
| Grant date | Nov 19, 1991 |
| Priority date | — |
| Expiry date | Jan 7, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B36/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrical resistance subterranean heater is provided which is cemented directly in a well borehole without a casing in the borehole within the zone to be heated. The absence of the casing results in an economical installation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.