Resistivity measurement system for drilling with casing
US5168942A · kind A · utility
172Cited by
9References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 21, 1991 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Oct 21, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for measuring earth formation resistivity while drilling a wellbore through an earth formation using a self-contained drilling assembly supported at the lower end of a casing string. The drilling assembly includes a drilling fluid driven motor driving a drill bit, where the motor and bit are electrically isolated from the casing string. Formation resistivity measuring circuitry is provided in the assembly. Data transmission mechanism is provided for encoding the resistivity data and transmitting it through the drilling fluid to the surface location of the wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.