Non-rotating sensor assembly for measurement-while-drilling applications
US6247542A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1999 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Feb 9, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/22
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An MWD method and apparatus for determining parameters of interest in a formation has a sensor assembly mounted on a slidable sleeve slidably coupled to a longitudinal member, such as a section of drill pipe. When the sensor assembly is held in a non-rotating position, for instance for obtaining the measurements, the longitudinal member is free to rotate and continue drilling the borehole, wherein downhole measurements can be obtained with substantially no sensor movement or vibration. This is particularly useful in making NMR measurements due to their susceptibility to errors due caused by tool vibration. In addition, the substantially non-rotating arrangement of sensors makes it possible to efficiently carry out VSPs, reverse VSPs and looking ahead of the drill bit. A clamping device is used, for instance, to hold the sensor assembly is held in the non-rotating position. The sensor assembly of the present invention can include any of a variety of sensors and/or transmitters for determining a plurality of parameters of interest including, for example, nuclear magnetic resonance measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.