Detecting and reducing bit whirl
US5864058A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 25, 1997 |
| Grant date | Jan 26, 1999 |
| Priority date | — |
| Expiry date | Jun 25, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A downhole sensor sub is provided in the lower end of a drillstring, such sub having three orthogonally positioned accelerometers for measuring vibration of a drilling component such as the drill bit and/or the bottom hole assembly (BHA) along the X, Y and Z axes. The lateral acceleration is measured along either the X or Y axis and then analyzed in the frequency domain as to peak frequency and magnitude at such peak frequency. Backward whirling of the drilling component is indicated when the magnitude at the peak frequency exceeds a predetermined value. A low whirling frequency accompanied by a high acceleration magnitude based on empirically established values is associated with destructive vibration of the drilling component. One or more drilling parameters (weight on bit, rotary speed, etc.) is then altered to reduce or eliminate such destructive vibration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.