Whipstock starter mill assembly
US5431220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1994 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | Mar 24, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B29/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A starter mill adapted for use with a whipstock to mill a window through the casing of a well for deviating the direction of drilling. The starter mill includes a bearing nose which is utilized to indicate completion of the milling process. As the mill nears completion of the milling process, the bearing nose will become wedged between the whipstock face and the casing preventing further downhole movement. The bearing nose will engage whipstock and casing, allowing the work string to continue to rotate although the decreased torque resulting from the absence of milling provides a clear signal that the milling operation is complete. The cutters of the mill are spaced a predetermined distance from the bearing nose to ensure completion of the casing window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.