Well casing window mill
US4266621A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 14, 1978 |
| Grant date | May 12, 1981 |
| Priority date | — |
| Expiry date | Aug 14, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B29/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A diamond milling cutter for elongating a laterally opening window in a well casing set in a well bore extending into the earth. The mill has a revolving surface which engages a sidetracking whipstock or the edge of the casing being milled to urge the mill off dead center on the casing edge and enhance the cutting action. One or more eccentric lobes engage the whipstock and cause the mill to revolve on a gyrating or non-fixed axis and effect oscillation of the cutter center laterally of the edge, or a broadly conical nose on the cutting face of the mill provides a wedge action against the casing to laterally move the mill off center and enhance the cutting action.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.