Window mill and drill bit
US7178609B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2004 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Feb 17, 2025 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B29/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for running a whipstock into a well bore attached to a combination mill and drill bit, releasing the mill/bit from the whipstock, milling a window in the casing, and drilling a lateral well bore, all in one trip. The mill/bit is provided with a primary cutting structure better suited for milling through the casing, and a secondary cutting structure, better suited for drilling through the earth formation. The secondary cutting structure is initially smaller in diameter than the primary cutting structure. The whipstock can be attached to the mill/bit with a shear bolt supported by a boss on the whipstock, with the boss designed to arrest axial motion of the mill/bit after shearing of the bolt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.