Long distance section mill for pipe in a borehole
US5014780A · kind A · utility
Inventor
Key dates
| Filing date | May 3, 1990 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | May 3, 2010 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/322
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A milling apparatus is disclosed. The structure includes first and second upper subs threading together and having an inner axial passage. A long stinger fits in this passage and connects with a mandrel which is telescoped within an outer tubular body for a vertical or telescoping movement. The mandrel is formed with lengthwise slots, enabling independent knives to be positioned in each of the slots. The knives are engaged for controlled radial deflection by a dovetail connection, and the slots terminate at a sloping shoulder to force the individual cutters radially outwardly. An expansion chamber below the mandrel forces the mandrel upwardly with respect to the surrounding outer tubular body, causing the cutters to extend through individual lengthwise slots in the outer tubular body to the cutting position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.