Oilfield tubular shear ram and method for blowout prevention
US5400857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1993 |
| Grant date | Mar 28, 1995 |
| Priority date | — |
| Expiry date | Dec 8, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S285/922
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A ram assembly for positioning within a through bore of a blowout preventer body includes first and second opposing ram pistons each powering a respective knife blade. Each knife blade may have a pair of angled shear edges on opposite sides of the respective ram centerline, with each pair of angled shear edges defining a generally V-shaped configuration. The pair of opposing knife edges preferably engage the oilfield tubular at four contact points spaced substantially equidistant about a circumference of the tubular, and thereby contain the tubular for the shearing operation. According to the method of the present invention, the oilfield tubular is sheared substantially by brittle shearing rather than ductile shearing. By containing the tubular prior to shearing, the body of a shearing assembly may have a bore only slightly greater than the diameter of tubular to be sheared, thereby significantly reducing the costs and increasing the versatility of the shearing equipment, and also reducing the cost of the blowout preventer and the associated wellhead stack.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.