Universal cementing plug
US6196311A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Oct 20, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A cementing plug having a universal construction and improved wiping and extended wear characteristics. The cementing plug has a plug subassembly with a body member and an elastomeric jacket on the body member. The body member defines a central opening therethrough with a shoulder therein. To configure the plug as a bottom cementing plug, a shearable insert is positioned on the shoulder, and to configure the plug as a top cementing plug, a non-shearable insert is positioned on the shoulder. The shearable insert is one of a plurality of such inserts designed to shear at correspondingly different shear pressures. In a first embodiment, the shearable insert is a substantially flat disk having a uniform thickness, and in a second embodiment, the shearable insert has an outer ring portion and a relatively thin inner domed portion. Thus, a bottom plug may be pumped down a well casing with cement and a top plug thereabove so that when the bottom plug lands at the bottom of the casing, the shearable insert will shear at the predetermined pressure. The jacket has one or more wiper cups which have a conical surface extending at an acute angle with respect to a longitudinal axis of the plug, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.