Apparatus and method for temporarily plugging a tubular
US5511617A · kind A · utility
Inventors
Key dates
| Filing date | Jun 29, 1995 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Jun 29, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/142
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus and method for controlling the pressure at which a fluid is introduced into a well penetrating a subterranean formation. The apparatus comprises a blow out sub having a sealed chamber between two plugs. The chamber is filled with a fluid at a known pressure. Thus, the pressure required to release the first plug is independent of the pressure in the well below the sub. The sub is attached to a tubular and positioned within the well. The first plug is then released upon application of a predetermined pressure fluid pressure, and the second plug is released upon application of a lesser pressure. The blow out sub may additionally comprise a tube forming a channel through the first plug, the chamber, and the second plug, with a means for controlling fluid flow through the channel. A first fluid may be introduced into the well via the channel prior to releasing the first plug.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.