Selective zonal isolation of oil wells
US5697441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1996 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Mar 20, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/261
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In the horizontal parts of deviated wells arranged within a producing formation, good communication between the formation and the wellbore liner is required, and this may be achieved by using a slotted or perforated liner in the horizontal section without any cementing to bond the liner to the wellbore. However, problems can arise if it is desired to work selectively in a zone in the horizontal section, since with a perforate liner there is no way of isolating the zone from the remainder of the well by using internal packers. This problem can be overcome by providing packers around the outside of the liner, this then allows packers inside the liner to be used to isolate a portion of the well. However, these external casing packers must be sealed against the wellbore, they must be positioned in advance, and they substantially increase the cost of the completion. The present invention suggests novel means of zonal isolation in a well with a perforate liner, this isolation being achieved by using a liquid composition that can be pumped into the relevant annular region between the liner and the wellbore and then set to form a plug that prevents communication from one side to the other …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.