Well-Set has filed a patent application covering a novel technique to suspend cement in a casing-by-casing annulus (eliminating gravitational migration/slump). This will potentially allow cross-wellbore cement plugs to be set using rig-less techniques without having to cut & pull casing strings.
This technique uses magnetorheological (MR) cement to form an effective barrier in an annular space. The MR cement is suspended between two magnetic fields until the cement sets, meaning that there is no scope for gravitational slump.
This technique allows casing annuli to be effectively plugged between defined depths using rig-less techniques (wireline or coiled tubing). This allows for a robust ‘cross-sectional’ abandonment barrier to be created in the wellbore, without having to cut & pull casing.
Various verification methods are available to confirm that the annular barrier plug has been correctly placed, and is effective.