A METHOD OF ESTABLISHING A CEMENT PLUG IN AN ANNULAR REGION BETWEEN A FIRST AND A SECOND CASING

摘要

A method of establishing a cement plug (3) in an annular region (35) between a first casing (100) and a second casing (200) in a well characterised in that the method comprises the steps of: - perforating the first casing (100) to open a flow path to the annular region (35); - providing a magnetorheological cementitious slurry (7); - inducing a magnetic field for affecting the physical properties of the magnetorheological cementitious slurry (7) and for defining a lower boundary for the cement plug (3); - feeding the magnetorheological cementitious slurry (7) into the annular region (35) through a perforation (111) in the first casing (100); and - impeding the mobility of the magnetorheological cementitious slurry (7) in the annular region (35) by exposing it to the magnetic field such that the magnetorheological cementitious slurry (7) may consolidate substantially at the lower boundary without the need for a base device (2) in the annular region (35). The disclosure further relates to a cement plug (3) substantially filling an annular region (35) between a first casing (100) and a second casing (200), a well comprising the cement plug (3), and a system for setting the cement plug (3).