Patent ID: 8091640

Claim:
A device for cementing a well or a pipe having a wall, for example a casing, having a portion to be cemented, which device comprises an assembly which is designed to be introduced into the well or pipe and to be positioned opposite the portion to be cemented, the assembly comprising a tubular mandrel and an inflatable tubular membrane having end zones, the inflatable tubular membrane surrounding said mandrel, the inflatable tubular membrane having a wall made of a flexible and elastic material which expands radially under the effect of an internal pressure, the end zones of said inflatable tubular membrane being able to dilate radially upon introduction of a pressurized fluid into said inflatable tubular membrane in order to form annular beads which are applied firmly against the wall of the well or pipe, on either side of the portion to be cemented, and a median zone located between the end zones of said inflatable tubular membrane also dilates radially, but with a lesser amplitude, to form an annular space between the median zone and the portion of wall to be cemented, the device additionally comprising orifices for injecting a curable liquid cement into the annular space while the inflatable tubular membrane is kept inflated and for deflating said inflatable tubular membrane once the cement has set, wherein said inflatable tubular membrane is secured to said mandrel by an annular anchoring part which is radially non-extendable and is located within said median zone, wherein end zones of said annular anchoring part are fixed to movable rings, which are guided in translation in a sealed manner on the mandrel to slide axially on the mandrel as a result of the inflation or deflation of said inflatable tubular membrane.