Method for Zone Isolation in a Subterranean Well

A method for zone isolation in a subterranean well, the well being provided with a pipe body, at least in a portion, the method comprising:

• (A) providing a plug over a longitudinal section of the well, the plug covering substantially the entire cross section of the well at least in a portion of the longitudinal section, so that the plug fills the inside of the pipe body and an annulus between the outside of the pipe body and a surrounding well body, wherein (A) comprises:
• (A1) lowering a perforation tool into the pipe body to the longitudinal section where the plug is to be set:
• (A2) forming perforations the pipe body along the longitudinal section the perforation tool;
• (A3) with a washing tool which is attached to a string allowing through-flow and which is lowered to the longitudinal section L1, pumping a washing fluid down the string and out into the pipe body via the washing tool;
• (A4) with a directional-control means connected to the washing tool, directing the washing fluid into the annulus between the outside of the pipe body and the surrounding well body;
• and
• (A5) pumping a fluidized plugging material down the string and out into the pipe body, and thereby also into the annulus the perforations in the pipe body.