Abstract: A method of sealing a partly or entirely annulus-cemented casing portion of a first casing in a second casing in a petroleum well, includes running a drill pipe string-conveyed perforating gun with a cement shattering device into said well; positioning said perforating gun at said cemented casing portion and activating first, shallow-perforating charges to make first, shallow perforations through said casing portion into thus making a perforated, cement-filled annulus portion and leaving said second casing intact; activating said cement shattering device to disintegrate all or part of said cement within said first perforated annulus portion; running a washing tool along said perforated casing portion, washing out said shattered cement from said perforated annulus portion. The washed-out casing portion may then be cut using a cutter tool and pulled out of hole, or cemented using a cementing tool, or a combination thereof.

Abstract: A drill pipe string conveyed retrievable plug system has a central through bore. The plug system includes a drill pipe string; a control section; a running tool with a connector at a lower end of a drill pipe string with the control section, and a top connector on a mechanical plug section with a bridge plug. The mechanical plug section includes a mandrel with the through bore, a ball valve arranged for closing the through bore, and a packer sleeve on the mandrel with slips and a packer element. The control section includes an electric supply, an electric control unit, and sensors connected to the electric control unit. The mechanical plug section includes a motor controlled by the electrical control unit. The motor is arranged to turn a selector ring to a selected first rotational position so as for allowing a piston sleeve to slide to an axial first stop position in order for opening to fluid channels through the mandrel from the through bore to the packer sleeve.

Abstract: A drill pipe string conveyed retrievable plug system has a central through bore. The plug system includes a drill pipe string; a control section; a running tool with a connector at a lower end of a drill pipe string with the control section, and a top connector on a mechanical plug section with a bridge plug. The mechanical plug section includes a mandrel with the through bore, a ball valve arranged for closing the through bore, and a packer sleeve on the mandrel with slips and a packer element. The control section includes an electric supply, an electric control unit, and sensors connected to the electric control unit. The mechanical plug section includes a motor controlled by the electrical control unit. The motor is arranged to turn a selector ring to a selected first rotational position so as for allowing a piston sleeve to slide to an axial first stop position in order for opening to fluid channels through the mandrel from the through bore to the packer sleeve.