US 12,392,217 B2
Toolstring and method for inner casing perforating, shattering annulus cement, and washing the first annulus in a second casing
Jarle Varhaug, Ålgård (NO); Andreas Fliss, Stavanger (NO); and Bjørn Tore Torvestad, Stavanger (NO)
Assigned to ARCHER OILTOOLS AS, Stavanger (NO)
Appl. No. 18/290,411
Filed by Archer Oiltools AS, Stavanger (NO)
PCT Filed May 11, 2022, PCT No. PCT/NO2022/050105
§ 371(c)(1), (2) Date Nov. 13, 2023,
PCT Pub. No. WO2022/240295, PCT Pub. Date Nov. 17, 2022.
Claims priority of application No. 20210594 (NO), filed on May 11, 2021.
Prior Publication US 2024/0247564 A1, Jul. 25, 2024
Int. Cl. E21B 37/00 (2006.01); E21B 33/13 (2006.01); E21B 33/14 (2006.01); E21B 43/11 (2006.01); E21B 43/117 (2006.01); E21B 43/1185 (2006.01); E21B 43/119 (2006.01)
CPC E21B 33/14 (2013.01) [E21B 33/13 (2013.01); E21B 37/00 (2013.01); E21B 43/117 (2013.01); E21B 43/1185 (2013.01); E21B 43/1193 (2020.05)] 37 Claims
OG exemplary drawing
 
24. A casing annulus cleaning tool string comprising:
a drill pipe string with:
a conveyed perforation gun; and
a cement shattering device,
wherein both the perforation gun and the cement shattering device are arranged near said drill pipe string's lower end, for being lowered into a casing with an annulus cemented casing portion about said casing in a petroleum well,
wherein said perforating gun is arranged with:
first, shallow-perforating charges for shooting first, shallow perforations through said casing portion into a first annulus, said shallow-perforating charges arranged for leaving a surrounding second casing intact;
wherein said shattering device is arranged for being activated after said shallow-perforating charges to provide combustion energy through said shallow perforations to disintegrate all or part of said cement within said first perforated annulus, and
wherein a washing tool is arranged above said perforation gun and cement shattering device on said drill pipe string, said washing tool for washing out said shattered cement from said annulus.