US 12,338,701 B2
In or relating to well abandonment and slot recovery
Alan Fairweather, Aberdeen (GB); James Linklater, Aberdeen (GB); and David Stewart, Aberdeen (GB)
Assigned to ARDYNE HOLDINGS LIMITED, Aberdeen (GB)
Appl. No. 18/571,225
Filed by Ardyne Holdings Limited, Aberdeen (GB)
PCT Filed Jul. 14, 2022, PCT No. PCT/EP2022/069719
§ 371(c)(1), (2) Date Dec. 16, 2023,
PCT Pub. No. WO2023/285588, PCT Pub. Date Jan. 19, 2023.
Claims priority of application No. 2110205 (GB), filed on Jul. 15, 2021; application No. 2203629 (GB), filed on Mar. 16, 2022; and application No. 2208461 (GB), filed on Jun. 9, 2022.
Prior Publication US 2024/0309718 A1, Sep. 19, 2024
Int. Cl. E21B 31/16 (2006.01); E21B 31/00 (2006.01); E21B 31/20 (2006.01); E21B 43/11 (2006.01)
CPC E21B 31/16 (2013.01) [E21B 31/005 (2013.01); E21B 31/20 (2013.01); E21B 43/11 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method of removing casing from a well, in which an annulus between the outside of the casing and the inside of a surrounding downhole body is at least partially filled by debris, comprising steps:
(a) determining a casing cutting target depth (CCTD) to provide a section of casing for removal;
(b) cutting the casing at the casing cutting target depth (CCTD);
(c) perforating the section of casing for removal by providing a plurality of perforations along a perforation length thereof;
(d) washing the annulus along a first length of the section of casing for removal, so as to clear at least a portion of the debris from the annulus,
wherein the first length is shorter than, and located along, the perforation length,
wherein washing the annulus along said first length comprises passing fluid through the one or more perforations in the casing provided in said first length;
(e) gripping the section of casing;
(f) pulling the section of casing; and
(g) in the event that the section of casing is free, pulling the section of casing from the well,
wherein, in the event that the section of casing is not free, the method includes selecting a second length of the section of casing for removal and repeating the steps (d) to (g) on the second length,
wherein the second length is shorter than, and located along, the perforation length, and
wherein the first length and the second length are different lengths of the section of casing for removal located along the perforation length.