Or relating to well abandonment and slot recovery
US11466530B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2018 |
| Grant date | Oct 11, 2022 |
| Priority date | — |
| Expiry date | Dec 16, 2038 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for casing recovery for well abandonment. A string is run-in, the string including a hydraulic jack (18), an anchor (28), a casing spear (20), a downhole flow pulsing device (22) and a pressure drop sub (24). The casing spear grips an upper end of the length of casing to be pulled. The anchor is set in casing of a greater diameter above the length of cut casing. Fluid pumped through the string and through the pressure drop sub will increase fluid pressure at the hydraulic jack to a first fluid pressure (78). Fluid pumped through the downhole flow pulsing device will vary the fluid flow superimposing a cyclic pressure (82) on the first pressure (78), causing oscillation of an inner mandrel (30) of the hydraulic jack. The jack moves the oscillating inner mandrel upwards relative to the anchor to pull the length of casing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.