公开(公告)号：US20170241225A1

公开(公告)日：2017-08-24

申请号：US15513048

申请日：2015-09-17

Applicant: STATOIL PETROLEUM AS

Inventor： Gjermund GRIMSBO ,  Marcus FATHI ,  Torgeir WENN ,  Pål Viggo HEMMINGSEN ,  Astrid BJØRGUM

IPC: E21B29/02 ,  E21B47/00 ,  E21B33/12 ,  E21B33/13

CPC classification number: E21B29/02 ,  E21B33/12 ,  E21B33/13 ,  E21B47/00

Abstract: There is provided a method for removing iron-containing casing from a well bore comprising providing a cathode in said well bore, wherein said cathode is connected to the negative pole of a power source; connecting said iron-containing casing to the positive pole of said power source; injecting an electrolyte into said well bore, wherein said electrolyte contacts said iron-containing casing and said cathode; applying a current so that the iron in said iron-containing casing is oxidised to iron cations; allowing said iron cations to dissolve in said electrolyte; and removing said electrolyte from said well bore. Also provided are a system for removing iron-containing casing from a well bore, a method for monitoring the removal of an iron-containing casing from a well bore and a method for plugging and abandoning a well.