Downhole tubular milling apparatus, especially suitable for deployment on coiled tubing

A tubular milling assembly, comprising:

• a length of coiled tubing string disposed in a wellbore;
• a tubular milling apparatus attached to said coiled tubing string and positioned at a desired depth in said wellbore, said tubular milling apparatus comprising:
• a main body having a bore therein;
• a piston slidably disposed in said main body bore and movable between a first, upper position and a second, lower position;
• a plurality of operating arms movable between a first, retracted position when said piston is in said first, upper position and a second, extended position, when said piston is in said second, lower position;
• a plurality of cutter bases connected to said operating arms, and one or more cutters attached to each of said plurality of cutter bases;
• one or more link members connecting each of said plurality of cutter bases to said main body, whereby each of said plurality of cutter bases is maintained substantially parallel to said main body in each of said first and second positions;
• and
• a device for rotating the apparatus;
• wherein the apparatus is configured to be pulled upward by the coiled tubing string to mill in an uphole direction.

A method for milling tubulars in a wellbore, comprising the steps of:

• a) providing a tubular milling assembly comprising:
• a tubular milling apparatus comprising:
• a main body having a bore therein, the main body being configured for connection to a coiled tubing string;
• a piston slidably disposed in said main body bore and movable between a first, upper position and a second, lower position;
• a plurality of operating arms movable between a first, retracted position when said piston is in said first, upper position and a second, extended position, when said piston is in said second, lower position;
• a plurality of cutter bases connected to said operating arms, and one or more cutters attached to each of said plurality of cutter bases;
• and
• one or more link members connecting each of said plurality of cutter bases to said main body, whereby each of said plurality of cutter bases is maintained substantially parallel to said main body in each of said first and second positions;
• b) lowering said tubular milling assembly to a desired position in said wellbore, below a lower end of a tubular to be milled;
• c) pumping fluid through said coiled tubing string to move the piston to a second, lower position and thereby move the operating arms into a second, extended position;
• d) rotating the apparatus;
• and
• e) lifting said tubular milling apparatus by said coiled tubing string so as to engage said lower end of said tubular, and maintaining fluid flow and tension on said apparatus.