US 12,000,226 B2
Method and apparatus for milling a window in casing
Kenneth Maribu, Tananger (NO); John Gary Eller, Houston, TX (US); and Anthony Ryan, Houston, TX (US)
Assigned to CONOCOPHILLIPS COMPANY, Houston, TX (US)
Filed by CONOCOPHILLIPS COMPANY, Houston, TX (US)
Filed on Dec. 2, 2021, as Appl. No. 17/457,341.
Claims priority of provisional application 63/120,612, filed on Dec. 2, 2020.
Prior Publication US 2022/0170336 A1, Jun. 2, 2022
Int. Cl. E21B 29/06 (2006.01); E21B 29/04 (2006.01); E21B 29/12 (2006.01)
CPC E21B 29/06 (2013.01) [E21B 29/04 (2013.01); E21B 29/12 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of milling a window in a casing of an oil or gas well, the method comprising:
running a whipstock into the well;
running a first milling tool into the well to a milling site adjacent the whipstock using wireline, the first milling tool including a facility to grip the casing wherein the first milling tool comprises an extendable actuator arm on a distal end of which is a milling head, said arm having telescopic construction allowing it to extend and said arm also being mounted at its proximal end to the tool body via a linkage allowing the arm to be pivoted;
gripping the casing with the milling tool gripping facility, milling away a portion of casing material at the milling site wherein milling away the casing using the first milling tool includes extending the actuator arm such that the milling head of the first milling tool bears against the whipstock, causing the arm to pivot about its proximal end, and causing the milling head to be forced into engagement with the casing to mill away a portion of the casing material, and then withdrawing the first milling tool;
running a second milling tool into the well to the milling site, using coiled tubing or jointed drill pipe; and
using the second milling tool, milling away further material from the casing at the milling site until a window of a required dimension has been milled through the casing.