Patent ID: 7373983

Claim:
A method for forming an opening in the housing of a tubing-retrievable subsurface safety valve, the safety valve comprising a pressure containing body having an inner surface and a bore therethrough, the method comprising: running a milling tool into a wellbore, the wellbore having a string of production tubing therein, and the production tubing having the tubing-retrievable subsurface safety valve in series therein, the milling tool comprising: an elongated housing system, at least a portion of the housing system being dimensioned to be received within the bore of the pressure containing body of the tubing-retrievable subsurface safety valve; a cutting system having at least one blade; a drive system configured to rotate the at least one blade in the cutting system, the drive assembly residing within the housing system; and an actuating system for actuating the drive assembly, the actuating system also residing within the housing system; landing the milling tool into the bore of the pressure containing body of the tubing-retrievable subsurface safety valve; initiating the actuating system so as to actuate the drive system and cause the at least one blade to rotate, thereby forming an opening in the pressure containing body; and removing the milling tool from the wellbore.