Patent ID: 9745814
Date: 2017-08-29
CPC Classifications: E21B

Claim:
1. A method for milling an opening into a tubular positioned in a well bore with coiled tubing, comprising: utilizing a string of coiled tubing; utilizing a milling tool mounted on said string of coiled tubing; utilizing an injector motor operable to control an injector for lowering and raising said string of coiled tubing into and out of said well bore; utilizing an encoder which produces pulses indicative of movement of said string of coiled tubing of coiled tubing into and out of said well bore; utilizing a tension sensor for said coiled tubing for use in determining a weight on said milling tool during milling; and utilizing a controller programmed for controlling said injector motor, said controller being operably connected to said tension sensor and said encoder, said controller being programmed to control said injector motor so that said encoder produces less than a predetermined maximum number of pulses for a given time interval, wherein said controller is programmed to control said injector motor to maintain said selected weight unless said encoder produces more than said predetermined maximum number of pulses for said given time period whereupon said controller operates said injector motor to limit or stop lowering of said coiled tubing into said well bore.