Distributed acoustic sensing for coiled tubing characteristics

A wellbore monitoring system, comprising:

• a tubular conveyance extending into a wellbore;
• a signal cable extending along a length of the tubular conveyance within the wellbore;
• a distributed acoustic sensing unit operably coupled to the signal cable for acquiring downhole distributed acoustic sensing measurements from the signal cable;
• a processor operably coupled to the distributed acoustic sensing unit for processing the distributed acoustic sensing measurements;
• and
• a memory operably coupled to the acoustic sensing unit, the memory having a set of instructions stored thereon that, when executed by the processor cause the processor to compare the processed distributed acoustic sensing measurements to a predetermined acoustic signature of a downhole event within the tubular conveyance.

A method for monitoring a downhole operation, the method comprising:

• deploying a signal cable into a wellbore on a tubular conveyance, wherein the signal cable extends along a length of the tubular conveyance;
• dropping an actuator through an interior passageway of the tubular conveyance into the wellbore;
• acquiring downhole distributed acoustic sensing measurements from the signal cable;
• detecting, in the distributed acoustic sensing measurements, an acoustic signature of the actuator moving through the tubular conveyance, wherein the acoustic signature includes a dual peak pattern indicative of relatively high levels of acoustic energy at leading and trailing ends of the actuator.