Freeing a downhole seal in a wellbore

A method for freeing a stuck seal assembly in a wellbore, comprising:

• running a downhole tool on a downhole conveyance through the wellbore formed from a terranean surface into a subterranean formation, the downhole tool comprising:
• a piston sub-assembly coupled with the top sub-assembly and comprising a plurality of pistons;
• a cutting sub-assembly coupled with the top sub-assembly and the piston sub-assembly and comprising at least one cutting blade;
• and
• a motor assembly coupled with the piston sub-assembly and the cutting sub-assembly, the motor assembly comprising a motor;
• operating the motor to supply power to the piston sub-assembly to move the plurality of pistons to contact a portion of a seal assembly installed in the wellbore to generate mechanical vibrations to jar the seal assembly from being stuck in the wellbore;
• and
• operating the motor to supply electrical power to the cutting sub-assembly to rotate the at least one cutting blade to cut through a portion of a production tubing adjacent the seal assembly.

A downhole tool, comprising:

• a top sub-assembly configured to couple to a downhole conveyance that is operable to run the downhole tool into a wellbore formed from a terranean surface into a subterranean formation, the downhole conveyance comprising a tubular working string that comprises a multicycle valve installed uphole of the top sub-assembly;
• a piston sub-assembly coupled with the top sub-assembly and comprising a plurality of pistons configured to moveably contact a portion of a seal assembly installed in the wellbore to generate mechanical vibrations to jar the seal assembly from being stuck in the wellbore;
• a cutting sub-assembly coupled with the top sub-assembly and the piston sub-assembly and comprising at least one cutting blade configured to moveably cut through a portion of a production tubing adjacent the seal assembly;
• and
• a motor assembly coupled with the piston sub-assembly and the cutting sub-assembly, the motor assembly comprising a hydraulic motor configured to operate with a flow of a wellbore fluid supplied through the tubular working string to operate the piston sub-assembly and generate electrical power to the cutting sub-assembly supply, the multicycle valve configured to operate the hydraulic motor in a plurality of operating modes based on one or more characteristics of the flow of the wellbore fluid, wherein:
• in a first operating mode, the hydraulic motor is configured to operate the piston sub-assembly with the flow of the wellbore fluid;
• and
• in a second operating mode, the hydraulic motor is configured to generate electrical power to the cutting sub-assembly with the flow of the wellbore fluid.