Drawworks system

Abstract

An example drawworks may include an electrical drive motor and an output shaft driven by the electrical drive motor. A worm gear may be coupled to the output shaft and a bull gear may be engaged with the worm gear. A wireline drum may be coupled to the bull gear and receive rotation from the electrical drive motor through the bull gear. The electrical drive motor, worm gear, and bull gear may comprise a drive unit that is removably coupled to the wireline drum. The wireline drum may form a drum unit with at least one spigot coupled to the drum, which may be removable coupled to the drive unit.

What is claimed is: 
     
         1 . A drawworks comprising:
 an electrical drive motor;   a worm gear coupled to the electrical drive motor;   a bull gear engaged with the worm gear; and   a wireline drum coupled to the bull gear.   
     
     
         2 . The drawworks of  claim 1  further comprising a second electrical drive motor. 
     
     
         3 . The drawworks of  claim 2  wherein the electrical drive motor and the second electrical drive motor employ digital gearing. 
     
     
         4 . The drawworks of  claim 2  wherein the second electrical drive motor is coupled to a second worm gear. 
     
     
         5 . The drawworks of  claim 4  wherein the second worm gear is engaged with the bull gear. 
     
     
         6 . The drawworks of  claim 5 , wherein the electrical drive motor and the second electrical drive motor are positioned on opposite sides of the wireline drum. 
     
     
         7 . The drawworks of  claim 4  wherein the second worm gear is engaged with a second bull gear coupled to the wireline drum. 
     
     
         8 . The drawworks of  claim 1  further comprising a brake module coupled to the wireline drum. 
     
     
         9 . The drawworks of  claim 8 , wherein the brake module comprises a brake rotor, one or more brake calipers, and a mechanical spring for engaging the one or more brake calipers with the brake rotor. 
     
     
         10 . The drawworks of  claim 1  wherein the electrical drive input motor can be locked in position via electrical control. 
     
     
         11 . The drawworks of  claim 1  wherein the electrical drive motor is a variable frequency drive motor. 
     
     
         12 . The drawworks of  claim 1  wherein the electrical drive motor is coupled to the worm gear through a pinion gearbox. 
     
     
         13 . A drawworks assembly comprising:
 a drive unit comprising one or more drive motors coupled to a worm gear;   a drum unit removably coupled to the drive unit and comprising a wireline drum configured to receive rotational movement from the worm gear;   one or more pedestal bearing units supporting and removably coupled to the drum unit.   
     
     
         14 . The drawworks assembly of  claim 13 , wherein the drum unit further comprises one or more drive spigots. 
     
     
         15 . The drawworks assembly of  claim 14 , wherein the one or more pedestal bearing units engage with the one or more drive spigots to provide rotation to the drum unit. 
     
     
         16 . The drawworks assembly of  claim 13 , wherein the one or more drive motors comprises one or more drive motor modules removably coupled to the worm gear. 
     
     
         17 . The drawworks assembly of  claim 16 , wherein the one or more electrical drive motor modules produces a combined horsepower rating chosen based on a load requirement 
     
     
         18 . The drawworks assembly of  claim 13 , wherein the worm gear is positioned within a worm gearbox of the drive unit, the worm gearbox removably coupled to the one or more drive motors and the drum unit. 
     
     
         19 . A method for controlling a wireline in a drilling operation, comprising
 rotating a worm gear using an electric drive motor coupled to the worm gear;   receiving the rotation of the worm gear at a bull gear engaged with the worm gear; and   transmitting the rotation of the worm gear from the bull gear to a wireline drum coupled to the bull gear.   
     
     
         20 . The method of  claim 19 , wherein rotating the worm gear using the electric drive motor coupled to the worm gear comprises rotating the worm gear using a pinion gearbox between the electric drive motor and the worm gear