What is a Workover Rig?
Workover rigs are mobile units used for maintenance and repair of oil wells. Their primary function is to perform a variety of tasks on existing wells, such as repairing, cleaning, or replacing equipment that helps extract oil or gas. While drilling rigs are responsible for drilling new wells, workover rigs come into play when maintenance is required on an existing well.
Functions of a Workover Rig
- Well Maintenance: Ensuring that wells are operating efficiently by replacing damaged components, such as pumps or valves.
- Well Stimulation: This process enhances the flow of oil or gas from a well. It includes tasks like hydraulic fracturing (fracking) or acidizing.
- Workover Operations: Tasks that include re-entering and performing necessary operations in a well to restore production levels, such as cleaning, repairing, or even re-drilling a section of the well.
Components of a Workover Rig
A workover rig consists of several important components :
- Power system: for equipment operation. Including: diesel engine, electric engine.
- Transmission system: transfer the power to each part. Including: Torque converter, drive shaft, clutch.
- Rotary system: provides twisting force to drive downhole tool rotation. Including: turntable, faucet, downhole tools, drill rigs, etc.
- Circulation system: Through the mud pump, the mud is pumped down the hole to the bottom of the hole, and then returned from the annulus to achieve circulation, carry cuttings, or achieve well killing operations.
- Load lifting system: suspension and lifting of the well string. Including: derrick, winch, wire rope, crane, tour car, hook, hanging ring.
- Chassis system: Supports the devices of other systems.
- Blowout prevention system: prevent and deal with blowout. Including: all kinds of blowout preventer, energy storage, kill manifold, choke manifold, kill blowout preventer pipeline, etc.
Why is Workover Important?
Workover operations are critical for the longevity and efficiency of oil wells. Oilfields can last for decades, but regular maintenance is needed to keep them productive. Workover rigs ensure that wells remain productive even when parts of the well start to fail or lose efficiency.
Workover vs. Drilling Rig
A drilling rig is used to create a new well, while a workover rig focuses on the maintenance of an existing one. The tasks, equipment, and operational processes are different, but both types of rigs play a crucial role in oil extraction.
