A workover rig is a specialized piece of equipment used in the oil and gas industry for maintenance, repair, and enhancement operations on existing oil or gas wells. It is deployed to perform various wellbore interventions and workover activities to improve or restore the production and functionality of the well.
Here are some key features and functions of a workover rig:
Wellbore Interventions: A workover rig is designed to perform a range of interventions in the wellbore, including cleaning, completion, stimulation, remediation, and production enhancement activities. These interventions aim to address issues such as wellbore damage, equipment malfunction, declining production rates, or changing reservoir conditions.
Hoisting System: Workover rigs are equipped with a hoisting system, typically consisting of a mast or derrick, drawworks, and a drilling line or wire rope. This system allows for the lifting and lowering of equipment and tools into the wellbore during the workover operations.
BOP Stack: Workover rigs are fitted with a workover blowout preventer (BOP) stack, which is a set of valves and control equipment designed to provide well control and prevent blowouts during intervention operations. The BOP stack helps ensure the safety and integrity of the wellbore during workover activities.
Well Control Equipment: Workover rigs are equipped with well control equipment, including choke manifold, kill manifold, and hydraulic control systems. These components enable the control and management of wellbore pressure and the circulation of fluids during workover operations.
Specialized Tools and Equipment: Workover rigs utilize a variety of specialized tools and equipment for specific intervention tasks. These may include slickline units for well logging and mechanical operations, coiled tubing units for interventions in live wells, snubbing units for pressure control during wellbore operations, and wireline units for well intervention and data acquisition.
Compact Design: Workover rigs are often designed to be more compact and mobile compared to drilling rigs. They can be truck-mounted or skid-mounted, allowing for easier transportation and faster rig-up times, especially for wellbore interventions in remote or challenging locations.
Workover rigs play a vital role in maintaining and optimizing the production and functionality of existing oil and gas wells. They are deployed when wells require intervention or when production declines, equipment needs repair or replacement, or when modifications are needed to enhance production or access different zones within the reservoir.
It's important to note that workover operations require skilled personnel, proper planning, and adherence to safety protocols to ensure successful and safe wellbore interventions.