Hydraulic Well Workover

Hydraulic Well Workover: A Snubbing Job for Non-Killing Operations

Technical Term: Hydraulic Well Workover

Summary Description: A hydraulic well workover is a specialized workover technique employed to perform operations on a well without the need to kill the well with drilling fluid. This method utilizes multiple pressure-sealing barriers, usually located on the tubulars, to maintain well pressure and prevent unwanted fluid ingress or egress during the workover.

Process:

A hydraulic well workover is typically performed using a snubbing unit, which is a specialized piece of equipment designed to control pressure and handle the heavy tubulars involved. The process involves:

1. Installing the Snubbing Unit: The snubbing unit is rigged up at the wellhead and connected to the tubing string.
2. Establishing the Barriers: Multiple hydraulic barriers are deployed and sealed on the tubulars, creating a series of pressure-containing zones.
3. Pressure Control: The snubbing unit monitors and controls the wellbore pressure throughout the operation.
4. Workover Operation: The actual workover operation is then performed within the isolated section of the wellbore, which can include tasks like:
   • Replacing or repairing downhole equipment
   • Running or pulling tubing
   • Performing other remedial operations
5. Removal of the Barriers and Snubbing Unit: Once the workover is completed, the barriers are released, and the snubbing unit is disconnected.

Benefits of Hydraulic Well Workover:

• Reduced Time and Cost: Eliminating the need to kill the well significantly reduces the time and cost associated with workover operations.
• Minimized Risk of Formation Damage: By avoiding the introduction of large volumes of drilling fluid, formation damage is minimized, leading to improved well productivity.
• Enhanced Safety: The controlled pressure environment and elimination of high-pressure kill operations enhance safety for personnel and equipment.
• Environmental Benefits: Less fluid usage and reduced emissions contribute to a more environmentally friendly operation.

Applications:

Hydraulic well workover techniques are commonly employed for various operations, including:

• Repairs to downhole equipment
• Tubing replacement or running
• Well stimulation treatments
• Production optimization
• Retrieving lost tools

Conclusion:

Hydraulic well workover using snubbing units is a valuable technique for performing workover operations without killing the well, offering significant advantages in terms of efficiency, safety, and environmental impact. It is particularly well-suited for operations where maintaining well pressure is critical and where formation damage must be minimized. As the industry seeks to optimize well production and reduce operational costs, hydraulic well workover is likely to play an increasingly important role in future oil and gas production operations.