Introducing The Guardian™

Blowouts, pressure level issues, equipment damage – all common problems during drilling, production and completion. To protect the wellbore, you’ve used downhole well control devices, but have they done the job effectively?

What Is A Downhole Well Control Device

Specialized tools and systems located inside the tubing or casing in an oil or gas well to prevent and manage the uncontrolled flow of formation fluids into the wellbore. These are vital components to ensuring the safety of your workers and the environment.

From Blowout Preventers (BOPs) to tubing plugs and profiles these tools seal and control, from potential unplanned releases of hydrocarbons. When these downhole and surface devices fail this becomes one of the most dangerous and technically complex situations in the oilfield. Controlling a wild well presents a unique set of extreme challenges that demand technical precision, coordination, and caution. High wellbore pressures and uncontrolled flow rates can exceed the limits of surface equipment, while the potential for fire or explosion makes approaching the site extremely hazardous. In many cases, the blowout damages the wellhead or blowout preventer, leaving crews with limited mechanical options to regain control. Unknown downhole conditions and changing pressures add further uncertainty, making every move critical. Environmental factors—such as weather, terrain, or offshore conditions—can slow response efforts, while drilling a relief well to kill the blowout is a complex and time-consuming process that requires accuracy and stability under pressure. Beyond the technical obstacles, the safety of personnel and environmental protection remain the top priorities, requiring coordinated efforts between operators, regulators, and emergency response teams to contain the situation and restore well control safely.

While fishing operations are common, they are extremely time-consuming, expensive and they put your operator at risk as they work in dangerous conditions and face uncertain challenges.

Workover Solutions (WOS) developed the Guardian™ system, a contingency, on-demand dual flapper check valve assembly, designed as a backup well control device to eliminate downhole flow control failures. This uses the same dependable design principles and materials utilized in the WOS dual and quad flapper assemblies.

In a recent thru-tubing operation with cleanouts and fishing jobs in the Vaca Muerta Shale zone, Northern Patagonia, Argentina the operator experienced safety check valve washouts and improperly machined nipple profiles, creating well control issues and resulting in two lost work strings that required fishing operations.

The Guardian™ was called in to use as a backup downhole well control device to eliminate these fishing operations. The tool is run in the passive mode and remains as such until activated by dropping a 1” ball, which is then captured within the tool to not interfere with ball drop activated tools run beneath. The tool also allows for the passing of up to a ¾” ball through the assembly for activation of tools below without adverse effect. The ball drop design reduces time to activate check valves and continue drilling. This design also allows the operator to continue drilling and get to TD eliminating a trip and completing the well on time.


After WOS delivered the initial 2.88” sized tool, it was quickly scaled to 3.13” to meet the customer’s needs. This compact design tool, 26.04” in overall length, offers a low-cost value to limit the high-cost risk of well control issues. Made in the USA, the tool is rebuilt, pressure-tested and inspected by trained WOS personnel in Argentina.

Ten additional units are in manufacturing to expand the fleet and the Guardian™ is now mandatory for all snubbing unit operations for the operator.

If you want more information on the Guardian™ or have any questions, reach out to your WOS representative, give us a call on our main line at 346-774-4433, or email us at sales@wos.com.

Benefits

  • Large diameter bore preventing pressure increase
  • Viton seals and o-rings for compatibility with harsh fluid
  • Allows for continued drilling in the case of a flapper valve washout
  • Prevents tripping pipe in the event of a washout
  • Ensures well control with a passive set of valves
  • Secondary well control device increasing safety

Accessories

  • WOS PowR Motors
  • WOS High Flow Check Valves
  • WOS AV Sub
  • WOS Flex Sub
  • WOS PulverizR Bits
  • BitSavR