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Ensuring Success When Setting Off-Bottom Cement Plugs

When it comes to setting off-bottom cement plugs, your success rate matters. Explore how you can achieve 100% success.

The key challenge

Establish a reliable support on your first attempt

4 closest

A potential solution

To insert a mechanical base for the cement: The Cement Support Tool (CST)

Learn about the technology

Browse the different CST Models

4 700+ Number of CSTs delivered world wide
45+ Number of countries delivered to
97.2% Current success rate for the Cement Support Tool

The Cement Support Tool (CST)

Designed to be pumped through long work strings, the CST effectively exits and fills the open or cased hole, ensuring robust support for the off-bottom cement plug. This design simplifies the cementing process, making it more efficient and reliable.

The CST is available in five standard sizes, with an additional customized version specifically for coiled tubing. This variety ensures that you can select the perfect size for your specific cementing needs, maximizing the effectiveness and reliability of your operations.

Choosing the right CST size is straightforward and depends on two key factors:

  • The inner diameter of your work string

  • The inner diameter of the open or cased hole where the cement plug will be set


Cement Support Tool


Work String Range 2 - 4½" ID
Hole / Casing Size 6 –  16" ID


Cement Support Tool


Work String Range 2 - 5” ID
Hole / Casing Size 7 - 16” ID

2 ½"

Cement Support Tool


Work String Range 2 ½ - 5.16" ID
Hole / Casing Range 7 ½" – 20" ID

2 ½"

Cement Support Tool


Work String Range 2 ½"-6"
Hole / Casing Range 7 ½" – 20" ID


Cement Support Tool


Work String Range 4" - 6.5" ID
Hole / Casing Range 8" - 42" ID

2 ⅜"

Cement Support Tool


Coil Tubing CST 2 ⅜"
Hole / Casing Range 4" - 16" ID

Explore how CST can enhance your drilling efficiency and stability, and discover tailored solutions for your specific needs.

In the complex and challenging world of well drilling, ensuring operational efficiency and minimizing costly errors is crucial.

Kick-Off  Above A "Fish"

When a drill string gets stuck, the bottom hole assembly (BHA) may be left in the hole, needing a sidetrack. A cement plug is placed to ensure success, but fluid properties can cause issues. Using the Cement Support Tool (CST) provides a stable base, ensuring nearly 100% success.

Kick-Off Above a Pilot hole

Without precise reservoir data, errors can be costly. A pilot hole is drilled to confirm Oil Water Contact (OWC) and Oil Gas Contact (OGC) depths, and must be plugged before drilling the production wellbore. Using the CST ensures nearly 100% success by providing a stable base for the cement plug.

Secure Rat Hole Below Casing

When casing is set shallow above a long rat hole, a CST can be placed 10-15 meters below the planned casing shoe depth to keep the cement slurry in place. This ensures minimal cement below the CST and increases success to nearly 100%.

P&A Exploration Wells

After drilling an exploration well, it must be plugged and abandoned, often requiring multiple cement plugs. An operator in the North Sea set four successful cement plugs using CST, saving time and costs. The process involves setting a CST below each plug and weight testing each plug for success, ensuring nearly 100% success.

P&A Production Wells

When a production well or field has ended its lifetime, it is time to Plug & Abandon (P&A) the well. Most wells will have a production tubing from the surface down to a production packer and a lower completion.

Replace Bridge Plug

Using a Bridge Plug is time-consuming since it requires multiple steps. Replacing it with a CST allows setting the CST and the P&A cement plug in a single run, saving significant rig time and cost.

Cure Downhole Losses

Downhole losses are common when drilling into weak formations. While shallow losses are easy to manage, deeper losses pose challenges. Setting a CST below the loss zone prevents mixing of well fluid and cement, ensuring a successful cement squeeze. This method has proven highly effective for many clients.

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