Page 216 - Drilling Technology in Nontechnical Language

Chapter 9 – CASING AND CEMENTING 207

Fig. 9–5. Cement ow around uncentralized casing

It is important that the casing is well centralized, and to ensure this, a
tool is fastened to the outside of the casing that pushes the casing off the
wall. These tools are called centralizers. A centralizer is made of strips
of spring steel, held together at the top and bottom with a steel ring that

hinges open so that it can be placed on the pipe (fig. 9–6).

Fig. 9–6. A spring centralizer on casing

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