Page 208 - Drilling Technology in Nontechnical Language

Chapter 9 – CASING AND CEMENTING 199

▪ Protect unconsolidated surface formations from being eroded
away by the drilling fluid.

▪ Sometimes to support the weight of the wellhead and BOPs.
Figure 9–2 shows a bottom joint of 30" OD conductor pipe with a drive
shoe on the bottom. This shoe has teeth to help to break up the rock as the
conductor is hammered into the ground or seabed.

Fig. 9–2. Bottom joint of 30" diameter casing with the pile drive shoe

Surface casing

The surface casing is the first casing that is set deep enough for the
formations at the shoe to withstand pressure from a kicking formation
lower down. The purposes of the surface casing are to accomplish the
following:
▪ Allow a BOP to be connected so that the well can be
drilled deeper

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