Page 229 - Drilling Technology in Nontechnical Language

220 Drilling Technology in Nontechnical Language Second Edition

Fig. 9–12. Plugs landed

Cementing Surface Casings

Surface casing is large diameter, so that several more strings of casing

can fit inside it and still have a big enough hole through the reservoir to

be able to log it and produce from it. Large diameter casing is difficult to
handle and to run, especially in any significant wind, unless automated

handling equipment is used on the rig. A 40 ft joint of pipe, 20" in diameter
and weighing around 4,000 lb, will be tricky enough to manipulate even
in good weather conditions. If the top of the casing is slightly off center,
the casing connection thread is likely to become cross-threaded, where
the threads on the male end (bottom of the joint of casing) do not quite

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