Page 107 - Drilling Technology in Nontechnical Language

98 Drilling Technology in Nontechnical Language Second Edition

Fig. 4–12. Heave compensator—principal of operation

Kicking off the well

When drilling a directional well, the kickoff point has to be carefully
chosen. For the kickoff to be controllable, the hole has to be stable (stays

equal to the drillbit diameter) over the buildup interval. A significantly
enlarged hole makes accurate directional control impossible.
The kickoff should be started and finished in one hole section. It is

better not to run casing halfway through the kickoff, because if the casing
is drilled out and a curved wellbore continued, the drillpipe can wear a
groove in the casing shoe on the inside of the bend.
Apart from the damage to the casing, the drillpipe can get stuck in this

groove when pulling out of the hole. It is better to finish the kickoff and
protect it by running casing reasonably quickly afterwards.

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