Page 291 - Drilling Technology in Nontechnical Language

282 Drilling Technology in Nontechnical Language Second Edition

This seals on the drillpipe while allowing rotation and movement of
the drillstring. It is necessary to do this so that the actual pressure at the

bottom of the hole (drilling fluid hydrostatic pressure + surface pressure)
can be controlled.
Horizontal oil wells are drilled in the Austin Chalk in Texas that
produce so much oil during drilling that the wells are paid for by the time

they are finished.

Certi cation of Personnel for Well Control

Most government authorities worldwide now require supervisory staff
on drilling operations to be demonstrably competent in basic well control
techniques. This requirement is most often met by taking a course and
passing a test, which incorporates both theoretical training and testing and
practical training and testing, using a simulator. The certificate is only

valid for two years, and consequently regular training and retesting has to
be completed.
Many personnel nowadays will only encounter a few kicks throughout
an entire career, unless they drill many exploration wells. As with any
skill, if it is not regularly practiced, the skills get rusty with time. While
having a current well control certificate does not guarantee an ability to

handle a well control incident calmly and properly, it should demonstrate
that the knowledge and ability exist.

Summary

This chapter described the three levels of well control (primary,
secondary, and tertiary). Well control equipment was covered in some
detail, including blowout preventers and control systems, chokes, and kick
detection equipment. Next an example was given of a kick and killing the
well, with the necessary calculations. Some special well control situations
were described in sufficient detail to give a basic understanding of the

terms used. Finally, current requirements for certification of personnel
were included.

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