Prevention of Drill Stem Failures(钻杆故障的预防).pdf

Technology Transfer Package
Prevention of Drill
Stem
Failures
Schlumberger Sedco Forex SFM -PDF- 97
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Engineering Departm ent
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Introduction (1)
■ Premature and unexpected failures of drill stems cause
great losses in time and material.
■ Reducing drill stem failures will improve rig operating
performance and reduce expenses
■ The purpose of this Technology Transfer package is to
provide information to help reduce the frequency and
impact of drill stem failures.
Schlumberger Sedco Forex SFM -PDF- 97
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Engineering D epartm ent
2
Introduction (2)
■ TT PACKAGE OUTLINE
– What is a Drill Stem Failure?
– Mechanisms of Failure
– Prevention of Drill Stem Failures
– Inspection
Schlumberger Sedco Forex SFM -PDF- 97
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Engineering Departm ent
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What is a Drill Stem Failure?
■ When ponent cannot perform its function
– Complete separation (parting)
– Leak (washout)
■ Location
– Tube body, Tool Joint or Threads
– Any ponent
Schlumberger Sedco Forex SFM -PDF- 97
4
Engineering Departm ent
ΠAn event does not have to be catastrophic, such as the
parting of the drill stem, in order to be considered a failure. A
washout is as much a failure of a drill ponent as a twist
off.
• There are many definitions for the term “failure” which may
cause some confusion. In general, when a drill stem leaks or
breaks, or cannot perform in the manner for which it was
designed, the drill stem can be considered to have failed.
Ž This definition is not all inclusive. Obviously occurrences
such as wash outs, twist offs, belled or split boxes, stretched
pins, etc.. are considered failures. However, local experience
and operating conditions have to be considered when applying
the term “failure” to other less obvious occurrences such as
worn tool joints. The terms “routine” or “normal” that apply to
operating conditions in one area may be considered “unusual”
or “severe” in another area.
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What is a Drill Stem?
Compone