Page 497 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:30 PM Page 473

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Glossary

thread lubricant containing not less than 40-60% by weight of finely
powdered zinc or not less than 60% of finely powdered lead and with
a coefficient of friction not less than 0.08. For drill collars greater
than 7 inches OD, a thread lubricant with a lower coefficient of fric-
tion should be used (a “slicker” grease) due to the higher make-up
torques required by the larger shouldered connections.

Drawworks. The hoist used to control movement of the travelling
block by winding in or out the blockline on a drum. Releasing move-
ment usually controlled by a band or disk brake, sometimes assisted
by a movement brake (eddy current or hydromatic).

Drill Stem Test (DST). A test run with the drill string to determine
whether oil and/or gas in commercial quantities has been encoun-
tered in the well bore.

Drill Stem. The entire drilling assembly from the swivel to the bit;
composed of the kelly, drill pipe with tool joints, subs, drill collars,
stabilizers, shock absorbers, and reamers. Used to rotate the bit and
to carry the mud or circulating fluid to the bit.

Drilling Mud or Drilling Fluid. A circulating fluid used in rotary
drilling to perform any or all of various functions required in the
drilling operation.

Drilling Out. The operation during the drilling procedure when the
cement is drilled out of the casing before further hole is made or
completion attempted.

Drilling Under Pressure. Carrying on drilling operations while main-
taining a seal at the top of the well bore to prevent the well fluids
from blowing out.

Dual Induction Resistivity Log. Schlumberger wireline tool that
records a Spontaneous Potential log and three resistivity curves at dif-
ferent depths. Used to deduce true formation resistivity Rt, invasion
profiles, and quicklook Hydrocarbon detection.

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