Page 382 - Geology and Geochemistry of Oil and Gas

GLOSSARY 343
Wireline A rope made from steel wire.
Wireline formation tester A formation fluid sampling device, actually run on
conductor line rather than wireline, that also logs flow
and shut-in pressure in formation near the wellbore.
Workover Remedial work on a well, i.e., cleaning, repairing,
servicing, stimulating, etc., after commencement of
production.
Y
Yield point The resistance to initial flow, or the stress required to
start fluid movement. The values of the yield point
and thixotropy are the measurements of the same
fluid properties under dynamic and static conditions,
respectively. Syn: Yield value.
Z
Zone of lost circulation Openings in the formation (fractures, etc.) into which
the drilling mud is lost without returning to the
surface during the drilling operations.