Page 314 - Practical Well Planning and Drilling Manual

Section 2 revised 11/00/bc 1/17/01 12:04 PM Page 290

[ ] Well Programming
2.8.3

able for all formations except extremely hard abrasive, in vertical to
high-angle wells.
To use the pressure coring system a pressure coring service unit is
positioned on the rig, which provides all required operations for the
coring run and recovery. The unit is built into a 40 ft ocean-going con-
tainer and is self-contained.
Oriented coring is available. A knife in the barrel makes a score
mark along the core at a known orientation. This allows determination
of dip and direction of formation and fracture planes. Allow time to
order the oriented coring kit.

2.8.3. Mud Logging

Mud logging involves taking measurements and samples during
drilling. This includes: taking samples of cuttings, mud, and formation
fluid shows and analyzing them; supervising, collecting and boxing
cores; logging and recording all important drilling parameters; detect-
ing and warning of the presence of problems such as kicks, H S, and
2
washouts; and producing analyses and reports. Recording quantities
and descriptions of cavings will allow close monitoring of wellbore sta-
bility and mud effectiveness as drilling progresses.
The time-based record can be invaluable when a problem occurs
and needs to be investigated later. Such problems that merit later inves-
tigation may include stuck pipe, kicks, losses, etc.
The usefulness of the service is strongly related to the quality of the
personnel. They should help the drilling supervisor to make better
decisions during drilling and will record information to improve plan-
ning for subsequent wells.
When selecting a mud logging service company, do not choose
simply on the basis of cost. First examine equipment availability, safe-
ty records, equipment reliability records, and personnel qualifications
and experience. Vendors who would be unable to provide a proper ser-
vice should be eliminated, regardless of how cheap they may be.
Mud logging unit services specification example. The following
example shows some of the services that might be specified for
mud loggers.

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