LWD Standard Data Processing
ODP logging contractor: LDEO-BRG
Hole: 1167B
Leg: 188
Location: Prydz Bay (Antarctic Ocean)
Latitude: 66° 24.0' S
Longitude: 72° 17.0' E
Logging date: February 28-29, 2000
Bottom felt: 1652 mbrf
Total penetration: 260 mbsf
Logging
Runs
Logging string 1: CDR/MWD (Logging While
Drilling)
Hole 1167B was logged while drilling. The
rate of penetration averaged 21 m/hr. The CDR recorded resistivity and natural
gamma ray logs in memory; the MWD Power-Pulse tool logged drilling parameters
such as weight-on-bit and torque and transmitted the data to the ship in real
time.
Processing
Depth shift: The original logs were shifted to the sea floor
(-1652m). The sea floor depth is determined by the step in gamma ray values at
the sediment-water interface.
Gamma-ray processing: Only the total gamma ray log (GR) is available at
present. Spectral gamma ray measurements are being re-processed by Anadrill
after problems were found in the initial logs.
Quality
Control
During the processing, quality control of the
data is mainly performed by cross-correlation of all logging data. Comparison
to the wireline logs over the equivalent depth interval in Hole 1167A show that
whereas the wireline measurements are affected by hole wash-out in places, the
LWD measurements are not. Where the wireline hole is good, the LWD logs compare
favorably to the wireline logs.
Additional information about the logs can be
found in the "Explanatory Notes" and Site Chapter, ODP IR Volume 188.
For further questions about the logs, please contact:
Cristina Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia