Wireline Standard Data Processing
ODP logging
contractor: LDEO-BRG
Hole: 848B
Leg: 138
Location: East Pacific Rise (tropical NE Pacific)
Latitude: 2° 59.634' N
Longitude: 110° 28.791' W
Logging date: June, 1991
Bottom felt: 3867.3 mbrf
Total penetration: 93.8 mbsf
Total core recovered: 97.8 m (104.2 %)
Logging
Runs
Logging string 1: ACT/GST/NGT
Wireline heave compensator was not used to counter ship heave.
Bottom-hole
Assembly
The following bottom-hole assembly depths are as they appear on the logs after differential depth shift (see "Depth shift" section) and depth shift to the sea floor. As such, there might be a discrepancy with the original depths given by the drillers onboard. Possible reasons for depth discrepancies are ship heave, use of wireline heave compensator, and drill string and/or wireline stretch.
ACT/GST/NGT: Bottom-hole assembly at ~86 mbsf.
Processing
Depth shift: No differential depth shift was necessary as only one logging pass was recorded. Original logs have been interactively depth shifted to the sea floor (- 3867.2 m).
Gamma-ray processing: NGT data have been processed to correct for borehole size and type of drilling fluid.
Quality
Control
null value=-999.25. This value generally appears in discrete core measurement files and also it may replace recorded log values or results which are considered invalid.
Data recorded through bottom-hole assembly should be used qualitatively only because of the attenuation on the incoming signal.
Additional information about the logs can be found in the "Explanatory Notes" and Site Chapter, ODP IR volume 138. For further questions about the logs, please contact:
Cristina Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia