Wireline Standard Data Processing
ODP logging
contractor: LDEO-BRG
Well name: 661A
Leg: 108
Location: Sierra Leone Rise (tropical NE Atlantic)
Latitude: 9° 26.81' N
Longitude: 19° 23.166' W
Logging date: March, 1986
Bottom felt: 4023.2 mbrf (used for depth shift to sea floor)
Total penetration: 296.1 mbsf
Total core recovered: 235.1 m (79.3 %)
Logging
Runs
Logging string 1: DIT/LSS/GR
An attempt to run the LDT/CNTG/NGT logging string failed.
No information available about use of wireline heave compensator 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 and drill string and/or wireline stretch.
DIT/LSS/GR: Bottom-hole assembly at ~70 mbsf.
Processing
Depth shift: Original logs have been depth shifted to the sea floor (- 4023.2 m).
Acoustic data processing: The long spacing sonic data were of good quality and did not need further processing.
Quality
Control
During the processing, quality control of the data is mainly performed by cross-correlation of all logging data. Log data at hole 661A are of good quality.
Data recorded through bottom-hole assembly should be used qualitatively only because of the attenuation on the incoming signal.
Hole diameter was recorded by the 3-arm mechanical caliper device (MCD).
Additional information about the logs can be found in the "Explanatory Notes" and Site Chapter, ODP IR volume 108. For further questions about the logs, please contact:
Cristina
Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia