Wireline Standard Data Processing

ODP logging contractor: LDEO-BRG

Hole: 934-B

Leg: 155

Location: Amazon Fan (equatorial NW Atlantic)

Latitude: 5° 29.020' N

Longitude: 47° 40.860' W

Logging date: April, 1994

Bottom felt: 3432 mbrf

Total penetration: 108.8 mbsf

Total core recovered: 106.9 m (98.3 %)

Logging Runs

Logging string 1: DIT/NGT

        

Wireline heave compensator was 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.

        

DIT/NGT: bottom hole assembly at ~ 49 mbsf.

Processing

Depth shift: No differential depth shift necessary, as only one tool string was run.

Gamma-ray processing: Data have been processed to correct for borehole size and type of drilling fluid.

Quality Control

As no caliper was recorded, no quality control is possible at this hole. A constant value of 10.25" (which should theoretically correspond to a hole drilled with a 9.875" bit size) has been used in the NGT processing. Based on experience at other holes from Leg 155, however, this value is likely to be an underestimate of the actual borehole size; this would cause the NGT correction for borehole size to be underestiomated as well.

        

Data recorded through bottom hole assembly, such as the NGT data recorded above 49 mbsf should be used qualitatively only because of the attenuation on the incoming signal.

Details of standard shore-based processing procedures are found in the "Explanatory Notes" chapter, ODP IR Volume 155.

For any question about the data or about the LogDB database, please contact LogDB support: logdb@ldeo.columbia.edu.