Geophysical Logs in the PDMS are logs that portray rock properties measured with wireline logging tools.
In the PDMS, Geophysical Logs are divided into groups of similar Log Types as shown in the table below. The Log Code is used internally by the IGS to organize digital log files and is not an individual data field in the Log Info Subtable.
A Log Code is assigned to most Geophysical Log Types for convenience in organizing and retrieving digital log files in the PDMS. The Log Code forms part of the file name assigned to the digital (scanned) logs; see Naming Scanned Documents in the PDMS for a more detailed explanation.
The General Name for Log Orders column is merely provided for convenience and improved communication when ordering logs from the Indiana Geological Survey.
Log Type |
Log Code |
General Name for Log Orders |
Explanation |
|
|
|
|
Borehole Imaging Log |
BIL |
high-resolution imaging of borehole circumference using closely spaced log measurements, typically of micro resistivity or sonic transit time |
|
Caliper Log |
CAL |
measures width of the borehole |
|
Composite Log |
COP |
log combines curves and data from several other log type. |
|
Computed Log |
CUL |
any log that attempts to characterize the formation by computer analyses of multiple other logs that have been run in the well |
|
Density Log |
DL |
Density Porosity Log |
records electron density in the formation; usually has a gamma ray curve; does not include density-neutron logs |
Density-Neutron Log |
DNL |
Density Porosity Log |
porosity log with at least one density curve and at least one neutron curve |
Dipmeter Log |
DIP |
Dipmeter Log |
records the attitude (dip angle and dip direction) of rock layers in the borehole |
Electric Log |
EL |
Electric Log |
open hole log with an SP curve and typically a non-induced resistivity curve |
EPT Log |
EPT |
measures propagation and attenuation of electromagnetic waves through a formation |
|
Fracture ID Log |
FID |
a special presentation of dipmeter micro resistivity measurements that identifies fractures |
|
Gamma Ray Log |
GR |
Gamma-Ray Log |
log which only records natural radioactivity (logs with other curves are a different Log Type) |
Gamma Ray Spectral Log |
SPC |
uses gamma ray energy spectrum to record potassium, uranium, and thorium in the formation |
|
Induction Log |
IL |
Electric Log |
SP log with one or more induced resistivity curves (including focused and laterologs) |
Magnetic Resonance Log |
MRL |
Magnetic Resonance Porosity Log |
porosity log based on measuring the signal generated by polarized hydrogen protons. |
Micro Log |
ML |
Micro Log |
micro-resistivity log |
Neutron Log |
NTR |
Neutron Porosity Log |
records hydrogen concentration in the formation; usually has a gamma ray curve; does not include density-neutron logs |
Production Log |
PRL |
Production Log |
any of various logs used in completing a well for production |
RFT (Repeat Formation Test) Log |
RFT |
records formation pressure data (and obtains a small rock sample) of the formation |
|
Sonic Log |
SL |
Sonic Porosity Log |
porosity log based on transit time of sound waves through the formation |
Temperature Log |
TMP |
records temperature of drilling mud in the borehole |
|
TVD Log |
TVD |
TVD Log |
No longer used in Geophysical Log Types Subtable!
A TVD Log, TVD Report, or Directional Survey records the position and attitude of a borehole path in a deviated well. In earlier versions of the PDMS, the term "TVD Log" in the LogInfo Subtable and "TVD Report" in the Reports Subtable coexisted as mutually exclusive options for recording a Directional Survey in the PDMS. This duality caused difficulties when these records were used in PDMS queries and calculations. To address this situation, "TVD Log" was eliminated as a data field in the Geophysical Logs Subtable; and:
all Directional Surveys, TVD Logs, TVD Reports are now entered as TVD Reports in the Reports Subtable. |
Indiana Geological Survey, PDMS Help Topic, Updated April 1, 2011