Well Log Mnemonics Additional reference:  http://www.posc.org/Epicentre.2_2/DataModel/LogicalDictionary/StandardValues/wltcachanges.html Functions short  Typical
Mnemonics Description ? Company Notes function Scale range Unit
2IL dual induction focused log Birdwell
ABC acoustic borehole compensated Birdwell acoustic transit time porosity
AIT Array induction tool conductivity conductivity
AO AIT log with 1 ft vertical resolution Schlumberger AIT- Array induction tool, resistivity image showing bedding, HC content, invasion features Shallow resistivity, invasion resistivity, HC saturation resistivity 0.2 2000 ohm/m
AO10 AIT log with 1 ft vertical resolution Schlumberger AIT- Array induction tool, resistivity image showing bedding, HC content, invasion features, 10 inch depth conductivity 0.2 2000 ohm/m
AO90 AIT log with 1 ft vertical resolution Schlumberger AIT- Array induction tool, resistivity image showing bedding, HC content, invasion features, 90 inch depth conductivity 0.2 2000 ohm/m
APS EPI POR LS COR accelerator porosity sonde epithermal porosity long spaced corrected Schlumberger bull density, neutron porosity, thin beds, high radioactivity density porosity 45 -15 pu
ASN AMPLIFIED SHORT NORMAL Schlumberger resistivity image
AT AIT log with 2 ft vertical resolution Schlumberger see AO 0.2 2000 ohm/m
ARI azimuthal resistivity imager Schlumberger resistivity image image
BCA borehole compensated acoustic BPB Instruments acoustic transit time transit time
BCN borehole compensated neutron log NL McCullough neutron neutron
BCS borehole compensated sonic Gearhart acoustic transit time porosity
BGT borehole geometry log Schlumberger borehole size caliper
BHC BHC acoustilog Dresser Atlas acoustic transit time porosity
BHC BHC sonic log Schlumberger acoustic transit time porosity
BHGM borehole gravity meter Edcon gravity gravity
BMIN Microresistivity permeable zone id, bed boundaries, sand count, caliper, mud thickness image 0 20 ohm/m
BMNO Microresistivity permeable zone id, bed boundaries, sand count, caliper, mud thickness image 0 20 ohm/m
BRD bed resolution density BPB Instruments density  density
BS bit size drill bit size bit size 6 16
BSAL borehole salinity ?
CA3 caliper Birdwell borehole size caliper
CA6 caliper Birdwell borehole size caliper
CAL caliper borehole diameter caliper 6 16 in
CAL caliper Birdwell borehole size caliper
CAL caliper Gearhart borehole size caliper
CALI caliper generic borehole size caliper 6 16 in
CAL caliper Welex borehole size caliper
CALS sonic caliper borehole diameter caliper 6 16 in
CAVL Compensated acoustic velocity log Welex acoustic transit time porosity
CCL casing collar locator Schlumberger production
CDL compensated density log BPB Instruments density  density
CDL compensated densilog Dresser Atlas density  density
CDL compensated density log Gearhart density  density
CDL density log compensated Welex density  density
CDN compensated density neutron tool Schlumberger neutron neutron
CDR continuous directional survey Schlumberger borehole deviation deviation
CDS continuous deviation survey BPB Instruments borehole deviation deviation
CDS continuous directional survey Gearhart borehole deviation deviation
CGR computed gamma ray Schlumberger 0 150 gapi
CGSL capture gamma spectral log Welex spectral gamma ray gamma
CHES cased hole evaluation Dresser Atlas cased hole  cased hole
CIDP phasor processed deep conductivity Schlumberger resistivity resistivity 0.2 20 ohm/m
CLASS clay analysis and shaly sand evaluation Dresser Atlas reservoir analysis reservoir
CLAYS clay analysis Dresser Atlas reservoir analysis reservoir
CLSD compensated long spacing density BPB Instruments density  density
CMR combinable magnetic resonance tool Schlumberger magnetic resonance porosity
CMS circumferential microsonic Schlumberger acoustic transit time porosity
CNL compensated neutron log Schlumberger hydrogen content neutron
CNL compensated neutron log n-t    Schlumberger neutron neutron
CNLog compensated neutron log n-t and n-e Dresser Atlas neutron neutron
CNS compensated neutron survey n-t Gearhart neutron neutron
COC spectralog carbon oxygen log Dresser Atlas spectral gamma ray gamma
CONC contact caliper log Welex nonfocused microresistivity perm indicator, microlog resistivity
COR carbon oxygen ratio Schlumberger carbon oxygen ratio C/O ratio 45 -15 pu
CMR combinable magentic resonance tool Schlumberger nuclear magnetic resonance, porosity porosity
CRA Prolog complex reservoir analysis Dresser Atlas reservoir analysis reservoir
CSF continuous spinner flowmeter Dresser Atlas production
CSNG compensated spectral natural gamma log Welex gamma, spectral gamma
CSNG compensated spectral natural gamma log Welex spectral gamma ray gamma
DBC density/borehole compensated Birdwell density  density
DCAL 1D caliper ? Schlumberger caliper caliper
DCL dielectric constant log Gearhart dielectric permittivity resistivity
DCL dielectric constant log Welex dielectric permittivity resistivity
DDFG dual dynamically focused guard log Welex focused resistivity resistivity
DEL dielectric log Dresser Atlas dielectric permittivity resistivity
DF fluid density log Birdwell fluid density production
DGFL dual guard FoRxo log Welex focused resistivity resistivity
DGL dual guard log Welex focused resistivity resistivity
DHD dual dipmeter Schlumberger dip meter dip
DHL deviated hole logging system Schlumberger borehole deviation deviation
DIFL dual induction focused log Dresser atlas induction
DIFL dual induction focused log Welex focused conductivity conductivity
DIGL dual induction guard Welex focused conductivity conductivity
DIL dual induction resistivity Schlumberger true formation resistivity, invasion profiles, correlation, quicklook HC detection, depth control induction 0.2 2000 ohm/m
DIL dual induction log Welex focused conductivity conductivity
DIP resistivity dip log Welex dip meter dip
DIRSID directional survey Dresser Atlas directional survey directional survey
DISN dual induction short normal log Welex focused conductivity conductivity
DL  density log Gearhart density  density
DLL dual laterolog Dresser Atlas focused resistivity resistivity
DLL dual laterolog Gearhart focused resistivity resistivity
DLL dual laterolog Schlumberger focused resistivity resistivity
DNL dual spaced neutron n-t BPB Instruments neutron neutron
DNLL dual detector neutron lifetime log Dresser Atlas neutron neutron
DNP dual compensated neutron n-t and n-e Schlumberger neutron neutron
DPHI density porosity ? Schlumberger density porosity density porosity
DPO LDS density porosity Schlumberger lithodensity density porosity density porosity   -0.15 v/v
DPT deep propagation log Schlumberger dielectric permittivity resistivity
DRHO delta rho Schlumberger change in density density -2500 25000 g/c3
DSI shear, compressional, and stoneley waves Schlumberger amplitude variation with AVO calibration, shear seismic correlation, wellbore stability, fracture height estimate, mobility, fracture estimation transit time
DSI dual spaced induction BPB conductivity
DSL digital sonic log Schlumberger acoustic transit time porosity
DSN dual spaced neutron log n-t Welex neutron neutron
DT delta transit time generic transit time porosity 340 40 us/f
DTCO delta transit time compressional porosity 340 40 us/f
DTL differential temperature log Gearhart temperature temperature
DTSM delta transit time shear measurement porosity 440 40 us/f
DTST delta transit time stoneley wave porosity
EL electric log dresser atlas, schlumberger, welex resistivity
ELREC electric log salt dome profile Gearhart resistivity
EMC micro contact caliper Birdwell nonfocused microresistivity perm indicator, microlog resistivity
ENP epithermal neutron log n-e BPB Instruments neutron neutron
EPT electromagnetic propagation log Schlumberger investigates flushed zone; pad; 1.1 Ghz dielectric permittivity resistivity
ES electric log Birdwell short normal, long normal, lateral and sp curves lithology
FCL FoRxo caliper log Welex focused microlaterolog resistivity
FDC formation density log compensated Schlumberger density  density
FDL formation density l Birdwell density  density
FDL fracture detection log Gearhart dip meter fractures
FE focused electric BPB Instruments focused resistivity resistivity
FED dipmeter Gearhart dip meter dip
FF fracture finder Welex acoustic amplitude, fractures amplitude
FIL Fracture identification log Schlumberger dip meter fractures
FIT formation interval tester Schlumberger formation fluid and pressure  formation
FMT formation multitester Dresser Atlas formation fluid and pressure  formation
FPL fracture profile log Welex dip meter fractures
FRAC fracture analysis Dresser Atlas fracture analysis fractures
FWAL full wave acoustic log Welex acoustic wave train porosity
GCL Continuous guidance log Schlumberger borehole deviation deviation
GDS guard log Birdwell focused resistivity resistivity
GFL Guard-FoRxo Welex focused resistivity resistivity
GL guard log Gearhart focused resistivity resistivity
GL guard log Welex focused resistivity resistivity
GR gamma ray all radioactivity gamma 0 150 API units
GRB gamma ray backup radioactivity gamma 100 200 API units
GST gamma spectrometry log Schlumberger gamma, spectral gamma 0 250 API units
GST gamma spectrometry log Schlumberger spectral gamma ray gamma 0 250 API units
HCGR hostile natural gamma ray sonde computed gamma ray Schlumberger gamma ray gamma 0 150 API units
HDT-E high resolution digital dipmeter Schlumberger dip meter dip
HLDT hostile environment lithodensity tool Schlumberger density, lithology, porosity, caliper density porosity
HRC hard rock coring tool Gearhart sidewall cores cores
HRD high resolution density BPB Instruments density  density
HRDIP Hi Resolution 4 arm diplog Dresser Atlas dip meter dip
HRT high resolution thermometer Schlumberger temperature temperature
HSGR hostile natural gamma ray sonde standard gamma ray gamma ray gamma 0 150 API units
IDER enhanced phasor processed deep resistivity Schlumberger resistivity resistivity 0.2 20 ohm/m
IEL induction electric Gearhart focused conductivity conductivity
IEL induction electric log Welex focused conductivity conductivity
IES induction electric Birdwell conductivity
IL induction log Gearhart, Schlumberger conductivity
ILD deep induction standard processed resistivity Schlumberger conductivity conductivity 0.2 2000 ohm/m
ILM medim induction standard processed resistivity Schlumberger conductivity conductivity 0.2 2000 ohm/m
IMER Enhanced phasor processed medium resistivity Schlumberger conductivity conductivity 0.2 20 ohm/m
IS induction Birdwell
ISF ISF induction log Schlumberger focused conductivity conductivity
L laterolog Schlumberger focused resistivity resistivity
LCRA lithology complex reservoir analysis Dresser Atlas reservoir analysis reservoir
LDS lithodensity Schlumberger density density
LDT  litho density compensated Schlumberger density  density
LDT-CNL lithodensity/compensated neutron log
LL laterolog Dresser Atlas linear scale focused resistivity resistivity linear linear
LLD laterolog deep log scale / part of dual laterolog resistivity resistivity 0.2 2000 ohm/m
LLS laterolog shallow log scale / part of dual laterolog resistivity resistivity 0.2 2000 ohm/m
LN LONG NORMAL 64" Schlumberger ELEC RESISTIVITY resistivity
LSAL long spaced acoustic velocity log Welex acoustic transit time porosity
LSBHC long spaced BHC acoutilog Dresser Atlas acoustic transit time transit time
LSD long spacing density BPB Instruments density  density
LSS long spaced sonic Gearhart acoustic transit time porosity
LSS long spaced sonic Schlumberger acoustic transit time porosity
MCS multichannel sonic BPB Instruments acoustic transit time porosity
MEL micro electric log Gearhart nonfocused microresistivity perm indicator, microlog resistivity
MIS magnetic inclinometer survey Birdwell borehole deviation deviation
ML minilog Dresser Atlas nonfocused microresistivity perm indicator, microlog resistivity
ML microlog Schlumberger nonfocused microresistivity perm indicator, microlog resistivity
MLL micro resistivity BPB Instruments focused microlaterolog resistivity
MLL micro laterolog Gearhart focused microlaterolog resistivity
MLL microlaterolog Schlumberger focused microlaterolog resistivity
MRIL magnetic resonance imaging log NUMAR nuclear magnetic resonance, porosity porosity
MSF  microspherically focused log Gearhart focused microlaterolog resistivity
MSFL MicroSFL resistivity Schlumberger see AO / often part of dual laterlog combination/ log scale resistivity
MSFL Microresistivity   resistivity of flushed zone, porous & permeable zones, movable HC, caliper resistivity 0.2 2000 ohm/m
MSFL micro sfl Schlumberger focused microlaterolog resistivity ohm/m
MSG microseismogram Welex acoustic wave train seismic
MST multiset tester Welex formation fluid and pressure  formation
NBC neutron borehole compensated n-t Birdwell neutron neutron
NGS natural gamma ray spectrometry log Schlumberger thorium, potassium, uranium curves gamma 0 250 API units
NGS natural gamma ray spectrometry log Schlumberger gamma, spectral gamma 0 250 API units
NGS natural gamma ray spectrometry log Schlumberger spectral gamma ray gamma 0 250 API units
NL neutron log n-gamma and n-e, n-t Birdwell neutron neutron
NL neutron log n-gamma    Schlumberger neutron neutron
NL neutron log n-gamma and n-t Welex neutron neutron
NLL neutron lifetime log Dresser Atlas neutron neutron
NML nuclear magnetism log Dresser Atlas free fluid fluid
NML nuclear magnetism log Schlumberger free fluid fluid
NMR nuclear magnetic resonance Schlumberger nuclear magnetic resonance, porosity porosity
NN neutron n-t BPB Instruments neutron neutron
NPHI neutron porosity hydrogen content, gas detection, lithology did, clay analysis, porosity analysis neutron 0.6 0 v/v
NPOR neuton porosity ? neutron neutron
NPLT nuclear porosity lithology tool Schlumberger combined gamma density, neutron porosity, and gr spectrometry gamma
PCD powered caliper device Schlumberger borehole size caliper
PE photoelectric generic photoelectric lithology
PEF photoelectric effect Schlumberger photoelectric lithology 0 10
PEFL photoelectric effect long Schlumberger photoelectric lithology 0 10
PEFS photoelectric effect short Schlumberger photoelectric lithology 0 10
PHIE Porosity Schlumberger see AO Porosity porosity 0.02 200 ohm/m
PHILC accelerator porosity sonde epithermal porosity long spaced corrected Schlumberger same as APS EPI… porosity 45 -15 pu
PHIN neutron porosity generic neutron porosity 45 -15 pu
PL pressure log Birdwell pressure pressure
PL proximity log generic resistivity resistivity
PML proximity minilog Dresser Atlas focused microlaterolog resistivity
PNL pulse neutron log generic used in cased hole indirect chlorine concentration hydrocarbon detection
POTA potassium curve Schlumberger potassium curve gamma 0 0.1
PTL precision temperature log Welex temperature temperature
RFT repeat formation tester Schlumberger formation fluid and pressure  formation
RHOB     bulk density Schlumberger bulk density density 2 3 g/c3
RMA radioactive mineral analysis Dresser Atlas reservoir analysis reservoir
RX0 Microresistivity generic resistivity of flushed zone  resistivity 0.2 2000 ohm/m
SAND Prolog Sandstone Analysis Dresser Atlas sandstone analysis sandstone
SCCL shale compensated chlorine log NL McCullough spectral gamma ray gamma 0 250 API units
SDA stratadip analysis Dresser Atlas dip meter dip
SDL spectral density log density  density
SDS slimline dipmeter survey BPB Instruments dip meter dip
SF spherically focused log Gearhart focused resistivity resistivity
SFAL sonic formation amplitude log Gearhart acoustic amplitude fractures amplitude
SFL Spherically focused log Schlumberger dual induction SFL array resistivity at 3 depths resistivity resistivity 0.2 20 ohm/m
SFL spherically focused log Schlumberger focused resistivity resistivity
SFLU spherically focused log, unaveraged Schlumberger resistivity resistivity 0.2 20 ohm/m
SFT select formation tester Gearhart formation fluid and pressure  formation
SFT sequential formation tester Welex formation fluid and pressure  formation
SGR spectroscopy gamma ray Schlumberger gamma 0 250 API units
SGR spectral gamma ray Gearhart gamma, spectral gamma 0 250 API units
SGR spectral gamma ray Gearhart spectral gamma ray gamma 0 250 API units
SL-A amplitude log Schlumberger acoustic amplitude amplitude
SL-WFP wave train display Schlumberger acoustic wave train seismic
SN short normal resistivity generic shallow formation resistivity resistivity 0 50 ohm/m
SNL sidewall neutron log n-e Gearhart neutron neutron
SNP sidewall neutron log n-e Schlumberger neutron neutron
SP Spontaneous potential Schlumberger detect permeable beds, bedding boundaries, formation water resistivity, and volume of shale in permeable beds reservoir rock identification, formation water resistivity lithology -160 40 mV
SPHI sonic derived porosity curve generic Porosity porosity 0.4 0 v/v
SPL spectral gamma ray Spectralog gamma, spectral gamma 0 250 API units
SS seismic spectrum Gearhart acoustic wave train seismic
SS synthetic seismogram Dresser Atlas seismic velocity seismic
SWA sidewall acoustic log Dresser Atlas acoustic transit time transit time
SWC sidewall coring Welex sidewall cores cores
SWD core gun Birdwell sidewall cores cores
SWN sidewall epithermal neutron n-e Dresser Atlas neutron neutron
SWN sidewall neutron log n-e Welex neutron neutron
TCR quantitative tracer survey CRC Wireline production
TDT thermal decay time log Schlumberger cased hole log detects HC buildups behind pipe neutron neutron
TENS tension Schlumberger drill string tension tension 12000 2000 lbf
THOR thorium curve Schlumberger thorium curve gamma 0 40 ppm
TL temperature log Birdwell temperature temperature
TL temperature log Gearhart temperature temperature
TLD differential temperature log Birdwell temperature temperature
TMD thermal multigate decay log Welex neutron neutron
TRF well treatment profile Birdwell production
TRP radioactive tracer log Birdwell production
TS temperature/differential temperature BPB Instruments temperature temperature
TVD true vertical depth Dresser Atlas True vertical depth depth
ULSEL electric log salt dome profile resistivity
URAN uranium curve Schlumberger uranium curve gamma -10 30 ppm
V3D 3-D velocity log Birdwell acoustic wave train seismic
VDL variable density log Dresser Atlas acoustic wave train seismic
VDL variable density log Schlumberger acoustic wave train seismic
VSP vertical seismic profile Dresser Atlas seismic velocity seismic
WSR well seismic record Schlumberger acoustics seismic seismic
WSS wellbore sibilation survey Birdwell noise log production
XYC x-y caliper Gearhart borehole size caliper