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List of available measurement methods

Logging techniqueAbbreviationMeasurement parameterUnitApplication rangeBoundary conditions/influencing parameters
Gamma-ray logGRCount rate of natural γ radiationGR-APId ≥ 20 mm Caliper, probe position, drilling fluid (mud), casing and backfilling materials
Segmented gamma-ray logSGLCount rate of natural γ radiationGR-API50 ≤ d ≤ 800 mm
Gamma-Gamma logGGRelative densitycpsd ≥ 20 mmCaliper, drilling fluid (fluid), casing and backfilling materials
Gamma-gamma density logGG.Ddensityg/cm3

30 ≤ d ≤ 600 mm

(800 mm with limited informative value)

Rotating gamma-gamma density logRGG.Ddensityg/cm3100 ≤ d ≤ 125 mm
Segmented gamma-gamma density logSGG.Ddensityg/cm3150 ≤ d ≤ 800 mm
Neutron-neutron logNN

Neutron porosity%; WE

30 ≤ d ≤ 600 mm

(800 mm with limited informative value)

Caliper, drilling fluid (fluid), casing and backfilling materials
Spontaneous potential logSPPotential differencemV50 ≤ d ≤ 800 mm
below water table
Difference between drilling fluid/formation water mineralisation
Electrical laterologsELSpecific electrical resistivityΩm50 ≤ d ≤ 800 mm
below water table
Caliper, drilling fluid infiltration, water table, formation water mineralisation, drilling fluid resistance and temperature, metal pieces in borehole
Focused electrical laterologsFELSpecific electrical resistivityΩm50 ≤ d ≤ 800 mm
below water table.
Induction logILElectrical conductivitymS/cm50 ≤ d ≤ 500 mm
Magnetic susceptibility logMALMagnetic susceptibilitySI-unit20 ≤ d ≤ 800 mmCaliper, metal parts in borehole
Electro-magnetic defectoscopeEMDSWall thicknessmm50 ≤ d ≤ 500 mm            Metal casing
except stainless steel
Metal grade of casing, casing diameter
Acoustic borehole imagerABI Amplitude,
travel time
mV and µs80 ≤ d ≤ 300 mm
below water table
Caliper, probe position, drilling fluid, pipe deposits
TV probesTVOptical image of the borehole wall/casingd ≥ 20 mmOptical transparency
Optical borehole imagerOBIBorehole wall in real colours80 ≤ d ≤ 400 mm          
Spectral adsorption coefficientSACOptical absorption over specific wavelength ranges1/m80 mm < d
below water table
Impeller flowmeter logFLOWRelative flow velocitycps

d ≥ 50 mm
below water table
Caliper, drilling fluid, drilling speed, pump position
Milieu logMIL

pH value,

redox potential,

O2 content,

electrical conductivity,

temperature
-
mV
mg/l
mS/cm
°C
50 ≤ d ≤ 1000 mm
below water table
Temperature logTEMPTemperature°Cd ≥ 20 mmTemperature equalisation
Electrical conductivity /salinity logSALElectrical conductivitymS/cm50 mm ≤ d
below water table
Temperature
Tracer-fluid loggingTFLTracer-dependent measurement parameters50 ≤ d ≤ 1000 mm
below water table
Caliper, mineralisation, transparency, tracer density
Photometric turbidity measurementPTMTurbidityFAUd ≥ 60 mm
below water table
Transparency
Caliper logCALDiametermm50 ≤ d ≤ 1500 mm

Inclination, probe position

Borehole deviation logBDL

Inclination,

direction of inclination
Grad
Grad
d ≥ 20 mmCasings (steel)
Packer flowmeter logPFLOWRelative permeabilitycps80 ≤ d ≤ 400 mm
below water table
Drilling speed, caliper, pipe deposits, well screen, filter gravel
Gas-dynamic testGDTRelative gas saturation%40 ≤ d ≤ 800 mm
below water table

Type of casing

GDT not possible with surface casing seal
Temperature monitoringTEMP.MONTemperature°Cd ≥ 20 mmTemperature equalisation
Depth-oriented samplingSAMPd ≥ 60 mm

Source: DVGW-Arbeitsblatt W 110