| Logging technique | Abbreviation | Measurement parameter | Unit | Application range | Boundary conditions/influencing parameters |
|---|---|---|---|---|---|
| Gamma-ray log | GR | Count rate of natural γ radiation | GR-API | d ≥ 20 mm | Caliper, probe position, drilling fluid (mud), casing and backfilling materials |
| Segmented gamma-ray log | SGL | Count rate of natural γ radiation | GR-API | 50 ≤ d ≤ 800 mm | |
| Spectral gammaray log | SGR | U & Th content; K content | ppm; % | 80 ≤ d ≤ 500mm | |
| Gamma-Gamma log | GG | Relative density | cps | d ≥ 20 mm | Caliper, drilling fluid (fluid), casing and backfilling materials |
| Gamma-gamma density log | GG.D | density | g/cm3 | 30 ≤ d ≤ 600 mm (800 mm with limited informative value) | |
| Rotating gamma-gamma density log | RGG.D | density | g/cm3 | 100 ≤ d ≤ 125 mm | |
| Segmented gamma-gamma density log | SGG.D | density | g/cm3 | 150 ≤ d ≤ 800 mm | |
| Neutron-neutron log | NN | Neutron porosity | %; WE | 30 ≤ d ≤ 600 mm (800 mm with limited informative value) | Caliper, drilling fluid (fluid), casing and backfilling materials |
| Spontaneous potential log | SP | Potential difference | mV | 50 ≤ d ≤ 800 mm below water table | Difference between drilling fluid/formation water mineralisation |
| Electrical laterologs | EL | Specific electrical resistivity | Ωm | 50 ≤ 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 laterologs | FEL | Specific electrical resistivity | Ωm | 50 ≤ d ≤ 800 mm below water table. | |
| Induction log | IL | Electrical conductivity | mS/cm | 50 ≤ d ≤ 500 mm | |
| Magnetic susceptibility log | MAL | Magnetic susceptibility | SI-unit | 20 ≤ d ≤ 800 mm | Caliper, metal parts in borehole |
| Electro-magnetic defectoscope | EMDS | Wall thickness | mm | 50 ≤ d ≤ 500 mm Metal casing except stainless steel | Metal grade of casing, casing diameter |
| Acoustic borehole imager | ABI | Amplitude, travel time | mV and µs | 80 ≤ d ≤ 300 mm below water table | Caliper, probe position, drilling fluid, pipe deposits |
| TV probes | TV | Optical image of the borehole wall/casing | d ≥ 20 mm | Optical transparency | |
| Optical borehole imager | OBI | Borehole wall in real colours | 80 ≤ d ≤ 400 mm | ||
| Spectral adsorption coefficient | SAC | Optical absorption over specific wavelength ranges | 1/m | 80 mm < d below water table | |
| Impeller flowmeter log | FLOW | Relative flow velocity | cps | d ≥ 50 mm below water table | Caliper, drilling fluid, drilling speed, pump position |
| Milieu log | MIL | pH value, redox potential, O2 content, electrical conductivity, temperature | - mV mg/l mS/cm °C | 50 ≤ d ≤ 1000 mm below water table | |
| Temperature log | TEMP | Temperature | °C | d ≥ 20 mm | Temperature equalisation |
| Electrical conductivity /salinity log | SAL | Electrical conductivity | mS/cm | 50 mm ≤ d below water table | Temperature |
| Tracer-fluid logging | TFL | Tracer-dependent measurement parameters | 50 ≤ d ≤ 1000 mm below water table | Caliper, mineralisation, transparency, tracer density | |
| Photometric turbidity measurement | PTM | Turbidity | FAU | d ≥ 60 mm below water table | Transparency |
| Caliper log | CAL | Diameter | mm | 50 ≤ d ≤ 1500 mm | Inclination, probe position |
| Borehole deviation log | BDL | Inclination, direction of inclination | Grad Grad | d ≥ 20 mm | Casings (steel) |
| Packer flowmeter log | PFLOW | Relative permeability | cps | 80 ≤ d ≤ 400 mm below water table | Drilling speed, caliper, pipe deposits, well screen, filter gravel |
| Gas-dynamic test | GDT | Relative gas saturation | % | 40 ≤ d ≤ 800 mm below water table | Type of casing GDT not possible with surface casing seal |
| Temperature monitoring | TEMP.MON | Temperature | °C | d ≥ 20 mm | Temperature equalisation |
| Depth-oriented sampling | SAMP | d ≥ 60 mm |
Source: DVGW-Arbeitsblatt W 110