Density Tools

A660 - MICRO DENSITY/ CALIPER
A606 - MICRO DENSITY/ CALIPER/ GAMMA
A619 - MICRO DENSITY/ PR / CALIPER / GAMMA
A656 - SLIM DENSITY
A659 - DENSITY/ CALIPER
A605 - DUAL DENSITY/CALIPER

Go to Gamma Specs

 The density tool or gamma-gamma log contains both a source of gamma radiation, and a gamma detector.

The proportion of gamma rays emitted by the source and back-scattered to the source is a measure of the density of the formation in the vicinity of the source/detector combination.

Different source-detector spacing may be used, for example to maximise thin bed resolution, or to improve the accuracy of the density calibration.

AUSLOG now offer the A660 Micro Density Tool, utilising a radioactive SOURCE SO SMALL that a Radiation Licence is NOT A REQUIREMENT in many locations. The source strength is less than 1% of that used in the conventional density tool.

The MICRODENSITY has already found application with the Coal industry in Australia and Overseas, providing Geophysical logs of very high resolution which compares favorably with conventional tools. Ideal when used in combination with the A631 Gamma. Combination A619 available - Micro Density/PR/Caliper/Gamma

Usually the tool is run decentralised (often in conjunction with a single-arm caliper) and both the source and detector are collimated. These features minimise the influence of drilling mud and caving.

Caliper and Density tools have application in coal, iron ore and groundwater exploration as well as engineering and other mineral exploration.

Density
The unusually low density of coal means that it may be identified readily by the density tool. The actual value of the density is an indication of the ash content. Thin ash bands and seam splits may be easily discerned.

In iron ore exploration, ore density is a useful measure of iron content.
For groundwater exploration strata density can be related to porosity.

Engineering applications use the density log as a reliable indicator of rock strength. Factors such as weathering, fracturing and porosity can be evaluated - these seriously affect mining and excavation characteristics.

Quantitatively, density can be allied to such strength parameters as Poisson's ratio. Generally thin but often critically important strata such as volcanic ash and carbonates can be identified.

Caliper
The caliper provides quantitative information about hole-diameter. The caliper is an electromechanical unit that, by use of a spring-loaded arm, gives a measurement of borehole diameter. Knowledge of borehole diameter can be used to correct the response of the density log that is sensitive to borehole diameter. It can also provide an indication of the mechanical properties of the rocks by showing areas of caving.

Gamma
Gamma information is available by viewing A631 & A675.

Measurement of the Density downhole strata has application for:

Coal Exploration
  • The unusually low density of coal means it is readily identified.
  • The actual value of the density is and indication of Coal Ash content.
  • Thin ash bands and seam splits may be easily discerned.

    Engineering
  • Density is usually a reliable indicator of rock strength.
  • Factors such as weathering, fracturing and porosity can be evaluated - these seriously affect mining and excavation characteristics.
  • Quantitatively, density can be allied to such strength parameters as Poisson's ration.
  • Generally thin but often critically important strata such as volcanic ash and carbonates, can be identified.

    Iron Ore Exploration
  • Ore density is a measure of iron content.

    Groundwater
  • Strata density can be related to porosity.

    Legislative requirements may preclude the operation of conventional density logs water bores.









    Specifications

    Model A606 A660 A656 A659 A605
    Diameter 51 mm 51 mm 33 mm 51 mm 43 mm
    Length 2365 mm 1590 mm 1320 mm 1430 mm 2190 mm
    Weight 11 kg 9 kg 4.5 kg 8 Kg 11 Kg
    Shipping Weight 14 kg 13 kg 7 kg 12 kg 14 kg
    Pressure Rating 21000 KPa 21000 KPa 21000 KPa 21000 KPa 21000 KPa
    Temperature Rating 70'C 70'C 70'C 70'C 70'C
    Cable Cond. Required 1 or 4 1 or 4 1 or 4 1 or 4 1 or 4
    Nominal Current 120 80 30 60 150
    Power at Tool 40 VDC 40 VDC 28 VDC 28 VDC 40 VDC
    Communication DDRS232 DDRS232 DDRS232 DDRS232 DDRS232
    Detector Sensor Nal Gamma & Caliper Nal Gamma & Caliper Nal Gamma & Caliper Nal Gamma & Caliper Nal Gamma & Caliper
    Range - Density 1-3gm/cc N/A 1-3gm/cc 1-3gm/cc 1-3gm/cc
    Range - Caliper 2-10 inches 2-10 inches N/A 2-10 inches 2-10 inches
    Calibration Calibration Pits & Jig Density NA/Caliper Jig Calibration Pits & Jig Calibration Pits & Jig Calibration Pits & Jig
    Source-Detector Spacing Confidential Confidential 20,30,35,45cm as required 20,30,35,45cm as required 20,30,35,45cm as required


    Micro Density (A660) Source - Caesium 137, 3.3 MBq (90 micro Curies)
    Standard Density Source - Caesium 137, 1.85 G Bq (50 milli Curies)
    Source Storage Container - Meets IATA shipping Requirements (Not required with A660 Micro Density)