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Lithodensity gamma-gamma logging tool


The tool has the following modifications by max operating temperature T max and upper value of borehole hydrostatic pressure Pmax :
 by temperature: 120, 150, 175 °С,
 by pressure: 80, 100, 120, 140 МPа.
Designed to measure rocks bulk density and determine rocks photoelectric absorption index.

Used for logging of open oil and gas holes filled with any mud; the tool operates with a three-conductor carrying logging cable up to 7000m long and log recorders that provide for command transfer and data receipt in “Manchester-2” code.

 well sections and lithological changes correlation;
 detailed lithological identification;
 stratigraphic studies;
 reservoir properties identification/refinement;
 rocks mineral composition identification/refinement.

The sonde station contains a chamber for fast neutron encapsulated source 137Cs with collimated radiation output and three gamma ray scintillation detectors with directional sensitivity diagram.

 Measured parameters Measurement range Error
Rocks bulk density 1.7÷3.0 g/cm3 ±1.5 % in the range
1.7÷2.0 g/cm3
±1.2 % in the range
2.0÷3.0 g/cm3
Photoelectric absorption index 1.5÷6.0 barn/electron ±0.25 barn/electron

 General specifications
Tool length, mm 3500 not more than
Tool diameter, mm 80 not more than
Tool weight, kg 70 not more than
Power supply:
supply voltage, V
supply frequency, Hz


Drive control multiple, at the command from the surface  
Arms opening (closing) time, min 2 not more than
Borehole diameter, mm 110÷350  
Logging speed, m/hr 200  
Combinability bottom  
Location in the borehole clamped