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Standard electrical logging slim tool ESK-48


The tool has the following modifications by max operating temperature T max and upper value of borehole hydrostatic pressure Pmax  :
  by temperature: 120°C,
  by pressure: 80 MPa.

Designed for apparent resistivity measurement ρaof rocks crossed by a borehole using conventional logging (CL), resistivity measurement, self-potential (SP) and SP gradient (ΔPS). 

Used for logging of open holes filled with water-base mud; the tool operates with a three-conductor carrying logging cable up to 5000 m long and log recorders that provide for command transfer and data receipt in “Manchester-2” code.

 reservoir identification in oil and gas wells section;
 formation apparent resistivity evaluation;
 reservoir saturation evaluation.

The measuring equipment contains five electrodes placed on a hard electrically insulated housing. Switching and electrode power supply arrangement provide for ρa measurement by standard lateral sondes A2M0.5N and N0.5M2A, normal sonde A0.5M2N, resistivity measurement and also SP and ΔSP.

 Measured parameters Range Error
ρa A2.0M0.5N 0.1÷1000 Ohm·m ± (5+30/ρla+2 ρau)% *
ρa N0.5M2.0A 0.1÷1000 Ohm·m
ρa A0.5M2.0N 0.1÷200 Ohm·m
Resistivity meter 0.03÷20 Ohm·m ± (10+30/ρla+2 ρau)% *
M∞N(SP) from +1.25 to -1.25 V ±1 mV
M∞N (ΔSP) from +250 to -250 mV ±1 mV

 General specifications
Tool length, mm 7000 not more than
Tool diameter, mm 48 not more than
Tool weight, kg 35 not more than
Power supply:
supply voltage, V
frequency, Hz


Borehole diameter, mm 56÷200  
Logging speed, m/hr up to 2000  
Combinability feed-through  
Location in the borehole free  


* ρu - upper limit of ρa , ρl - lower limit of ρa