What Is Mud Resistivity
The resistivity of the mud is extrapolated from its electrical conductivity, measured by this field proven toroidal coil sensor, to provide: Resistivity IN, Resistivity OUT, Indication of salt layers, Indication of fluid influx into the wellbore and Indication of overpressured zones.See also: Mud Temperature Sensor
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| Mud Resistivity Sensor. |
Description
The sensor measures changes in drilling fluid electrical resistivity, caused by changes in the salinity of the fluid. Mud salinity changes can occur when drilling through bedded salts or salt domes, when passing through fault zones, and in zones of transition to abnormal pressures (Reference: Kkudskmark6).Principle of Measurement
The conductivity of the fluid is determined by measuring the current induced in the secondary of a pair of toroidal coils, the coupling of which is ensured by the fluid itself. The magnitude of the induced current is proportional to the electrical conductivity of the mud, which is directly related to the salinity of the water content. The toroidal coils are encapsulated in a plastic frame together with a temperature compensating thermistor. This system, which ensures that the electrodes do not come into contact with the mud, enables accurate and linear measurement of conductivity from 0 to 300 milliSiemens.Output
Display, output and recording of the measurements is determined by the ALS computer processing equipment, according to a wide choice and range of formats.See also: Mud Flow Sensor
Technical Specifications
Measurement method Toroidal coils (no electrodes)Signal type Analogic
Output signal 4 - 20 mA
Range 0 - 300 milliSiemens / cm
Sensitivity 1 milliSiemen / cm
Accuracy + 5% of full scale
Operating voltage 24 V
Calibration method Simulator with factory set calibration graph
Safety standard Intrinsically safe
Safety module MTL 7087+
Certification EEx ia IIC T6
Installation location In suction pit and shale shaker header box