Wireline logging can address questions about:
• Mechanical condition of the well.
• Fluid movement between zones.
• Design and evaluation of stimulation treatment.
• Reservoir management.
Collar Locator
• It shows the location of casing collars, where the thickness is high.
• It is run with perforating guns or plugs.
• In a magnetic CCL, when the unit moves through collar, the increase in metal thickness disturbs the magnetic field and causes a blip to be recorded.
Temperature devices
• The thermometer uses an electrical bridge with an exposed sensing wire as the fourth arm.
• Temperature is affected by heat flow and fluid expansion.
• Temperature log may be run under either dynamic and static conditions.
Spinner Flowmeter
• Based on propeller movement.
• Rotation rate and direction are determined.
Gradiomanometer
• Gradiomanometer is based on pressure measurement at two fixed points.
• Good for identifying gas entry point and locating standing water levels.
• It can also be used to calculate water hold up.
Noise devices
• Noise log is a recording at various points in the well of the amplitude of the noise generated by moving liquid or gas using an assembly of microphone, amplifier and a speaker.
Caliper
• Measures any change in the borehole due to solid deposition.
• Multi-arm caliper can measure metal loss due to corrosion or erosion.
• They can be used in openhole completions.
Combination Tool
• CCL.
• Thermometer.
• Manometer.
• Caliper.
• Gradiomanometer.
• Flow meter.
Cement Evaluation Tool (CEV)
• For identifying mud channels.
• Consists of 8 ultra sonic transducers arranged helically over 2 ft.
• Each transducers in turn transmits a signal, then measure the signal decay rate.
• Sonic decay rate is related to the compressive strength of the material around the casing.