Propagation Resistivity and Gamma Ray

A propagation resistivity tool is an advanced instrument used in drilling operations to measure the electrical properties of geological formations surrounding the wellbore. These tools employ electromagnetic waves to determine the resistivity of rocks and fluids, providing essential data for reservoir characterization.

 

Working Principle

 

The tool emits electromagnetic signals from a built-in transmitter. These signals propagate through the formations, and their attenuation and phase shift are recorded by one or more receivers placed at different distances.

 

• Low Resistivity: Indicates the presence of conductive fluids such as salt water.

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• High Resistivity: Suggests the presence of hydrocarbons or non-conductive rocks. Data is obtained at multiple frequencies and spacings to increase resolution and accuracy at different depths.

 

Key Features ​

 

• Real-Time Measurements: Provides immediate data while drilling. ​

 

• High Resolution: Detects subtle changes in subsurface properties. ​

 

• Multi-Frequency and Spacing: Allows for measuring resistivities over a wide range and obtaining greater detail of the formations. ​

 

• Integration with MWD/LWD Systems: The tool can transmit data to the surface using telemetry systems, such as positive pulse or electromagnetic.