Logging tool

Drilling Fluids & Logging

A logging tool is a downhole instrument lowered into the wellbore to measure the physical properties of the rock formation and the fluids it contains. These tools use various physics principles—electrical usage, acoustic waves, or radioactive sources—to derive data such as porosity, permeability, water saturation, and rock type.

Tools can be conveyed via wireline (after drilling) or built into the BHA as LWD (Logging While Drilling) tools. The choice depends on the well trajectory, risk of stuck pipe, and the need for real-time decision-making. Standard suites include Gamma Ray, Resistivity, and Density/Neutron logs.