Changes

===Induction===

===Induction===

Induction tools use electromagnetic coils to establish magnetic fields that excite current flow in the formation, which in turn excites secondary magnetic fields and current flow in receiver coils in the tool. This principle of exciting magnetic fields allows induction tools to measure resistivity without the requirement of a direct electrical connection to the formation. This feature permits the tool to be used in nonconductive muds. Different transmitter and receiver arrays allow focusing of the measurement for different vertical resolution and depths of investigation. A typical presentation of a dual induction log is shown in Figure 1.

Induction tools use electromagnetic coils to establish magnetic fields that excite current flow in the formation, which in turn excites secondary magnetic fields and current flow in receiver coils in the tool. This principle of exciting magnetic fields allows induction tools to measure resistivity without the requirement of a direct electrical connection to the formation. This feature permits the tool to be used in nonconductive muds. Different transmitter and receiver arrays allow focusing of the measurement for different vertical resolution and depths of investigation. A typical presentation of a dual induction log is shown in [[:file:basic-open-hole-tools_fig1.png|Figure 1]].

===Laterologs===

===Laterologs===