Definition - What does Microresistivity Log mean?
A Microresistivity Log is a type of a log that is associated with the flushed zone resistivity that is recorded by a device known as a wireline electrode. This log is a scaled-down version of the logs related to this technology. A wireline electrode device is installed on a pad, and the device is pushed against the wall of the borehole, with the pad side on the inner side. There are other available logs such as microlaterolog, microlog, ES log, microspherical log, proximity log and microcylindrical log to name a few. A Microresistivity Log is far more focused on the borehole conditions.
Petropedia explains Microresistivity Log
When a borehole is drilled into the earth's surface, different kinds of evaluation tests are conducted to analyze the rock formation. These tests help drilling engineers to better understand the various aspects of the formation. A microresistivity device such as a wireline electrode is used in the analysis of the flushed zone. This device helps in the measurement of the resistivity of the zone and also finds the mudcake in the region. The thickness and resitivity of the mudcake can affect the microrestivity readings. Therefore, the wireline electrode device is fixed with a pad, because the pad assists in avoiding the effects. The device is then lowered inside the borehole, with the pad carrying the electrodes. The pad is pressed facing the formation and the current flows from the electrodes to the mudcake, after which it reaches the flushed zone.
The Microrestivity Log has varied technologies ranging from microlog to express MCFL microrestivity techniques. A Microresistivity Log only works in an open borehole.