module 6-resistivity Flashcards
current can be produced by using either:
Electrode resistivity tools
Induction resistivity tools
Ro?
Resistivity of non shaky rock saturated with formation water
Resistivity high or low?
SS, 20 porosity, filled with salt water
filled with HC
filled with fresh water
LOW
HIGH
HIGH
3 types of electrode logs?
E logs
Laterologs
Micro Resistivity logs
Induction resistivity tools
coils to induce a current and measure the formations conductivity
An electrode measures?
shallow investigative device that measures resistivity of the invaded zone
An induction device measures?
deeper zones, uninvaded zones
Name 3 Electrode logs? (measures resistivity)
Normal logs
Lateral logs
laterologs
Name 2 induction logs? (measures conductivity)
Induction electric log
Dual Induction log
Micro-resistivity logs (Caliper) identify what?
Permeable zones
The drilling fluid invades porous and permeable zones.
What is the Depth of investigation?
a combination of 2 resistivity measurements of various depths from the pad (micro log), which is pressed against the borehole wall
What is a Microlog?
a pad type resistivity device that primarily detects mudcakes
What does the Micro-inverse curve investigate?
shallow depth resistivity of the mudcake
What does the Micro-normal curve investigate?
shown as dotted curve and shows deeper, flushed zone, which reads formation and mud cake resistivity values
What are the 2 ML separations and what do they mean?
Positive Micro normal > micro inverse
means presence of a permeable due to build up of mud cake
Negative
Shale zones are indicated by no separation or negative separation
