This document describes an experiment to measure the resistivity of drilling mud and mud cake using a resistivity meter. The objectives are to measure the resistivity of drilling mud and understand how factors like salt concentration, temperature, and solid content affect resistivity. The procedure involves filling a sample cell with mud, measuring its temperature and resistivity using a resistivity meter, then calculating the salt concentration using a nomograph. Precautions are taken to avoid air bubbles and ensure safety.

1. Drilling Engineering-I
Pet-E-211L
Lab Instructor :
Engr. Muhammad Awais Qureshi
Department of Petroleum &
Gas Engineering 5/5/2021

2. Experiment # 11
• Objective:
1) Measurement of resistivity of drilling mud and mud cake
using resistivity meter.
5/5/2021

3. Apparatus
• Resistivity Meter
• Testing Drilling Mud Balance
• PPE’s (Personal Protective Equipments)
5/5/2021

4. Related Theory
• The resistivity of a drilling mud is influenced by the dissolved salts
(ppm) or (gpg, grain per gallon) in the water portion and the insoluble
solid material contained in the water portion.
• Unlike metals, the resistivity of a solution decreases as temperature
increases.
• It is necessary to measure resistivity because the mud, mud cake, mud
filtrate resistivity exert a strong effect on the electric logs taken in that
mud.
• The mud resistivity varies greatly from the actual resistivity values due
to the various factors encountered in the actual operation
• Resistivity Meter
• Resistivity Meters are electronic meters used to measure
the resistivity of fluids, slurries or semi-solids.
5/5/2021

5. Resistivity Meter
5/5/2021

6. Measurement Procedure
1) Remove the sample cell from the resistively meter and
fill it with the test sample.
2) When filling the cell with filtrate, fill and discharge the
sample several times before the final filling.
3) Make sure there are no air bubbles in the sample.
4) Reattach the sample cell onto the pains on the meter.
5) Insert the temperature probe in the wall in the sample
cell, set the mods switch to temp and allow the
temperature reading to stabilize. This will take at least
three min if meter and samples are not at room
temperature.
5/5/2021

7. 6) Set the mode switch to RES, read and record the
resistively in ohmmeters.
7) Remove the sample cell and clean with distilled water.
If necessary, a pipe cleaner and mild soap (no solvents)
can be used to clean the bore of the cell.
8) Using the monographer, convert resistively values to
concentrations of chlorides.
5/5/2021

8. Demonstration
5/5/2021

9. Observation and
Calculations
5/5/2021
Temperature = _______________ ⁰ F
Resistivity = _______________ Ωm
Nacl concentration = _________________ Kppm

10. Nomograph of Nacl Solution-
Concentration Measurement
5/5/2021

11. Precautions
1. Make sure there are no air bubbles in the sample.
2. Follow the general safety instructions during
experiment .
3. Wear relevant Personal protective equipment.
5/5/2021

12. Viva Voce
1. Explain the parameters which influence the resistivity of
a drilling mud?
2. Explain the importance of drilling mud resistivity?
5/5/2021