1. Soran University
Faculty of Engineering
Department of Petroleum Engineering
Drilling Engineering I [ PETE 308]
Title: Marsh Funnel Viscometer
Experiment No.: 4
Name: Muhammad Sulaimon Rasul
Group: B2
Date: 7 OCT 2019
Supervisors: Jagar Ali, Fouad Yossifi, Rawezh Najat
3. Aim
The aim of experiment is finding a drilling mud viscosity which composed of bentonite and water
using a viscometer.
Theory
Drilling mud is a mixture of water and mud (Clay) addition to some other minerals and special
chemical materials called “additives” (Kate, 1998), that used with water and mixed to maintain
well stability during the process of drilling. Sometimes mud can be non-aqueous regarding to well
condition that can be Oil-Base Mud used (Simon, 2017). A Successful drilling operation is
requiring a good quality of drilling fluid (Darley et al.,1988).
The composition that required for drilling mud is depend upon the formation stability which wells
are drill through formations with a different type of compositions that require different types of
mud composition (Simon, 2017). The liquid-based mud which usually composed of a based fluid
such as (Oil or Water) with some weighting additives such as Bentonite and Barite. (Ofi Testing
Equipment inc.,2003).
The density of drilling mud is one of the important parameters which should be first considered. It
was a definition regarding to American Petroleum Institute is matter measured per unit volume
which expressed in pounds per gallon (ppg) (Simon, 2017).
The density is one of parameters that controls formation pressure to avoid the blowout, and it
should be accurately measured in order to provide a sufficient hydrostatic pressure over the
formation pressure to avoid lost circulation (Geehan et al.,1989; Kruse, 1975).
Another important parameter that effects on mud efficiency is viscosity of mud. The viscosity is
defined as the resistance to flow. Viscosity is measured by a simple device named funnel
viscometer which has conical shape – 152 mm (6") in dimeter at the top and 305 mm (12in) is long
with the volume of 1500 cc. Also, there is a mesh screen covered a half top of the funnel which
designed to remove any impurities such as drilling cuttings. The concept is the drilling fluid should
pass through the orifice in a period of time (second) then recorded to an equation (1) to get effective
viscosity in cp(s). (Pitt, 2000).
µe = ρ(t − 25)…………………………………………………………………………….…eq (1)
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4. Apparatus and Materials
Apparatus
• Electronic Balance: Is used to measure mass in gm(s). (Figure 4)
• Cylinder: Measures water volume in (ml). (Figure 5)
• Electronic mud mixer: Is a device used to mix liquid with solid particles. (Figure 1)
• Lab Spatula: Used to mix mud and water manually. (Figure 6)
• Marsh Funnel Viscometer set: Is device used to measure a fluid viscosity especially
drilling fluid. (Figure 3)
• Beaker: is a cylindrical container used to measure volume of a liquid. (Figure 7)
• Mud balance: is a device used to measure mud density. (figure 8)
Materials
• Bentonite: Is a martial used to mix with water to create a drilling mud. (Figure 2)
• Water.
Figure 4 Electronic
Balance
Figure 1 Electronic
mud mixer
Figure 6 Lab Spatula
Figure 2 Bentonite Figure 3 Marsh Funnel
Viscometer set
Figure 5 Cylinder
(500ml, 25ml and 10ml)
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Figure 7 Beaker Figure 8 Mud balance
5. Calibration
Calibration should be executed for the viscometer for being sure if the it is working correctly or
not. However, there is a procedure for calibrating viscometer as the following steps:
1. First clean the funnel and cup of viscometer, then fill the funnel with water till 1500 ml but
a finger should be put against the bottom of the funnel.
2. Now, set a timer to 00:00 and bring a cup and put a funnel into it then remove a finger; let
all water pour inside the cup. While a finger removed timer should start.
3. Let water fill a cup till 946 ml then pause the timer directly.
4. The time should be 26±0.5 seconds, if it exceeded this range; the funnel assumed not
accurate.
NOTE: An error has been accorded about 0.13s below the 25.5s may due to late starting of timer
during the calibration which it was 25.37 seconds.
Figure 9 Marsh Funnel Viscometer: Is a set of funnel and cup which used to measure
viscosity.
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6. Procedure
1. First the volume of water must be calculated then regarding to the calculation, the amount
of water should be measured.
2. As the Bentonite has calculated in the calculations, Bentonite should measure using an
electronic balance.
3. Then take off all water inside the cup of electronic mixer and carefully turn it on.
4. Now while the mixer is working, add the Bentonite a little by little into the water to avoid
stacking of mixture.
5. After putting all Bentonite inside water while its mixing together, wait about 3-4 min till it
fully get mixed.
6. Now remove a cup from the mixer and take it to a clean beaker and put all mud into it then
clean the cup and do the same procedure about 5 more times to be sure that you get 1500
ml of drilling mud.
7. Now bring a funnel viscometer and fill it with the mud, be sure that you pour it from a filter
that fixed at the top of funnel to remove the impurities.
8. A figure should be put against the funnel outlet then pour the mud till you fill it until 1500
ml.
9. Now set a timer to 00:00 and start when the finger removed from the outlet instantly.
10. Let the mud fill the cup until 946 cc. When it gets to 946 ml stop the timer and record it.
11. Clean all used apparatus.
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8. Result and Discussion
Table 1: Experimental and Theorical Results
Materials Volume (cc) Density (ib/gal) Mass (gm)
Water 291.099 8.33 -
Bentonite Clay 8.901 20.8 22.2525
Drilling Mud 300 8.7 -
Final Mud Volume 1500 8.7 -
Viscosity of Mud = 34.32 cp
Regarding to the table 1, results are quite good theatrically. The density of mud has also measured
experimentally which was 8.7ppg on the mud balance. During the procedure, starting the timers
also may some errors about some milliseconds to one second which can be ignored. Funnel
viscometer should also fix at a point and do not move while the mud pouring to the cup and also
should has no slops as well to avoiding any kind of errors. The mud viscosity is directly
proportional to the mud density in other words depend on the concentration of solid particles.
However, the mud viscosity will directly have effect on the flow rate of mud and also effect on
mud pumps, in case of high viscosity mud requires more powerful pump.
Conclusion
Performing this kind of experiment’s make students engage more and gain ability to generate
drilling mud as recommended and be able to measure its viscosity by a simple technique using
funnel viscometer and an equation for finding effective viscosity.
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9. References
Darley, H.C.H. and Gray, G.R. (1988): The composition and Properties of Drilling and
Completion Fluids. 5th Ed. Gulf Publishing Company, Houston Texas. pp 110.
Geehan, T. and Mc Kee.A. (1989): Drilling Muds. Monitoring and Managing it. Oilfield
Review 1(2), pp 41-52.
Growcock, F. and Harvey, T. (2005) „Drilling Fluids‟ in ASME, Shale Shaker Committee.
Drilling Fluids Processing Handbook. Oxford: Gulf Professional Publishing, pp. 15-68.
Herzon, S. (2017). LABORATORY PRACTICAL REPORT ON THE FACTORS THAT
AFFECTS THE PROPERTIES OF THE DRILLING MUD DURING DRILLING
PROCESS. [online] academia.edu. Available at:
https://www.academia.edu/35123831/LABORATORY_REPORT_ON_THE_FACTORS
_THAT_AFFECT_THE_PROPERTIES_OF_DRILLING_MUD [Accessed 27 Sep.
2019].
Kate, V.D. (1998): Drilling Fluids, Mud Pumps and Conditioning Equipment.
Kruse, C.F. (1975): Lessons in Rotary Drilling, Unit II-Lesson 2 “Drilling Mud”. 12th
Edition. Published by Petroleum Extension Service Industrial and Business Training
Bureau Division of Extension, The University of Texas. Pp 1-47.
M.J. Pitt. (2000): The Marsh Funnel and Drilling Fluid Viscosity: A New Equation for
Field Use. 15th ed. Leeds: Society of Petroleum Engineers, pp.1-4.
Ofi Testing Equipment, Inc. (2003). Extreme Pressure and Akaranta, O. and Osuji, L.C.
(1997): Carboxylmethylation of orange mesocarp Cellulose and its utilization in Drilling
mud formulation. International Journal for Physics, Chemistry and Technology of
Cellulose and Lignin 31, pp 193-198.Lubricity Tester Instruction Manual.
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