This document summarizes a student's fluid mechanics lab experiment on measuring mud density. The aim was to learn how to use a mud balance apparatus to measure the density of drilling mud and see how density changes with the addition of barite. The student first prepared a bentonite mud and measured its density. Barite was then added to increase the mud density, which was remeasured. Understanding mud density is important for maintaining proper hydrostatic pressure to prevent fluid influx from formations during drilling.

1. KOYA UNIVERSITY
FACULTY OF ENGINEERING
SCHOOL OF PETROLEUM AND
CHEMICAL
FLUID MECHANIC LAB
NAME OF EXPEREMENT:
Mud Density
NAME OF STUDENT:
Kamal Abdurahman
Group: B
SUPERVISED BY: Mr.Pshtiwan Jaf

2. Aim of experiment:
1.To know how to use mud balance apparatus.
2.To know the change in density after adding barite by using water.
3.To recalculate the density of the mud which is given.

3. Introduction
Density or weight of a given volume of liquid is determined by
using a mud balance. The arm is graduated and permits accurate
measurements to within +- 0.1 pounds per gallon or +- 0.01
specific gravity. The mud balance is constructed so that the fixed
volume cup at one end is balanced by a fixed counterweight at
the opposite end, with a sliding weight rider free to move along on
the beam indicates when the system is in balance.

4. Theory
The density of the drilling fluid must be controlled to provide
adequate hydrostatic head to prevent influx of formation fluid, but
not so high as to cause loss of circulation or adversely affect the
drilling rate and damaging the formation.
Normal pressure gradiant by water is equal to(0.433 psi/ft) and
equal to 433 psi/1000 ft.
A mud balance,also known as a mud scale is adevice used to
measure the density(weight) of drilling fluid,cement or any type of
liquid or slurry.
There is no reliable visual method of determining the density of
drilling mud, the mud balance is the most reliable and simple way
of making the determination.

5. Apparatus of experiment
The instrument consists of a constant volume cup with a lever
arm and rider calibrated to read directly the density of the fluid
in PPG(water 8.33),pcf(water 62.4),specific gravity (water=1)
and pressure gradient in psi.

6. Calibration
1.Remove the lid from the cup ,and completely fill the cup with
water.
2.Replace the lid and wipe dry.
3.Replace the balance arm on the base with knife-edge resting on
the fulcrum.
4.The level via l should be centered when the rider set on
8.33ppg.If not, add to or remove shot from the well in the end of
the beam.

7. Procedure
1.Remove the lid from the cup, and completely fill the cup with the
mud to be tested.
2.Replace the lid and rotate until firmly seated, making sure some
muds expelled through the hole in the cup.
3.Wash or wipe the mud from the outside of the cup.
4.Place the balance arm on the base,with the knife-edge resting
on the fulcrum.
5.Move the rider until the graduated arm is level,as indicated by
the level vial on the beam.
6.Noted down the mud temperature corresponding to density.
7-after we are prepared bentonite mud we put in this mud
barite(weight 25.8463gm) and after that we are rerecorded the
density of the new mud by mud balance.

8. Mud Preparation
V1 W1 + V2 W2 + ….. = Vf Wf
V1 + V2 + …… = Vf
Where:
V1 : Volume of the first material to be mixed.
V2 : Volume of the second material to be mixed.
Vf : Total volume of the mud.
W1 : Density of first material.
W2 : Density of second material.
W3 : Density of the mud.

9. Discussion
-We must be clean all the device before our works because if they
are dirty ,they will be cause error in our experiment.
-If the water is not clean(dirty)to prepare this mud we have some
error to equilibrium this balance,you must balanced this mud
balance with the water(standard solution)in first stage and after
that you balanced the bentonite mud with respect to density of the
water and we put this mud (barite) to increase the density of the
mud (to controlled the formation).
-In this experiment we want to recalculate the density of the
mud,first we weight 17.041gm of the bentonite in the weight
balance and mixed it with 493.19cc of water,then we put it in the
mixture tool,in fact we could not make the mud balance our
bentonite in the lab was bad ,so our result was mistaked.
-If the mud was mixed didn't bad,we must find the mud density by
the mud balance. After the mixture we must weight 25.8463gm of

10. barite and put in to the mixture of the bentonite and water(mud) in
the mixture tool,after this mixture we find its density by the mud
balance too.From that we know the difference between both
density.
Q/Why are we increase density of this mud?
A/In this test we are weightining this mud by adding the
barite(high density) to increase the density of mud(bentonite mud)
,the useful of this increasing mud to contolling the adequate
hydrostatic head to prevent in flux of formation fluids .

11. Pressure
Ph = MW × TVD × 0.052
Pr = 0.433 × TVD
Pf = fracture gradient x TVD
Where:
– Ph: is mud hydrostatic pressure in psi.
– Pr: is reservoir pressure in psi.
– Pf : is fracture pressure in psi
– TVD: is true vertical depth in ft.
– MW: is mud weight (density) in ppg.
– 0.433: is fresh water pressure gradient in psi/ft.

12. Pressures
• To avoid the risk of kick (blowout), hydrostatic pressure should
be greater than the formation (reservoir) pressure.
• To avoid the risk of formation fracturing (fluid losses),
hydrostatic pressure should be less than the fracture pressure.
Pr < Ph < Pf

13. The Standard one of This Test

14. Reference
-www.scribd.com/mud balance experiment.
-https://www.google.iq/#q=introduction+to+mud+density.