PETROLEUM ENGINEERING LABORATORY
EXPERIMENT ON DENSITY
19TH JANUARY, 2018
Density, or mass density can be appropriately defined as the mass per
unit volume of a material substance. Density is represented using the character “?”. It
is a letter in the Greek alphabet called “Rho”. However, it is sometimes
represented using the Latin letter “D”. Density is obtained by dividing the
mass of the substance by it’s
volume. Mathematically, represented below:
? = m / v
Density, is a very important property when it comes to drilling fluids.
The pressure exerted by a static pressure(i.e the hydrostatic pressure
of the drilling fluid is dependent on the density of the drilling fluid.
Therefore, the proper control of the density of the drilling fluid will in turn
control the hydrostatic pressure. The hydrostatic pressure of the drilling
fluid has to be greater than the formation pressure, in order to prevent the
uncontrollable flow of formation fluids into the wellbore.
This experiment determines the density of two different samples of
starting point for drilling fluid pressure control is mud density.
density of a substance, is it’s mass per unit volume. It is represented with
the Greek character “Rho”- ?. The Density of a drilling fluid needs to be monitored closely
and adjusted in order to control the pressure properties of the fluid to
maintain wellbore stability.
this experiment, density is determined using a four scale mud balance.
It is a standout amongst the most delicate and
exact field instruments accessible for deciding the thickness or weight-per-unit-volume
(particular gravity) of penetrating liquids.
exceptional favorable position of this Mud Balance is that the temperature of
the example does not tangibly influence the precision of readings. A high
effect plastic case ensures the adjust amid transport and gives a protected
base in its working position.
Balance is developed so the settled volume container toward one side of the bar
is adjusted by a settled stabilizer at the contrary end, with a sliding weight
rider allowed to move along the graduated scale. A level bubble mounted on the
beam indicates when the system is in balance.
mud balance is built with a beam graduated into four scales:
per cubic foot
per square inch per 100 feet of depth
scale ranges are from:
– 23.0 lbs/gal (ppg)
– 2.72 specific gravity (s.g)
– 1190 psi/1000f
scale Mud balance
CALIBRATION OF SCALE
Fill the cup with water first, the close the lid
and wipe the top of the lid and the body of the cup itself dry with a napkin or
a soft cloth.
Start the rider off at 8.3ppg or 10s.g, then move
until the instrument is in balance. When the level bubble on the beam is at the
center of the two vertical lines, then the system is in balance.
If the reading is below 8.3ppg, add the difference the
between 8.3ppg and the reading to the mud weight. If the reading is higher than
8.3ppg, subtract the difference from the mud weight after a test is made.
Place the mud balance on a leveled surface.
Put the test liquid into the cup.
Cover the cup with it’s lid and turn it clockwise
to set it in place. Make sure some of the test fluid is expelled from the
little hole on top of the lid, this shows that the cup is full and it will also
free any trapped air or gas.
Cover the hole on top of the lid and wipe the lid
and the body of the cup with a dry cloth.
Then, place the mud balance on the knife edge and
move the rider along the scale until the bubble indicates that the system is
Obtain the mud weight by reading the value on the
Specific gravity (s.g)
Sample 1 is a water based mud consisting of Water and Bentonite. Sample
2 is a water based mud consisting of Water, Bentonite and Barite. From the
results above, it is shown that the density of sample 2 is greater than the density
of sample 1. Barite is a weighting material used in the field to increase mud
density, and from this experiment, it can be observed that the sample with
barite has a greater mud weight than the mud samples with only water and
Bentonite. The Barite, increased the mud weight of sample 2.