Drilling Engineering-I-Lab

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

2. Experiment # 01:
• Objective
• To find the density of different samples of drilling mud
using Mud balance.
5/5/2021

3. Apparatus
• Mud Mixer
• Barite
• Salt
• Water
• Measuring cylinder
• Beaker
• Mud Balance
• Weighing Balance
5/5/2021

4. Related Theory
• Mud Balance:
• It consists of a graduated beam with a bubble level and a
weight slider along its length and a cup with a lid on one end.
• The cup is used to hold a fixed amount of liquid so it can be
weighed.
• A slider-weight can be moved along the beam, and a bubble
indicates when the beam is leveled.
• Density is read at the point where the slider-weight sits on the
beam at level.
• Calibration is done using a liquid of known density (often
water) by adjusting the counter weight.
• Typical mud balances are not pressurized, but a pressurized
mud balance operates in the same manner.
5/5/2021

5. Mud Balance
5/5/2021

6. 5/5/2021

7. • Bentonoite:
• The mineral bentonite can be found all over the world. It is
formed from weathering volcanic ash. It has some exceptional
properties:
• when stirred into water, it demonstrates a so-called thixotropic
reaction. It reacts as a fluid when mechanically stressed, for
example shaken or stirred. However, it hardens in quiescent
condition because its viscosity increases.
• The most common use of bentonite is in drilling fluids.
• The bentonite in the flush fluid lubricates and cools the cutting
tools while protecting against corrosion.
• As the drilling fluid generates hydrostatic pressure in the
borehole, it hinders fluid and gas penetration. The drilling
liquid conveys the drill cuttings to the surface. When the purge
pumps have idle periods, the thixotrophy of the bentonite
hinders the stone material from dropping back into the drilled
shaft.
5/5/2021

8. Barite:
• Barite is the primary, naturally occurring, barium-based
mineral.
• The chemical formula for barite is BaSO4. It has a high
specific gravity of 4.50 g/cm3.
• The overwhelming majority of the barite that is mined is used
by the petroleum industry as a weighting material in the
formulation of drilling mud.
• Barite increases the hydrostatic pressure of the drilling mud
allowing it to compensate for high-pressure zones
experienced during drilling.
• The softness of the mineral also prevents it from damaging
drilling tools during drilling and enables it to serve as a
lubricant.
• The American Petroleum Institute (API) has established
specifications for the use of barite in drilling mud.
5/5/2021

9. Density and Specific
Gravity
Material Specific Gravity g/cc Density PPG
Water 1 8.33
Bentonite 2.5 20.3
Barite 4.5 35
5/5/2021

10. Procedure
1) A mud balance can be calibrated with water or other liquid of
known density by adjusting the rider and making the mud balance
level. Positive or negative error is noted down and is adjusted for
subsequent readings.
2) After calibration, completely fill the cup with completely agitated
mud sample to be tested.
3) Put the lid on cup and rotate until firmly seated, making sure that,
some mud must spill through the lid hole.
4) Wipe away the spilled mud from the outside of the cup and lid.
5) Place the mud balance on its position in the box.
6) Move the rider until the graduated arm is leveled, as indicated by
the bubble level.
7) Note the density reading and remove the error if present. Report
final density in g/cc or ppg.
5/5/2021

11. Experiment Demonstration
5/5/2021

12. Mud Balance Calibration
5/5/2021

13. Observation and
Calculations
• Barite + Water Solution :
• Mass of Barite : ___________ grams
• Volume of Water : _____________ml
• Mud Density : ____________ lbs/gal + Error (If needed)
• Specific Gravity : __________ g/cm3 + Error (If needed)
• Water + Salt Solution :
• Mass of Salt : ___________ grams
• Volume of Water : _____________ml
• Solution Density : ____________ lbs/gal + Error (If
needed)
• Specific Gravity : __________ g/cm3 + Error (If needed)
5/5/2021

14. Precautions
• It is essential that all part of mud balance should be kept
clean if accurate results are to be obtained.
• Calibration is mandatory before using mud balance.
• All air bubbles which may trap in the cup, must be
eliminated.
• Wear relevant personal protective equipment (PPE)
where needed.
5/5/2021

15. Viva Voce
1. List any five (5) very important functions of the drilling
fluid?
2. What requirements should a drilling fluid meet?
3. What will be the effect of increasing the amount of barite
in the mud?
5/5/2021