The document describes an experiment focused on mud dilution in petroleum engineering, aiming to decrease the mud weight by adding water. It includes methodologies for calibrating equipment, procedures for mixing materials, and discussions about the implications of changing mud density. The document also addresses potential errors during the experiment and provides insights into the relationship between mud density and drilling performance.

1. Petroleum engineering
Faculty of Engineering
Koya University
Drilling Engineering
Laboratory
Experiment No. 3: Mud Dilution
Date: Dec. 12th
2017
Supervised By: Prepared By:
Mr. Pishtiwan Jarjis Muhammad
Mr. Muhammad Group: B

2. Mud Dilution Experiment Jarjis Muhammad
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Contents
Subject Page
Aim 1
Introduction to Experiment 2
Theory 3
Mud Balance Calibration 4
Procedure 5
Discussion 6
References 8

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Aim of the experiment
-Decreasing mud weight (density of mud) by adding Water
(H2O) to the mud.

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Introduction to Experiment
Beaker Baroid Mud Balance
Weight balance Device Mixer
Container Syringe

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Theory
The mud weight is generally designed such that the borehole
pressure opposite permeable (and in particular hydrocarbon
bearing sands) is around 200-300 psi greater than the formation
pore pressure. This pressure differential is known as the
overbalance. If the mud weight is reduced the overbalance
becomes less and the risk of taking a kick becomes greater. It is
therefore essential that the mud weight is continuously
monitored to ensure that the mud that is being pumped into the
well is the correct density. If the mud weight does fall for some
reason then it must be increased to the programmed value
before it is pumped downhole. When the mud is being treated
to improve some property (e.g. viscosity) the first stage is to
dilute the mud with water (water-back) in order to lower the
percentage of solids. Water may also be added when drilling
deep wells, where evaporation may be significant. During these
operations mud weight must be monitored and adjusted
carefully.

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Mud balance 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 vial should be centered when the rider is set on
8.33. If not, add to or remove shot from the well in the end of
the bream.

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Procedure:
1. First we weigh bentonite (22.455gm)
2. Then we prepare 400 cc of water.
3. Then we calibrate the Baroid mud balance by density of
water.
4. After that we mix the bentonite and water by mixtures
5. Next we measure density of mud by Baroid
6. Next we measure the additive water (222.22 cc).
7. Then we mix it with the prepared mud by mixture.
8. Finally we find the final density of mud.

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Discussion:
1. Why we need to decrease the density of the drilling
mud?
Ans. we need to decrease the mud density because we
need to avoid several problems such as:
A. Mud circulation loss
B. Circulation low velocity
C. High viscous mud
D. Rate of Penetration (ROP) (decreases horsepower
required to circulate)
E. Avoid poor log quality ( rare cases)
F. Hole cleaning problems
2. Can we use other liquids instead of water?
Ans. Yes, we can use other liquids such as oil if we
have water sensitive formation. Or the main mud is
oil-based mud.

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3. What happened if the water temperature is high?
Ans. If the water temperature is high our calculations
will be wrong because the relationship between density
and temperature is direct relationship, so then we need
to use correction chart to measure actual density of
water. Here is the water density & temperature chart.
Water density & temperature chart. (fig.1)
4. What are the errors that we faced in this experiment?
Ans, 1- When we weigh bentonite some of the
bentonite will be lose as a light powder by air. So it will
cause the measurements.
Avoid. To avoid this error we need to add a little more
bentonite. And we must do this experiment carefully.

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2- Human errors.
Avoid. To avoid this error we must do this experiment
attentively, and do the experiment again if necessary.
3- If the quality of bentonite is bad then our
calculations will not be accurate.
Avoid. For avoid this error we need to get a good
quality of bentonite (API accepted quality).
5.

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6. What is mud window and how can we use it for our
mud calculations?
Ans. Mud window is a graph between depth of the
hole and mud weight. With several pressure gradients
such as (pore pressure, fracture pressure, collapse
pressure) and lithostatic. We can use it for our
calculations of mud density; we need to try adjusting
mud density between fracture pressure and pore
pressure. To avoid well bore problems while drilling.
Here is a sample of mud window:
A sample of mud window (fig.2)

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References:
1. Adam T. Bourgoyne Jr., Keith K. Millheim, Martin E.
Chenevert, and F. S. Young Jr.: “Applied Drilling
Engineering,” SPE Textbook Series, 1991.
2. Max R. Annis and Martin V. Smith: “Drilling Fluids
Technology,” Exxon Company, U.S.A., 1996.