Drilling Fluid Engineering PH Lab Drilling Lab

1. 1
Koya University
Faculty of Engineering
Petroleum Engineering Department
Third stage
Drilling Lab.
Lab No.: 9
Prepared by : Sarwar Salam Abdulrahman
Group: B
Date of Experiment: - Mar. 31st
2016
Submitting Date: -Apr.06 th
2016
Supervised by: Mr Mohammed-Mr Pshtiwan

2. Drilling Lab. Hydrogen Ion Index (PH)
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During this particular experiment we are trying to determine
Hydrogen Ion Index which is well known as PH, pH measurement has
a wide variety of industrial applications in virtually every industry.

3. Drilling Lab. Hydrogen Ion Index (PH)
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pH is a measure of the acidity or alkalinity of a water solution. The
acidity or alkalinity of a water solution is determined by the relative
number of hydrogen ions (H+) or hydroxyl ions (OH- ) present.
Acidic solutions have a higher relative number of hydrogen ions,
while alkaline (also called basic) solutions have a higher relative
number of hydroxyl ions. Acids are substances which either
dissociates (split apart) to release hydrogen ions or react with water to
form hydrogen ions. Bases are substances that dissociate to release
hydroxyl ions or react with water to form hydroxyl ions.
In water solutions, the product of the molar concentrations1 of
hydrogen and hydroxyl ions is equal to dissociation constant (Kw).
Knowing the value of the constant and the concentration of hydrogen
ions makes it possible to calculate the concentration of hydroxyl ions,
and vice versa. At 25°C, the value of Kw is 10-14 (see Figure 1).
Figure 1(Kw in acids and basis) (Emerson, 2010)

4. Drilling Lab. Hydrogen Ion Index (PH)
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Dissociation of water:
H2O ⇔ H
+
+ OH
-
• For pure water [H+] = 10
-7
moles/L
[ ] denotes moles/L
• pH = - log[H+] • For pure water pH = 7
[H+] X [OH-] always equals 10-14
• log [H+] + log [OH-] = -14
*PH Scale:
The control of many drilling fluid system properties is dependent on
pH (the detection and treatment of contaminants such as cement and
soluble carbonates). pH also affects the solubility of many thinners
and divalent metal ions such as calcium and magnesium, and
influences the dispersion or flocculation of clays.
The relative acidity or alkalinity of a liquid is conveniently expressed
as pH. Defined as the negative logarithm (to the base 10) of the
hydrogen-ion concentration, pH units decrease with increasing acidity
by a factor of 10.

5. Drilling Lab. Hydrogen Ion Index (PH)
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The Lab Model Digital pH/Ion Meterhas a milli-volt range of +/-
1000mV and easily converts from 115- to 230-volts AC power by use
of a conveniently mounted switch. The unit provides accuracy and
readability of 0.01 pH.
The automatic temperature compensation (ATC) range on this
instrument runs from 0° to 100° centigrade. The ATC probe (included
with meter) plugs into the front panel of the meter and automatically
adjusts the readout to measure temperature variations in the fluid. The
analog recorder output may be continuously used in conjunction with
a recorder to display and record the pH measurements.
Laboratory Bench-type pH Meter provides stable, accurate
measurements in pH, mV and temperature. Built-in memory function
stores up to 50 pH, mV or relative mV readings with corresponding
temperature. This meter is so easy to use; you'll be ready to take
readings in minutes!
Figure 2 (PH meter) (Digital PH meter.2014)

6. Drilling Lab. Hydrogen Ion Index (PH)
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Before we start doing this experiment we have to test for pure water
which it has a PH of 7.03, the pre-test check will be performed and
then check if you get 7.03 or not if not, if you get any other number
you need to add or subtract the difference from the real value.
For example we got a correction factor as to be 2.02 in our
experiment, so we will subtract 2.02 from the real data of PH
measurement of the mud to be 5.9.

7. Drilling Lab. Hydrogen Ion Index (PH)
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Start the test by doing the pre-test checking using pure water
and check for its value, it is supposed to be a number near
7.03.
2- Prepare a mud of any density, using the previously known
calculations.
3- Put the prepared mud inside a simple container (better to be
glass not steel) .
3- put the sensor head of the device inside the mud, but it is
crucial to make sure that not hit the bottom.
4- Wait until you get a stable reading on the screen of device.
5- record the reading and correct it by doing necessary
calculations with recorded Correction Factor.
6- Measure the final value and present it with mentioning of
room temperature.

8. Drilling Lab. Hydrogen Ion Index (PH)
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1. What is the impact of PH of drilling fluid on the drilling
operations?
>>The value of PH of drilling fluid is concerned to be the main affect
on the solubility of cement almost all of the other drilling fluid
additives, it will cause the washout of the drill strings if it was in acid
side, and also almost all the drilling fluid additives need a certain
specific condition for operating specially Polymers, which they will
totally destroy if the conditions were not proper.
2. Compute the amount of caustic required to raise the pH of
water from 7 to 10.5. the molecular weight of caustic is 40?
Moles of caustic in one liter
N = CM V = 3.161 x 10-4 moles
The amount of caustic required for one liter
m = n x M = 3.161 x 10-4 x 40 = 0.0126 g / liter
3. What is the additive that we will adjust PH with?
>> Sodium Hydroxide which is well known as Caustic
soda, having a chemical formula of NaOH.

9. Drilling Lab. Hydrogen Ion Index (PH)
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4.Explain the term PH with examples in detail?
>>The term "pH" refers to the potential of hydrogen.
The scale measures the logarithmic concentration of
hydrogen ions (H+) and hydroxyl ions (OH-), which
constitute H2O. Because the scale is logarithmic, a
change in pH by a factor of 10 results in a change of one
unit on the pH scale - the pH scale ranges from 0 to 14
and is a measure of the acidity/basicity of water. A
neutral solution, with a pH of 7.0, is achieved when the
activity ofH+ and OH- is balanced. Water that has more
free hydrogen ions (over 7) is acidic and water that has
more free hydroxyl ions (less than 7) is basic or alkaline.
Acids lower the pH of a solution and bases raise the pH
5. .What is the alternative for the lab. PH meter ?
>> The Pocket pH Meter provides a practical
alternative to pH Litmus paper. This easy-to-
use instrument does the work of hundreds of rolls of
indicator paper. With a resolution of 0.1 pH and
accuracy of +0.2 pH, the Pocket pH Meter is just as
reliable as many laboratory models. State-of-the-art
electronics and an easy-to-read digital display make
.
this pH Meter the ideal portable meter

10. Drilling Lab. Hydrogen Ion Index (PH)
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1- PDF Advice viewer (2016)Hydrogen Index
calculations [Online] Available from:
http://pdfadvice.info/how_to_calculate_hydrogen_ion
_concentration [Accessed:April.06th
2016]
2-Fann (2012), PH and its measurements [Online] Available
from: http://www.fann.com/fann/products/industrial-
drilling-products/ph-measurement/idp-ph.page?node-
id=hlz0hxqb.[Accessed: April.06th
2016]
3- Fann (2014) pH Meters - Digital Pocket
[Online] Available from:
http://www.fann.com/fann/products/drilling-fluids-testing/ph-
testing/ph-pocket-meter.page?node-id=hlz0hxqb [Accessed:
April.06th
2016 ] .
4-DOW (2014), Caustic Soda [Online] Available from:
http://www.dow.com/causticsoda/offer/physical.htm
[Accessed: April.06th
2016]
5-Lanny college (2011) How to prepare a buffer solution
[Online] Available from:http://ebooks-
gratuits.me/recherche/How::To::Prepare::A::Buffer::Solut
ion/pdf/8 [Accessed: April.06th
2016]