DEPARTMENT OF PETROLEUM ENGINEERING

PETROLEUM ENGINEERING LABORATORY II

REPORT

BY

AMAO TEMITOPE OLUSEGUN

DEPARTMENT OF PETROLEUM ENGINNERING

MATRIC NUMBER 145374

JULY, 2012.

1

AMAO TEMITOPE OLUSEGUN Department of Petroleum Engineering,

Faculty of Technology, University of Ibadan,

Ibadan. July 25th, 2012.

The Head, Petroleum Engineering Laboratory, University Of Ibadan, Ibadan. Dear Sir,

SUBMISSION OF LABORATORY REPORT

I, AMAO TEMITOPE OLUSEGUN with matriculation number 145374, write to bring to your notice

that I have successfully completed the 2011/2012 session laboratory report.

As required for a successful completion of TPE 416, I hereby tender this submission letter

alongside my laboratory report, which contains comprehensive information as regards knowledge

acquired during the laboratory experiments.

I greatly appreciate your effort.

Yours faithfully,

Amao, Temitope Olusegun.

2

CONTENT

LABORATORY SAFETY---------------------------------------------------------------------------------------------------------- 3

EXPERIMENT 1 DETERMINATION OF SUURFACE TENSION-------------------------------------------------------- 5

EXPERIMENT 2 DETERMIANTION OF DENSITY AND SPECIFIC GRAVITY---------------------------------------- 8

EXPERIMENT 3 FLOW METER RIG EXPERIMENT-------------------------------------------------------------------- 12

EXPERIMENT 4 MEASUREMENT OF LIQUID PERMEABILITY------------------------------------------------------ 17

EXPERIMENT 5 MEASUREMENT OF GAS PERMEABIILITY--------------------------------------------------------- 21

REFRENCES----------------------------------------------------------------------------------------------------------------------- 24

3

LABORATORY SAFETY

Safety in the laboratory requires the same kind of continuing attention and effort that is given to

research and teaching. The use of new and/or different techniques, chemicals, and equipment requires

careful preparation.

Safety in the laboratory must be of vital concern to all those engaged in experimental science work. It is

therefore the responsibility of everyone to adhere strictly to the basic safety precautions provided and

to avoid any acts of carelessness that can endanger his life and that of others around him.

There are five general principles of safety:

1. Practice safety.

2. Be concerned about the safety of others.

3. Understand the hazards associated with your particular experiment.

4. Know what to do in an emergency.

5. Report hazards or hazardous conditions.

1. Practice Safety

• Wear appropriate eye protection at all times.

• Use the hood for hazardous, volatile, and noxious chemicals.

• Smoking is prohibited in the building at all times.

• No food and drinks are allowed during the lab.

• Wear long pants and shoes with no open toes to avoid chemical exposures.

• Become familiar with your experiment before coming to the lab. Read the procedure thoroughly and

study the equipment schematics before attempting to perform any experiment.

2. Be Concerned About the Safety of Others

Your concern for safety must include the people around you. Your experiment must be safely

maintained so that everyone in the area is amply protected and warned of inherent dangers. This

practice of looking out for the other person should include the practice of reminding a friend to wear

safety glasses. Another aspect of this second principle involves alerting those around you of an accident

and to alert personnel in the immediate vicinity of a fire or an emergency. Work as a team. Have

someone in charge of the experiment whose job will be to coordinate what each one is doing. In case of

confusion about any procedure, ask the instructor or the lab assistant.

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3. Understand the Hazards Associated with Your Particular Experiment Prevention is the key to safety. It

is important to know the potential hazards and safety precautions involved in a particular experiment.

Hazards may include toxic substances, electrical circuits, mechanical equipment, and waste chemicals.

Safety precautions should include correct material storage, proper ventilation, proper grounding of

equipment, etc.

It is equally important to always abide by all the instructions for conducting the experimental work

during the laboratory sessions. Below are some guidelines for general laboratory safety and procedures:

1. All students must be familiar with the locations and operational procedures of the Emergency

Shower, Fire Extinguishers, Gas Masks and Fire Blankets.

2. Laboratory coats, safety glasses and safety shoes MUST be worn at all times during the laboratory

session. NO THOABS and open sandals are allowed during the laboratory sessions.

3. Eating, drinking and smoking are strictly PROHIBITED in the laboratory at all times. Laboratory

glassware should NEVER be used for drinking purpose.

4. Report any injury immediately for First Aid treatment, no matter how small.

5. Report any damage to equipment or instrument and broken glassware to the laboratory instructor as

soon as such damage occurs.

5

EXPERIMENT ONE

TITLE: Determination of Surface Tension

AIM: To determine the surface tension of a fluid sample.

Apparatus: Tensiometer, spring, Beaker, Liquid sample.

Special Note on the Use of the Ring Tensiometer

The most common way of measuring the surface and interfacial tensions is with the ring method. The

method is named after a French physicist who developed it in the late 1800's. In this method a platinum

ring with defined geometry is immersed into the liquid and then carefully pulled out through the liquid

surface. The measurement is performed by a Tensiometer, an instrument incorporating a precision

micro balance, platinum-iridium ring with defined geometry and a precision mechanism to vertically

move sample liquid in a glass beaker. The ring hanging from the balance hook is first immersed into the

liquid and then carefully pulled up the surface of the liquid. The force applied on the ring while pulling

through the surface is measured and plotted on a graph. The surface tension is the maximum force

needed to detach the ring from the liquid surface.

Special Note on Handling the Tensiometer

1. The platinum ring is very delicate and should be handled with utmost care.

2. Avoid touching the ring or the papers (used for calibration) with bare hand. Use tweezers for handling

them.

3. When cleaning, clean the ring with the given test fluid and dry it while avoiding deformation of the

ring.

4. Also do not touch the string which gives torsion to the lever arm.

Procedure

A. Preparatory Work

1. using a pair of holding instruments, place the platinum ring into the hook.

2. Set the zero of the Vernier scale and the main scale at the same mark.

3. Release the arrest mechanism.

4. Look onto the reference mark on the mirror and see if the pin hooked to the lever arm and the mark

are at the same level.

5. If they are not at the same level, adjust the lever located at the far end of the string to adjust the

torsion on the string and make the pin and the reference mark at the same level.

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B. Measurement of Surface Tension

1. Arrest the lever arm and place the container with the test fluid on the platform and raise it by turning

the platform adjusting knob. Stop when the ring is just immersed in the liquid.

2. Release the arrest mechanism and turn the knob to apply torsion on the string which eventually will

raise the lever arm up. At the same time lower the platform so that the pin remains on the reference

mark. Record the reading just at the ring breaks free from the liquid.

3. Take three or four readings.

4. Take the average of these readings, which will be used to calculate the surface tension.

5. Repeat the above steps for another sample.

Figure 1: Tensiometer

OBSERVATION

I observed that at the point when the ring was in contact with the surface of the distilled water, there

was no movement or deflection of the Tensiometer. But the moment I rotated the knob on the

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Tensiometer, there was a sudden separation that occurred between the clean ring and the surface of

the distilled water and there was deflection of the reading on the Tensiometer.

RESULT

The surface tension recorded using distilled water as test sample was 43.5dynes/cm.

THEORETICAL BACKGREOUND

Surface tension is a phenomena observed at the surface of a liquid caused by the unbalanced forces

acting on the molecular surface of the liquid in air.

The surface or interfacial tension in the liquid film is the ratio of the surface force to the length

(perpendicular to the force) along which the force acts.

ς=

Surface tension is basically used when characterizing gas-liquid interface. Surface tension is measured in

dynes/cm. Surface tension decreases with an increase in pressure and temperature.

PRECAUTIONS

1. I avoided error due to parallax when taking the Tensiometer reading by ensuring that I had a

vertical view of the Tensiometer scale.

2. I ensured that the ring was dry before the experiment by using tissue paper to dry off the

previous test sample from the ring.

CONCLUSION

The surface tension is an important property in reservoir engineering calculations and designing

enhanced oil recovery projects.

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EXPERIMENT TWO

Title: Determination of density and specific gravity

Aim: to determine the density and specific gravity of fluid samples at different temperatures.

Apparatus: Pycnometer (density bottle), water bath, thermometer, acetone, water, crude oil, beakers,

electric weighing balance.

Procedure (for crude oil as test sample)

1. I rinsed the Pycnometer bottle with acetone which is a volatile substance so as to ensure that

the density bottle is dry.

2. I weighed the Pycnometer when it was dry and empty so as to determine its weight.

3. I filled the Pycnometer (density bottle) with the given crude oil sample and inserted the stopper

thereby making sure that the hole in the stopper is filled.

4. I hung the density bottle (Pycnometer) in the water bath at the given temperature and allowed

5 minutes to attain equilibrium.

5. I removed the Pycnometer from the water bath and wiped dry.

6. I weighed the Pycnometer plus sample on the weighing balance and took the reading.

7. I repeated the procedure at different temperatures. The result is presented in the table below.

Pycnometer Water bath

Figure 2

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Result

T/oC Wp/g Wop/g Vo/cc Ρo/(g/cc)

44.5 19.91 66.33 50.0 0.9284

56.5 19.91 66.10 50.0 0.9238

67.0 19.91 65.63 50.0 0.9144

77.0 19.91 65.63 50.0 0.9108

84.5 19.91 65.06 50.0 0.9030

T=Temperature (oC)

Wp=Weight of dry Pycnometer (g)

Wop= Weight of Pycnometer filled with oil (g)

Wo= Weight of oil (g)

Vo= Volume of density bottle (Pycnometer) (cm3) = 50ml= 50cc

Procedure for water as test sample

1. I rinsed the Pycnometer bottle with acetone which is a volatile compound so as to ensure that

the density bottle is dry.

2. I weighed the empty and dry Pycnometer to determine its weight.

3. I filled the Pycnometer with water and inserted the stopper thereby making sure that the hole in

the stopper is filled.

4. I hung the density bottle in the water bath at the given temperature and allowed 5 minutes for

equilibrium.

5. I removed the Pycnometer from the water bath and wiped dry, I thereafter weighed it.

RESULT

T/oC Wp/g Wwp/g Ww/g Vo/cc Ρw/(g/cc)

38.0 20.49 71.2 50.71 50.0 1.0142

49.0 20.49 71.0 50.51 50.0 1.0102

59.5 20.49 70.8 50.31 50.0 1.0062

66.0 20.49 70.6 50.11 50.0 1.0022

77.0 20.49 70.5 50.01 50.0 1.0002

T=Temperature (oC)

Wp=Weight of dry Pycnometer (g)

Wwp= Weight of Pycnometer filled with water (g)

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Ww= Weight of water (g)

Vw= Volume of density bottle (Pycnometer) (cm3) containing water = 50ml= 50cc

Table of Specific gravity and API gravity

T/oC Wp/g Wop/g Wo/g Ρo (g/cc) Ρw/(g/cc) SG API

44.5 19.91 66.33 46.42 0.9284 1.0062 0.9227 21.85

56.5 19.91 66.10 46.19 0.9238 1.0062 0.9181 22.62

67.0 19.91 65.63 45.72 0.9144 1.0062 0.9088 24.20

77.0 19.91 65.45 45.54 0.9108 1.0062 0.9051 24.84

84.5 19.91 66.06 45.15 0.9030 1.0062 0.8974 26.18

SG= Specific Gravity=

=

API Gravity= APIo=

OBSERVATION

1. I observed that the crude oil flowed out of the density bottle stopper as the density bottle was

heated in the water bath.

2. From the result, I observed that there was a decrease in density and specific gravity as

temperature increased.

3. I observed that the variation of density of the water with respect to temperature was minute

(very small).

THEORETICAL BACKGROUND

Density (ρ) is defined as the mass of the fluid per unit volume. In general, it varies with pressure and

temperature. The dimension of density is kg/m3 in SI or lb/ft3 in the English system.

Specific gravity (γ) is defined as the ratio of the weight of a volume of liquid to the weight of an equal

volume of water at the same temperature. The specific gravity of liquid in the oil industry is often

measured by some form of hydrometer that has its special scale. The American Petroleum Institute (API)

has adopted a hydrometer for oil lighter than water for which the scale, referred to as the API scale, is

API Gravity= APIo=

When reporting the density the units of mass and volume used at the measured temperature must be

explicitly stated, e.g. grams per millilitre (cm3) at T (OC). The standard reference temperature for

international trade in petroleum and its products is 15 OC (60 OF), but other reference temperatures may

be used for other special purposes.

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The Pycnometer is an accurately made flask, which can be filled with a known volume of liquid. The

specific gravity of liquid is defined as the ratio of the weight of a volume of the liquid to the weight of an

equal volume of water at the same temperature.

Both weights should be corrected for buoyancy (due to air) if a high degree of accuracy is required. The

ratio of the differences between the weights of the flask filled with liquid and empty weight, to the

weight of the flask filled with distilled water and empty weight, is the specific gravity of the unknown

fluid. The water and the liquid must both be at the same temperature.

PRECAUTION

1. When the stopper was inserted, I ensured that it was filled with the sample fluid.

2. I ensured that the Pycnometer did not come in contact with the base of the water bath.

3. I ensured that the thermometer did not ouch the base of the water bath.

4. I avoided error due to parallax when taking the reading from the thermometer.

CONCLUSION

The experiment is useful in obtaining the densities and specific gravities of the crude oil at different

temperatures since the density and specific gravity are temperature dependent.

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EXPERIMENT THREE

Title: Flow Experiment

Aim: To determine the head losses of different flow measuring devices.

Objective: To compare and contrast the head losses in the orifice plate (orifice meter) and venture

meter when a liquid flows through them.

Apparatus: The flow rig consisting of: a centrifugal pump that circulates water through the system, a

water reservoir for water storage, a manometer which measures the differential pressure between the

entry and exit of each measuring device, a water level indicator which indicates the volume of water

that has accumulated in a drainable volumetric tank, flow measuring devices (orifice plate and venture

tube). Other apparatus are stop watch and the water used as the flowing liquid.

Procedure for the orifice plate

1. I filled the tank with the water to the brim.

2. I connected the rubber hose from the orifice to the big manometer appropriately.

3. I regulated the water level in the arms (P1 and P2) of the big manometer to equal level.

4. I regulated the water level in the two arms (P1 and P2) of the big manometer to equal level.

5. I turned the water pump valve to zero point.

6. I connected the equipment to power supply and switched the flow-rig power on.

7. I started the stop watch when the water level in the small manometer is stabilized.

8. I stopped the watch when the water has moved from 0.5 as indicated on the small manometer.

9. I took the reading off the big manometer and recorded the time taken.

10. I subtracted P2 from P1

11. Subsequent readings were obtained by increasing the flow rate from the pump and following

the procedure outlined above.

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Figure 3: Flow Rig

THEORETICAL BACKGROUND

This experiment was aimed at measuring the head loss between the inlet and the outlet points of a

measuring device. This is done by determining the coefficient of discharge of the flow through each

device.

The principle is based on the theory that energy is lost when a flowing fluid velocity is reduced by

constricting its path of flow. The energy losses are measured in terms of the head loss experienced by

the fluid.

In a flow metering device based on the Bernoulli’s equation, the downstream pressure after an

obstruction will be lower than the upstream pressure before. To understand orifice, nozzle, and venture

meters, it is necessary to therefore explore the Bernoulli’s equation.

Assuming a horizontal flow (neglecting minor elevation differences between measuring points), the

Bernoulli’s equation can be modified to:

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2 2

2 11 1 2 2

2 2

v vpV p V

g g

………………… (1)

Where

P= pressure

v= flow velocity

V= specific volume

The equation can be adapted to vertical flow by adding elevation heights h₁ and h₂.

Assuming uniform velocity profiles in the upstream and downstream flow, the continuity equation can

be expressed as

q= V₁A₁= V₂A₂………………..(2)

Where

q= flow rate

A= flow area

Eq. 1 may be simplified by assuming that V₁ = V₂ = V, an assumption that is approximately true and is

later corrected by a term called the expansion factor. Then,

v₁² - v₂² = 2gV (p₂ - p₁) = 2gh

The term h is the differential head loss between points 1 and 2 expressed as “feet of fluid” (the fluid

flowing in the system). The velocities may be expressed in terms of volume flow rate gq and diameters

d₂ and d₁ (internal diameter of pipe and orifice opening respectively). This substitution yields an

intermediate equation.

Combining equations (1) and (2) gives

2

4

2

1

A ghq

……….. (3)

Where

2A = area of orifice plate opening

d₂ = orifice, venture, or nozzle inside diameter

d₁ = upstream and downstream pipe diameter

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= d₂/d₁ diameter ratio

The theoretical flow rate q will in practice be smaller (2-40%) due to geometrical conditions.

The ideal equation (3) can be modified with a discharge co-efficient, dC

2

4

2

1d

A ghq C

Figure 4: Flow through Orifice Plate

ORIFCE PLATE

Volume(cc) P1(mmH2O) P2(mmH2O) P1-P2(mmH2O) Time (s) Q=

(cc/s) H=

5000 460 430 30 244.0 20.49 3.06

5000 440 320 120 173.0 28.90 12.23

5000 428 322 106 170.0 29.41 10.81

5000 685 320 365 62.0 80.65 37.21

5000 415 327 88 148.0 33.78 8.97

5000 434 330 104 144.0 34.72 10.60

5000 418 330 88 146.0 34.25 8.97

H=

=

Ρ=Density of water=(g/cc)

g=acceleration due to gravity

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OBSERVATION

1. I observed that the higher the pressure difference between the inlet and the outlet of the orifice

plate, the lower the time required for the 5000cc to flow and subsequently, the lower the flow

rate.

PRECAUTIONS

1. The level of water in the reservoir was checked at intervals to ascertain it was above the critical

level.

2. I ensured that the two manometer readings were at the same level before flow began.

3. I ensured that the stop watch was started at the instant flow began and stooped it when flow

ended.

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EXPERIMENT FOUR

Title: Measurement of Liquid Permeability

Aim: To determine the liquid permeability of a core sample.

Apparatus: Core holder, Calibrated cylinder, stop watch, flow pump.

Figure 5: Core holder and Liquid Permeameter

PROCEDURE

1. I loaded the 100% saturated core plug into the core holder and applied appropriate overburden

pressure of 0.25psi.

2. I flowed several volumes of distilled water through the sample so a s to ensure a steady

laminar flow.

3. I started the stop watch and measured 5cm3(5ml) of liquid water into a calibrated test tube at

the point of first drop.

4. When the 5ml calibrated cylinder was full, I stopped the stop watch and noted the reading.

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Figure 6: Liquid Permeameter

THEORETICAL BACKGROUND

Permeability is a measure of the ease with which a formation permits a fluid to flow through it.

Permeability is a property of the porous medium and is a measure of the capacity of the medium to

transmit fluids. Permeability is an INTENSIVE property of a porous medium (e.g. reservoir rock). To be

permeable, a formation must have interconnected porosity (intergranular or intercrystalline porosity,

interconnected vugs, or fractures).

Permeability is measured in Darcy units or more commonly millidarcy (md - one thousandth of a Darcy)

after Henry Darcy who carried out some pioneering work on water flow through unconsolidated

sandstones. It is defined by the equation which expresses Darcy's law. Generally stated as:

K=

Q= the total discharge of fluid per unit time (cm3/s)

A= the cross-sectional area of the flow path (cm2)

L= the length of the flow path (cm)

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µ= Dynamic fluid Viscosity (centi poise)

K= the permeability in Darcy

P1 – P2 = Pressure difference (atm)

To determine the permeability of a formation, several factors must be known: the size and shape of the

formation, its fluid properties, and the pressure exerted on the fluids, and the amount of fluid flow. The

more pressure exerted on a fluid, the higher the flow rate. The more viscous the fluid, the more difficult

it is to push through the rock. Viscosity refers to a fluid’s internal resistance to flow, or its internal

friction. For example, it is much more difficult to push honey through a rock than it is to push air through

it. Permeability is measured in Darcy. Few rocks have a permeability of 1 Darcy, therefore permeability is

usually expressed in millidarcies or 1/1000 of a Darcy.

RESULT

Length (L) of core sample= 5.71cm

Diameter= 3.785cm

Radius=

Area of cross section= πr2= 3.142 x 1.89252= 11.246cm2

Viscosity= 0.89cp

The observed time (T) = 1.8 minutes

K=

= Differential Pressure= 0.25psi

K=

K=

k=1209.5mD

Flow rate=

=

= 0.0463cc/s

PRECAUTIONS

1. I avoided error due to parallax when reading the time from the stop watch.

2. I ensured the stop watch was stopped the instant 5ml liquid volume was filled.

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3. I pre saturated the core for 24 hours.

CONCLUSION

The calculated permeability of 1209.5mD indicates that the sample has an excellent permeability. This is

consequent upon the fact that there is a high degree of interconnectivity between the pore spaces.

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EXPERIMENT FIVE

Title: Measurement of Gas permeability in a porous medium

Aim: To determine the permeability of a porous media using nitrogen gas.

Apparatus: core holder, end stem, rubber boot, core plug, stop watch, bubble tube flow meter, pressure

gauge.

Figure 7: Gas Permeameter

THEORETICAL BACKGROUND

Permeability is a property of the porous medium that measures the capacity and ability of the formation

to transmit fluids. The rock permeability, k, is a very important rock property because it controls the

directional movement and the flow rate of the reservoir fluids in the formation.

This rock characterization was first defined mathematically by Henry Darcy in 1856. In fact, the equation

that defines permeability in terms of measurable quantities is called Darcy’s Law. Darcy developed a

fluid flow equation that has since become one of the standard mathematical tools of the petroleum

engineer. If a horizontal linear flow of an incompressible fluid is established through a core sample of

length L and a cross-section of area A, then the governing fluid flow equation is defined as;

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V=-

Where v = apparent fluid flowing velocity, cm/sec

k = proportionality constant, or permeability, Darcys

µ = viscosity of the flowing fluid, cp

dP/dL = pressure drop per unit length, atm/cm

Standard laboratory analysis procedures will generally provide reliable data on permeability of core

samples. If the rock is not homogeneous, the whole core analysis technique will probably yield more

accurate results than the analysis of core plugs (small pieces cut from the core). Procedures that have

been used for improving the accuracy of the permeability determination include cutting the core with an

oil-base mud, employing a pressure-core barrel, and conducting the permeability tests with reservoir oil.

Permeability is reduced by overburden pressure, and this factor should be considered in estimating

permeability of the reservoir rock in deep wells because permeability is an isotropic property of porous

rock in some defined regions of the system, that is, it is directional. Routine core analysis is generally

concerned with plug samples drilled parallel to bedding planes and, hence, parallel to direction of flow

in the reservoir.

PROCEDURE

1. I determined the length, diameter and cross sectional area of the plug sample.

2. I inserted the plug into the rubber boot and attached to end stems to either side.

3. I loaded everything into the core holder and screwed down the core holder (from the gas

regulator). I connected the down stem line from the core holder to the Permeameter.

4. I opened the gas cylinder using the gas regulator and injected gas into the sample and watched

as the gas lifted a single bubble in the bubble tube (burette).

5. I adjusted the pressure regulator to ensure laminar flow.

6. Using the stop watch, I timed the bubble time of travel over 25cc to determine the flow rate.

7. I disconnected the entire setup and calculated permeability using Darcy’s law.

RESULT

Length L= 5.731cm

Diameter D= 3.785cm

Radius=

Area of cross section= πr2= 3.142 x 1.89252= 11.246cm2

Viscosity µ= 0.177cp

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Observed time= 50.50 Seconds

P1= 1.5psi

P2=0 psi

Flow rate=

=

= 0.495cc/s

Flow rate= Q= 0.495cc/s

K=

K=

K= 0.0298 Darcy

K= 29.18mD

PRECAUTIONS

1. I ensured that the flow rate was less that 1cc/second all through the experiment for Darcy’s law

to hold.

2. The rubber tube joining the permeameter to the pressure cylinder was properly fitted to

prevent gas leakage.

CONCLUSION

The calculated permeability for gas (29.78mD) indicates that the core sample is fairly permeable. As a

result, it can be inferred that the interconnectivity between the pore spaces is low. The permeability is

low as a result of the tightness and consolidation of the sample used.

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REFRENCES

1. Amyx J.W., Bass Jr. D.M. and Whiting R.L.: “Petroleum Reservoir Engineering”, McGraw-Hill,

1960.

2. Bear J.C.: “Dynamic of Fluids in Porous Media”, American Elsevier, 1972.

3. Koederitz L.F., Harvey A.H. and Honarpour M.: “Introduction to Petroleum Reservoir Analysis;

Laboratory Workbook”, Gulf Pub. Co., 1989.

4. EZ Tensiometer (Model 101) Instruction Manual, Temco Inc, Tulsa, OK, USA.