MODULE 1

DETERMINATION OF GAS SPESIFIC GRAVITY AND OIL SPESIFIC GRAVITY

PRACTICUM REPORT

Name : Muhamad Choirul Azis

NIM

Group

:

:

12213060

2nd Shift Group 2

Practicum Date : Oktober, 7th 2014

Due Date : October, 14th 2014

Lecturer : Zuher Syihab ST, Ph.D.

Module Assistant : Alris Alfharisi (12211014)

Achmad Zulfikar K (12211082)

LABORATORY OF RESERVOIR FLUID ANALYSIS

MAJOR OF PETROLEUM ENGINEERING

BANDUNG INSTITUTE OF TECHNOLOGY

2014

CONTENTS

CONTENTS........................................................................................................... i

LIST OF TABLES................................................................................................. ii

BAB I PURPOSE OF EXPERIMENT

1.1 Purpose of experiment............................................................. 1

BAB II PRINCIPLE OF EXPERIMENT

2.1 Principle of experiment ........................................................... 1

BAB III DATA PROCESSING

3.1 Experimental Data.................................................................... 33.2 Data Processing........................................................................ 4

BAB IV ANALYSIS

4.1 Assumption ............................................................................. 64.2 Practicum Sustainability.......................................................... 64.3 Tool.......................................................................................... 64.4 Result Analysis........................................................................ 7

BAB V CONCLUSION AND RECOMENDATION

5.1 Conclusion................................................................................ 85.2 Recomendation.......................................................................... 8

BAB VI IMPRESSION AND SUGGESTION

6.1 Impression................................................................................ 96.2 Suggestion.................................................................................... 9

BAB VII REFERENCES

7.1 Bibliography............................................................................. 10

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LIST OF TABLES

Table 1 Experiment data 0API with hydrometer....................................... 3

Table 2 Experiment data with picnometer................................................ 3

Table 3 Experiment data with effusiometer.......................................... 3

Table 4 Data Processing for Picnometer............................................... 4

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DETERMINATION OF GAS AND OIL SPESIFIC GRAVITY

I. PURPOSE OF EXPERIMENT

1. Understand the determination of the physical properties of gases, namely SG, density, viscosity, and gas compressibility factor.

2. Determining gas SG using effusion. 3. Determining the physical properties of the fluid gas4. Determine specific gravity of crude oil 5. Knowing the effect of temperature towards specific gravity of crude oil

II. PRINCIPLE OF EXPERIMENT

Specific Gravity (SG) is one of the most important parameters in petroleum

industry . SG is a general property of a fluid that states heaviness of fluid itu. In

petroleum industry, specifically SG certify the quality of the fluid. The purpose

of the quality here is a measure of how heavy hydrocarbons per unit volume. A

hydrocarbon has good quality if SG is low, which means it will have a heavy

hydrocarbon that is small per unit volume is so much easier to flow in the

reservoir.

As has been revealed in the explanation, the principle of this experiment is the

law of effusion / diffusion which is a function of flow time on efusiometer tool.

Diffusion is basically a process of equalization of physical state spontaneously.

When it comes to two different substances, then the diffusion is mixing the

particles of the substance evenly. While effusion is the process of diffusion

through narrow gaps or pores.

There are two laws that underlie this experiment. The first is the law of Graham

(1830) which basically states that the ratio of the rate of effusion / diffusion of

two gases ternalik versus the square root of its density at the same temperature

and pressures. Mathematically it can be written as follows

?1?2 = ? ? 2? ? 1

where, v = rate of diffusion / effusion

d = density of gas

(subscript 1 and 2 show of the different gases)

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While the second is the Avogadro's Law states that the conditions of pressure,

temperature and specific volume, the density of the gas is directly proportional

to the number of molecules. Mathematically it can be written as follows

? 1? 2 = ? 1? 2where, M = number of gas molecules

With reference to the understanding of diffusion and effusion, then for the same

mileage Graham Law and Avogadro's law can be combined into:

?12?22 = ?22?12 = ? 2? 1 = ? 2? 1If d2 is the density of the gas which we will specify its SG and d1 is the density

of the air is dry, then the ratio between d2 and d1 is an SG value of the gas

whose value is proportional to the square of the ratio of flowrate at the same

distance and measured at a temperature and pressure same.

In this experiment we use a tool efusiometer, so SG obtained from the above

calculation must be corrected for the vapor pressure of dry (W), chamber

pressure (P), and the average pressure (p) is defined as follows

?? ∗ = ??2?1?2 + 0.627 ?? + ? − ? ???2?1?2 − 1?

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III. DATA PROCESSING

Experimental DataTable 1 Experiment data 0API with hydrometer

Suhu (0F) 0API

78 38.5

78 38.5

78 38.5

Table 2 Experiment data with picnometer

No Sampel Massa picnometer

Massa picnometer + Volume

kosong (gr) sampel (gr) picnometer (ml)

1 Minyak (T=320C) 11,67 16.55 511,66 16.55 511,66 - 5

2 Minyak (T=290C) 11,67 16.56 511,66 16.56 511,66 16.55 5

Table 3 Experiment data with effusiometer

Sample Experiment Time (s)

N2 I 44.37

II 44.11

III 43.88

CO2 I 37.93

II 37.20

III 37.18

Dry Gas I 45.28

II 45.25

III 45.91

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Data Processing

a) Measurement spesific gravity of crude oil using hydrometer

Sampel air

˚? ? ? = ?ata-rata = 38.5

˚? ? ? = 141,5? ? − 131,5 = 38.5

Maka, SG = 0,832352

b) Measurement spesific gravity of crude oil using picnometer

Table 4 Data Processing for Picnometer

*

with assumption density of water at the same pressure and temperature is 1

g/cm3

#T= 32 0C

SG= ρ oilρ w ater =

0.97711 = 0.99774

#T= 29 0C

SG= ρ oilρ w ater =

0.97941 = 0.9794

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T(0C) Sample Average mass (gr) Sample mass(gr)

Density(g/cm3)picnometer

kosongPicnometer+sampel

32 Crude oil 11.663 16.55 4.887 0.977429 Crude oil 11.663 16.56 4.897 0.9794

Average time :

tN2 = 44.12 s

tCO2 = 36.10 s

tdry = 45.48 s

Assume :

Pdry (W) = 0.0298 mmHg

Proom (P) = 760 mmHg

Pavg (p) = 12 mmHg

SGNitrogen = ? ? 2 ^2

? ? ?? ^2 = 1946.572068.43 = 0.941 ;SGCO2 =

? ? ? 2 ^2? ? ?? ^2 = 1303.45

2068.43 = 0.630

After correction :

SGN2 = 0.885 ; SGCO2 = 0.62999

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IV. ANALYSIS

Assumption

Asumsi yang digunakan dalam praktikum ini adalah

1. The inert gas used, meaning that no reaction occurs between

the water or the dry gas with a facilitator.

2. The experiments were conducted in laboratory conditions of

temperature and pressures are constant.

3. The process of bleach-off was done perfectly without leaving

the previously used gas in pipelines or equipment.

4. There is no leakage in the pipe Effusiometer tools and

pipelines.

5. The distance traveled during the effusion of gas in the same

tube.

6. All equipment used to function properly.

7. When measuring the density with picnometer, oil filled

Practicum Sustainability

Practicum this time goes well and there are no barriers.

Tools

1. Hidrometer

Principle

Using Archimedes law that objects immersed in a fluid will get upward thrust equal to the weight of the displaced fluid.

How it work

Hydrometer is immersed into the fluid would have thrust is proportional to the displaced fluid and stable when it manandakan that upward thrust equal to the weight of the hydrometer submerged. And hydrometer convert thrust into units of density (0API) .

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2. Effusiometer

Principle

Flowrate of fluid on a narrow slit in effusiometer characterize the physical properties of gases.

How it work

Air flow through a narrow slit into effusiometer assuming air flow per particle then air flow is stopped and there was a diffusion-effusion .Waktu characterize the physical properties of the gas flow

Result Alanysis

The essence of the experiment is to find the value times the SG of oil by

using Hydrometer and Picnometer. Both tool can be used, but the

selection of the tool depends on the accuracy that we want .Hydrometer

measurement is much faster than the picnometer because the results

obtained are a direct readout 0API. However if we use picnometer we do

not directly get the value of the SG, but it is necessary to process the

mass distribution of the volume.

Measurements with a hydrometer hydrometer basically just dunked on a

sample of crude oil in the measuring cup. If the API does not reach the

scale of the sample, then replace the appropriate hydrometer. then

dividing by the volume of the sample container.

On experiment using picnometer the results showed that increasing the

temperature of the lower density of crude oil because the volume of crude

oil is expand.

On experiment using effusiometer, semakin ringan gas maka semakin

cepat laju gas dan densitasnya semakin mirip dengan udara sehingga

spesific gravitynya makin besar.

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V. CONCLUSION AND RECOMENDATION

Conclusion :

With hydrometer,crude oil has spesific gravity = 0,832352

With Picnometer at T=29 0C, crude oil has spesific gravity = 0.9794 With Picnometer at T=32 0C, crude oil has spesific gravity = 0.99774 With Effusiometer, N2 gas has spesific gravity = 0.885

With Effusiometer, CO2 gas has spesific gravity = 0.62999

Recomendation :

In this experiment all the tools and materials are available and can be used

properly so strongly support the sustainability of the practicum. Keep it!

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VI. IMPRESSION AND SUGGESTION

Impression :

This is the easiest one practicum of all that I have taken and the assistants are

also very relaxed so I do not worry.

Suggestion:

Keep your goodness assistant!!

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VII. REFERENCES

McCain, William D.Jr., The Properties of Petroleum Fluids, 2nd Edition, PennWell Publishing Co., 1990, Tulsa, Oklahoma.

W.R. Siagian, Utjok. Diktat Kuliah Fluida Reservoir. Departemen Teknik Pertambangan dan Perminyakan. 2002. Institut Teknologi Bandung, Bandung.

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