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Boon Ee Juan Report of Visit to Petronas Research Sdn Bhd For Geochemistry Subject, QAB2013 Prepared by, Name: BOON EE JUAN Student ID: 12542 Program: Petroleum Geoscience This report is intended to review the use of materials, apparatus, and analysis machines to do analyses on the source rock sample. To carry out the analyses until the final conclusion is made, they involve the preparations of rock samples, the methodologies to conduct the lab, and the interpretation of analyses results. In this report, every lab works will be discussed part by part, from preparation of sample to the expected result and interpretation. Soxhlet Extraction The objective of this lab is to extract the bitumen from the source rock. Material: Source rock sample, copper granule, Ageothropic solvent (93% Dichloromethane, 7% Methanol), and anti-bumping granules Apparatus: Soxhlet extractor, grinder, 180 micron size sieve, cellulose thimble, and rotary evaporator Methodology: 1. The source rock sample is crushed into powder form using grinder. 2. The powder is sieved using 180 micron size sieve. 3. This powder is placed inside the cellulose thimble and loaded into the main chamber of the Soxhlet extractor. 4. Soxhlet extractor comprises of 3 main parts: the flask; the Soxhlet main chamber with distillation arm, cellulose thimble and siphon; the condenser. 5. The flask is filled with Ageothropic solvent with volume 3 to 4 times the volume of the Soxhlet chamber, copper granule, and anti-bumping granules.
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Report of Visit to Petronas Research Sdn Bhd

Oct 07, 2014

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Page 1: Report of Visit to Petronas Research Sdn Bhd

Boon Ee Juan

Report of Visit to Petronas Research Sdn Bhd

For Geochemistry Subject, QAB2013

Prepared by,

Name: BOON EE JUAN

Student ID: 12542

Program: Petroleum Geoscience

This report is intended to review the use of materials, apparatus, and analysis machines to do analyses

on the source rock sample. To carry out the analyses until the final conclusion is made, they involve the

preparations of rock samples, the methodologies to conduct the lab, and the interpretation of analyses

results. In this report, every lab works will be discussed part by part, from preparation of sample to the

expected result and interpretation.

Soxhlet Extraction

The objective of this lab is to extract the bitumen from the source rock.

Material: Source rock sample, copper granule, Ageothropic solvent (93%

Dichloromethane, 7% Methanol), and anti-bumping granules

Apparatus: Soxhlet extractor, grinder, 180 micron size sieve, cellulose thimble,

and rotary evaporator

Methodology:

1. The source rock sample is crushed into powder form using grinder.

2. The powder is sieved using 180 micron size sieve.

3. This powder is placed inside the cellulose thimble and loaded into the

main chamber of the Soxhlet extractor.

4. Soxhlet extractor comprises of 3 main parts: the flask; the Soxhlet main

chamber with distillation arm, cellulose thimble and siphon; the

condenser.

5. The flask is filled with Ageothropic solvent with volume 3 to 4 times the

volume of the Soxhlet chamber, copper granule, and anti-bumping

granules.

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6. The flask with its solvent is heated to reflux. The copper granule is used to absorb sulphur while

the anti-bumping granules are used to maintain the boiling of solvent at 100oC.

7. The solvent vapour travels up the distillation arm and condensed by the cooling circulating

water. After that, the warm solvent will drip into the cellulose thimble housing the powder. The

bitumen will then dissolve into the warm solvent, leaving non soluble content in the thimble.

When the Soxhlet chamber is almost full, the solvent is emptied by flowing through the siphon

side arm back into the flask.

8. This cycle will be repeated for 3 days to extract the bitumen from the powdered sample.

9. Rotary evaporator is used to remove the solvent from the final mixture in the flask, yielding the

extracted bitumen.

10. The extracted bitumen will be further chromatography into aliphatic and aromatic compound.

Liquid Column Chromatography (LCC)

The objective of this lab is to separate NSO and extract aliphatic and aromatic compound from the

bitumen.

Material: Bitumen extraction, alumina, silica gel, glass wool, petroleum spirit, and dichloromethane

Apparatus: Burette, tripod clamp, and beakers

Methodology:

1. A burette is clamped on the tripod.

2. The pit of the burette is stopped with a piece of glass wool and a beaker is placed

below the pit.

3. Silica gel is poured into the burette and followed by a layer of alumina. Silica gel

and alumina function as an adsorbent or stationary phase.

4. The bitumen extraction is added on top of the alumina layer together with the

petroleum spirit. It is the mobile phase. The petroleum spirit act as the solvent or

eluent of aliphatic that will bring the aliphatic to flow through the stationary

phase and drip out from the burette to the beaker. The function of alumina is to

absorb the NSO or nitrogen, sulphur and oxygen elements.

5. The aliphatic beaker is removed after no more dripping of aliphatic. A new empty

beaker is placed below the pit.

6. Dichloromethane is added into the bitumen extract as the solvent or eluent of

aromatic that will bring the aromatic to flow through the stationary phase and

drip out from the burette to the beaker.

7. The extracted liquid aromatic and aliphatic compounds are now prepared to be further analyse

using GCMS. The GCMS will further separate the aliphatic and aromatic compound into

fractions of methane, ethane, propane, etc.

Figure 1: LCC

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The process of mobilising the aliphatic and aromatic compounds through the stationary phase is

depending on their polarity. Let’s say we want to mobilise the aliphatic compound through the

stationary phase, we have to choose petroleum spirit as an eluent that has the approximately same

polarity with the aliphatic compound. Since the aromatic compound has higher polarity compared to

the aliphatic compound, it will not be mobilised as fast as aliphatic compound. The concept is we

mobilise the lesser polarity compound first, then the higher polarity compound using higher polarity

eluent solvent.

LCC is a good separator of aliphatic and aromatic compounds but it takes longer time to separate them

compared to Thin Layer Chromatography (TLC).

Thin Layer Chromatography (TLC)

The objective of this lab is to extract aliphatic and aromatic compound from the bitumen but the

amount extracted will be lesser compared to the amount extracted using LCC. TLC is the second way of

extracting aliphatic and aromatic compound with shorter time but the sample is prone to

contamination because of the adsorbent characteristic of alumina that absorb moisture.

Material: Bitumen extraction, alumina, calcium sulphate (gypsum), water, petroleum spirit, filter paper,

and dichloromethane

Apparatus: Glass plate, oven, transparent container, flasks and syringe

Methodology:

1. The alumina is mixed with calcium sulphate and water. It acts as the stationary phase.

2. The adsorbent mixture is then spread on a glass plate and flattens to thickness of around 0.5 –

2.0 mm.

3. The adsorbent coated glass plate or TLC plate is dried and heated in the oven for 30 minutes at

110oC. After that, it is cooled down in room temperature.

4. A syringe is used to inject a row of spots of bitumen extract at about 1.5cm from the bottom

edge of the TLC plate.

5. A small amount of petroleum spirit is poured into the transparent container with less than 1cm

height. It acts as the eluent or mobile phase.

6. A strip of filter paper is put into the container with its lower end immersed into the petroleum

spirit and the filter paper lies on the container wall. The upper end of the filter paper reached

almost to the top of the container.

7. The container is closed with a lid and left for few minutes to let the petroleum spirit vaporize

the filter paper and saturate the air in the container.

8. The TLC plate is then placed in the container with the row of bitumen spots not touching the

petroleum spirit. The container is covered with a lid.

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9. The petroleum spirit which is the eluent will move up the TLC plate by capillary action. When

the petroleum spirit meet the row of bitumen spots, it will carry along the less polarised

aliphatic up the TLC plate. The more polarised aromatic compound will be in stationary phase

but they would move very slowly upward. Thus, there is a separation of less polarised aliphatic

band on the top and more polarised aromatic at the lower TLC plate.

10. Under the UV light, the band of aliphatic and aromatic compound can be seen.

11. The aliphatic band is scrapped into a flask and mixed with petroleum spirit.

12. The aliphatic compound is then extracted from the mixture.

13. The aromatic band is scrapped into a flask and mixed with dichloromethane.

14. The aromatic compound is then extracted from the mixture.

Gas Chromatography – Mass Spectrometer (GCMS)

The objective of this lab is to separate the aliphatic and aromatic compound into fractions of methane,

ethane, propane, etc using gas chromatography. Then, their existence will be further confirmed by the

mass spectrometer.

Material: Extracted liquid aliphatic and aromatic compound

Apparatus: Syringe, and Gas Chromatography – Mass Spectrometer

GCMS consists of 2 components. They are gas chromatograph and mass spectrometer. The extracted

liquid aliphatic and aromatic compound will first enter the gas chromatograph for fractioning and then

the component compounds of them will enter the mass spectrometer to be ionized and confirmed.

Methodology of Gas Chromatography (GC):

1. The extracted liquid aliphatic compound is injected into the entrance of

the capillary column by using a syringe. (Note: The liquid compound must

be volatile so that it can be vaporized in the capillary column.)

2. The liquid aliphatic will be vaporized by the oven. Since different

components like methane, ethane, and propane in the aliphatic

compound has different boiling point, they will be vaporized at their

respective boiling temperature.

3. An unreactive gas such as nitrogen or an inert gas such as helium is used

Figure 2: The separation of aliphatic and aromatic compound.

Figure 3: Capillary column inside the GC

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as mobile phase to transport the vaporized component compounds through the capillary

column.

4. The wall of the capillary column is coated with different stationary phase.

5. When the vaporized component compounds or gas stream flow through the capillary column,

they will interact with the stationary phase on the wall of the column. Different component

compounds interact differently with different stationary phase based on the strength of

absorption and in this process, they are separated. Thus, various component compounds will

elute at a different time and this is known as the retention time that can be qualitatively used

to recognise the component compounds.

6. The exit of the gas stream is monitored by a detector where the retention time and the

quantity of the component compounds can be determined. The most commonly used detector

is the flame ionization detector (FID) and the thermal conductivity detector (TCD).

7. GC can provide a result call gas chromatogram. The Y-axis shows the intensity whereas the X-

axis shows the retention time of the component compounds. Each peaks show different

component compounds eluting at different time with different intensity.

8. The processes are repeated again for extracted liquid aromatic compound.

Methodology of Mass Spectrometer (MS):

1. Straight after the ejection of component compounds from GC, they are re-injected into the vacuum chamber of MS where they are impacted with electron beam.

2. The electron beam ionized the component compounds and breaking them into ionized molecule fragments with mass to charge ratio m/z. This m/z is the characteristic of the molecule fragments. If the charge is fixed, then the m/z could be represented by the mass.

3. The quadrupole mass spectrometer is the detector of the m/z. It functions using 2 pairs of electrically charged poles that will drive and focus the ionized molecular fragments into the detector.

4. Since the charge of the ionized molecule fragments are fixed, the mass of them would affect the different in their acceleration and momentum when driven by the quadrapoles’ electric field. Thus, their mass spectra could be obtained.

Figure 4: Gas chromatogram

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5. MS can provide a result call mass spectra. The Y-axis shows the intensity whereas the X-axis shows the m/z ratio. Each peaks show different molecular fragments with different mass. A series of spectrum would be obtained for each separated component compounds in the aromatic and aliphatic after the GC.

Vitrinite Reflectance

The objective of this lab is to use the Vitrinite Reflectance (Vro) to measure the thermal maturity of source rock. The source rock can be an organic rich shale or coal. The present of macerals in the organic rich source rock such as Liptinite, Vitrinite and Inertinite can all be used to measure the thermal maturity of source rock by measuring their reflectance under the photometer microscope but Vitrinite is normally been used. This is because Vitrinite is not strongly prone to oil and gas formation. It is common as a residue in source rocks which spans from a wide range of depth and temperature. It is always present and not drastically reduces because of its oil and gas generation. Thus, it can be found within the whole range of maturity of source rock and using its different reflectance in different maturity to indicate the maturity. Like Liptinite which is oil prone, will generate oil in oil window and then drastically reduce in quantity after it is approaching to the end of oil window. Thus, the maturity of the source rock after that cannot be determined because the liptinite is very less or nearly disappear after the maturity of generating oil. In this case, Vitrinite presence is quite constant. Inertinite is seldom been used because it is present in post-maturity source rock which we are not interested. The review of Vitrinite evolution and changing of reflectance As the source rock is being buried deeper and deeper, the temperature is higher and higher and the time where the kerogen splits into its four distinctive types is called Carbonization Jump. At here, the organic compounds undergo reordering and become aligned parallel to the bedding. The Vitrinite has become dense Vitrinite. The source rock is continuing being buried deeper and temperature increases. The chemical composition of the Vitrinite will correspondingly alter, increasing the reflectivity of Vitrinite. Therefore, the percentage reflection of a beam of normal incident white light from the surface of a polished Vitrinite is a function of the maturity of the maceral and source rock.Thus, at different depth and temperature, the Vitrinite reflectance is different and from the Vitrinite

Figure 5: Mass spectra

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reflectance, the maturity is measured. The vitrinite reflectance value, Vro for oil window is 0.5; Vro for gas window is 1.2. Comparison Kerogen types are determined by the Von Krevelin graph or hydrogen index (HI) against oxygen index (OI) graph which both the indexes can be measured using Rock Eval. Without using Rock Eval, we can also predict the kerogen types by looking at the macerals in the source rock. The presence of liptinite which is oil prone is corresponding to the kerogen type I and II; Vitrinite which is oil and gas prone is corresponding to the kerogen type III; Inertinite which is non-hydrocarbon producing is corresponding to the kerogen type IV. Material: Source rock, resin, and hardener

Apparatus: Grinder, sieve, polish machine, and photometer microscope

Methodology:

1. The source rock is crushed into fine powder using grinder and then sieved. 2. The powdered source rock will then be mounted into a cylinder shape by using resin and

hardener. 3. This resin block is grounded and polished to a high standard. Poor polishing will lead to spurious

reflection measurements. 4. The photometer microscope is calibrated using sapphire or garnet. 5. The polished resin block is then inspected under the photometer microscope to measure the

Vitrinite reflectance. Normally 30 to 100 vitrinite measurements are taken. 6. The vitrinite reflectance value, Vro can be used to find the depth of oil and gas windows,

igneous intrusion, unconformity and structural deformation such as fault. All these can be found using the Log Vro against depth graph.

LECO – Multiphase Carbon Determinator The objective of this lab is to find the Total Organic Carbon (TOC) of the source rock. Material: Grain size source rock Apparatus: Weight balance and quartz boat Methodology:

1. The source rock is crushed into small grain size. 2. 0.5gram of the crushed source rock is weighed using weight balance and then transferred onto

the quartz boat. 3. At first the machine is being run without a sample to burn out moisture and possible carbon-

bearing phase presents.

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4. A calibration for carbon dioxide, CO2 and moisture, H2O is done with corresponding standards using mixture of calcite and gypsum.

5. Then, the loaded quartz boat is inserted into the combustion tube. 6. The furnace control system can control the temperature to be stepped and subjected to

ramping. Since various sources of carbon oxidize, decompose or turn into volatiles in different temperature, the temperature profile is completely programmable into 10 different phases. Just set the starting temperature, end temperature, ramping rate and the amount of time to hold at the ending temperature for each of the phases selected.

7. For analysing TOC, the source rock is normally heated from 350oC to 950oC. (This machine can heat up to 2000oC.)

8. The source rock is combusted using oxygen. Its organic compound and hydrocarbons content are cracked and oxidized to release carbon dioxide, CO2 and moisture, H2O. The CO2 and H2O are then measures using Infrared absorption cells detector. The presence of organic carbon may be verified by finding coincident peaks in H2O and CO2.

9. After that, the source rock is ignited in an inert N2 atmosphere with the afterburner and oxidation catalysts at 120oC. In here, only moisture and carbonate will be detected but not the organic carbon.

10. The result is printed out showing the TOC, moisture and carbonate value. 11. When the analysis is completed, the source rock is removed from the combustion tube.

Rock-Eval Pyrolyzer

The objective of this lab is to identify the potential source rock by using the S1, S2 and S3 peak of the Rock Eval analysis. The Rock-Eval Pyrolyzer is actually running a test to determine the bitumen or hydrocarbon that is readily present in the source rock (S1); cracking the kerogen in the source rock to produce hydrocarbon (S2); carbon dioxide, CO2 in (S3) is used to calculate the amount of oxygen readily present in the source rock. The hydrocarbon index (HI), oxygen index (OI) and production index (PI) can be calculated using S1, S2, S3 and TOC. These indexes will then be used to identify the kerogen type in the source rock. Material: Grain size source rock Apparatus: Weight balance Methodology:

1. The source rock is crushed into small grain size.

2. 60mg of the crushed source rock is weighed using weight balance.

3. The crushed source rock is inserted into the Rock-Eval Pyrolyzer.

4. The crushed source rock is heated in the inert atmosphere with helium.

5. The pyrolysis oven heated and kept isothermally at 300°C for 3 minutes.

6. The free hydrocarbons are volatilized, detected by flame ionization detector (FID) and

measured as the S1 peak.

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7. The temperature is then increased from 300° to 600°C at the rate of 25°C/min. This is the phase

of volatilization of the very heavy hydrocarbons compounds (>C40) as well as the cracking of

nonvolatile organic matter. The hydrocarbons released from this thermal cracking are

measured as the S2 peak by flame ionization detector (FID). The temperature at which S2

reaches its maximum depends on the nature and maturity of the kerogen and is called Tmax.

8. The CO2 escaped from the kerogen cracking is trapped in the 300°-390°C range. This trap is

heated and the CO2 is released and detected by thermal conductivity detector (TCD) as S3 peak

during the cooling of the pyrolysis oven.

9. The S1, S2 and S3 result is printed out.

10. If S1 is lower and S2 is higher peak, this indicate the rock sample is not yet thermally mature

enough to produce hydrocarbon but has the potential to be a source rock.

11. The hydrocarbon index (HI),

1. Oxygen index (OI),

2. Production index (PI),

3. Kerogen types are determined by the Von Krevelin graph or hydrogen index (HI) against oxygen

index (OI) graph.